Maternal Body Weight Prior to and Following Pregnancy

1. Maternal Body Weight Prior to and Following Pregnancy LCDR Andrea Sharma, PhD, MPH Division of Nutrition, Physical Activity and Obesity National Center for Chronic Disease Prevention and Health Promotion Centers for Disease Control and Prevention

2. Context: New Pregnancy Weight Gain Guidelines 1990, Institute of Medicine (IOM), Nutrition During Pregnancy Pregnancy weight gain (PWG) guidelines based on prepregnant BMI Poor maternal nutrition and PWG results in small for gestational age Reexamination of PWG guidelines Obesity epidemic Excess gestational weight gain Short- and long-term outcomes for both mother and child Good morning, It�s a pleasure to be here. To set the context of my presentation today, let me begin by giving a brief overview of the Institute of Medicine�s reexamination of pregnancy weight gain recommendations. New recommendations just came out last week. In 1990, the IOM published its landmark report, Nutrition during Pregnancy, which included recommended ranges for the amount of weight a woman should gain during pregnancy depending on her prepregnant body mass index. At the time, the primary pregnancy outcome of interest was fetal growth, and the concern was that poor maternal nutrition and low pregnancy weight gain results in small for gestational age infants who are at greater risk of failure to thrive and poor development. In the years since the 1990 report, there have been dramatic shifts in the demographic and epidemiologic profile of the US population. Notably, we now have an obesity epidemic and excess PWG has increased across all population groups, particularly minority groups. Also, in addition to fetal growth, there is also now interest both the short and long-term outcomes for both the mother and the child. In 2008, my Division (DNPAO) co-sponsored IOM to reexamine PWG guidelines and today I�ll present 2 pieces of information requested by the IOM committee for their deliberations.Good morning, It�s a pleasure to be here. To set the context of my presentation today, let me begin by giving a brief overview of the Institute of Medicine�s reexamination of pregnancy weight gain recommendations. New recommendations just came out last week. In 1990, the IOM published its landmark report, Nutrition during Pregnancy, which included recommended ranges for the amount of weight a woman should gain during pregnancy depending on her prepregnant body mass index. At the time, the primary pregnancy outcome of interest was fetal growth, and the concern was that poor maternal nutrition and low pregnancy weight gain results in small for gestational age infants who are at greater risk of failure to thrive and poor development. In the years since the 1990 report, there have been dramatic shifts in the demographic and epidemiologic profile of the US population. Notably, we now have an obesity epidemic and excess PWG has increased across all population groups, particularly minority groups. Also, in addition to fetal growth, there is also now interest both the short and long-term outcomes for both the mother and the child. In 2008, my Division (DNPAO) co-sponsored IOM to reexamine PWG guidelines and today I�ll present 2 pieces of information requested by the IOM committee for their deliberations.

3. Presentation Overview 1. Describe distribution and trends in BMI among women of reproductive age in the U.S. Describe associations between PWG and post-partum weight retention Summarize briefly new IOM recommendations The first part of my presentation will focus on the distribution and trends in body mass index among women of reproductive age. This information was used to inform the IOM committee on the proportion of women who may enter pregnancy below or above a normal weight. The second part of my presentation focuses on associations between PWG and postpartum weight retention. Because excess weight gained during pregnancy can increase risk for later obesity, The IOM committee was interested in understanding the potential implications of PWG on maternal obesity. Finally, Because the final IOM recommendations were released last Thursday, I�ll also quickly summarize the new recommendations.The first part of my presentation will focus on the distribution and trends in body mass index among women of reproductive age. This information was used to inform the IOM committee on the proportion of women who may enter pregnancy below or above a normal weight. The second part of my presentation focuses on associations between PWG and postpartum weight retention. Because excess weight gained during pregnancy can increase risk for later obesity, The IOM committee was interested in understanding the potential implications of PWG on maternal obesity. Finally, Because the final IOM recommendations were released last Thursday, I�ll also quickly summarize the new recommendations.

4. Trends and Distribution of BMI among Women of Reproductive Age I�ll begin with the distribution and trends in BMI among women of reproductive age.I�ll begin with the distribution and trends in BMI among women of reproductive age.

5. Data Source National Health and Nutrition Examination Survey (NHANES) US civilian, non-institutionalized population Height and weight measured For this analysis, I used data from the National health and nutrition examination survey (NHANES). NHANES is a series of cross-sectional surveys which use a Complex, Multistage probability sampling design to provide nationally representative data for the US civilian, non-institutionalized population. During each survey, participants receive a physical exam where Ht and wt measured using standardized protocols and calibrated equipment. NHANES is our only source of measured anthropometry that is nationally representative. For this analysis, I used data from the National health and nutrition examination survey (NHANES). NHANES is a series of cross-sectional surveys which use a Complex, Multistage probability sampling design to provide nationally representative data for the US civilian, non-institutionalized population. During each survey, participants receive a physical exam where Ht and wt measured using standardized protocols and calibrated equipment. NHANES is our only source of measured anthropometry that is nationally representative.

6. Classification* of adult underweight, overweight and obesity by BMI Weight status in adults is categorized using body mass index, which is calculated as weight in kilograms divided by height in meters squared. BMI describes relative weight for height and is correlated with total body fat content. Based on BMI, you are categorized as either underweight, normal weight, overweight or obese. Among the obese, there are also 3 classifications that describe the severity of obesity. Weight status in adults is categorized using body mass index, which is calculated as weight in kilograms divided by height in meters squared. BMI describes relative weight for height and is correlated with total body fat content. Based on BMI, you are categorized as either underweight, normal weight, overweight or obese. Among the obese, there are also 3 classifications that describe the severity of obesity.

7. Historical trends in obesity among U.S. women aged 20-39 years, 1960-2006 This slide describes the historical trends in obesity among women 20-39 years of age, with prevalence on the y-axis and survey year on the x-axis. Just as a note, For the rest of my presentation, I�ll focus on adult women aged 20-49, but I wasn�t able to get historical data on that exact age group. This pattern was similar across adult women. From this slide you can see that the prevalence of obesity was around 10% until 1980. From 1980 to about 2000 the prevalence of obesity has more than doubled such that about 30% of women age 20-39 were obese. Since the 1999-2000 survey, surveys suggest that we may be reaching a plateau in the prevalence of obesity among women as there has been no significant trend from 1999-2006. I also wanted to point out that obesity is one of the priority health indicators in Healthy People 2010 as its viewed to be a significant, and preventable public health threat. The HP 2010 object (19-2), reduce the proportion of adults who are obese to 15%. This slide describes the historical trends in obesity among women 20-39 years of age, with prevalence on the y-axis and survey year on the x-axis. Just as a note, For the rest of my presentation, I�ll focus on adult women aged 20-49, but I wasn�t able to get historical data on that exact age group. This pattern was similar across adult women. From this slide you can see that the prevalence of obesity was around 10% until 1980. From 1980 to about 2000 the prevalence of obesity has more than doubled such that about 30% of women age 20-39 were obese. Since the 1999-2000 survey, surveys suggest that we may be reaching a plateau in the prevalence of obesity among women as there has been no significant trend from 1999-2006. I also wanted to point out that obesity is one of the priority health indicators in Healthy People 2010 as its viewed to be a significant, and preventable public health threat. The HP 2010 object (19-2), reduce the proportion of adults who are obese to 15%.

8. Change in the distribution of BMI between 1988-94 and 2005-06 among U.S. women aged 20-49 years Although we�ve seen an increase in obesity prevalence, changes in the prevalence don�t present a complete picture of the trends in BMI. This slide shows the distribution of BMI among women aged 20-49 years during the 1988-94 NHANES III survey and the most recent 2005-2006 survey. You can see that the distribution of BMI has shifted to the right but the shift was greatest at the upper percentiles of the distribution. In the tables below each figure, I�ve listed BMI at various percentiles. At the 10th percentile there�s been about a one-unit increase in BMI, at a given height this is a shift of about 6 lbs. about 2 units at the 50th percentile, 12 lbs, and almost 4 units at the 90th percentile, which is about 25 lbs. This indicates that not only have women of reproductive age become heavier, but the heaviest women have become much heavier. Although we�ve seen an increase in obesity prevalence, changes in the prevalence don�t present a complete picture of the trends in BMI. This slide shows the distribution of BMI among women aged 20-49 years during the 1988-94 NHANES III survey and the most recent 2005-2006 survey. You can see that the distribution of BMI has shifted to the right but the shift was greatest at the upper percentiles of the distribution. In the tables below each figure, I�ve listed BMI at various percentiles. At the 10th percentile there�s been about a one-unit increase in BMI, at a given height this is a shift of about 6 lbs. about 2 units at the 50th percentile, 12 lbs, and almost 4 units at the 90th percentile, which is about 25 lbs. This indicates that not only have women of reproductive age become heavier, but the heaviest women have become much heavier.

9. Prevalence of underweight, overweight and obesity among U.S. women aged 20-49 y We can also see this shift in the prevalence of extreme obesity. Let me take a minute to orient you to this slide. Survey year is on the x-axis, beginning with the 1988-94 NHANES III survey. Percent is on the y-axis and I�ve colored coded the percent of 20-49 year old women who were underweight, normal weight, overweight or obese for each survey. Beginning at the top with obesity, you can again see that not only has obesity increased from about 22% in 1988-94 to about 35% in 2005-06, which is about a 57% relative increase, but the prevalence of extreme obesity has also increased from about 4% to about 7%, which is about a 90% relative increase. If we look at underweight at the bottom, we can see that the prevalence of underweight has remaining relatively constant at about 3-4% among reproductive age women. So over the past 2 decades, women have become heavier, the severity of obesity has increased, but underweight has remained relatively unchanged.We can also see this shift in the prevalence of extreme obesity. Let me take a minute to orient you to this slide. Survey year is on the x-axis, beginning with the 1988-94 NHANES III survey. Percent is on the y-axis and I�ve colored coded the percent of 20-49 year old women who were underweight, normal weight, overweight or obese for each survey. Beginning at the top with obesity, you can again see that not only has obesity increased from about 22% in 1988-94 to about 35% in 2005-06, which is about a 57% relative increase, but the prevalence of extreme obesity has also increased from about 4% to about 7%, which is about a 90% relative increase. If we look at underweight at the bottom, we can see that the prevalence of underweight has remaining relatively constant at about 3-4% among reproductive age women. So over the past 2 decades, women have become heavier, the severity of obesity has increased, but underweight has remained relatively unchanged.

10. Trends in obesity among U.S. women of reproductive age by age group, 1988-2006 Here I�ve illustrated obesity trends across age groups beginning with the 1988-94 survey. You can see that across all surveys the prevalence of obesity is higher with age. As you recall from an earlier slide data from the most recent years suggest a plateau. This may be driven by the younger age group which is consistent with recent data published on children and adolescents. It will be interesting to see what happens as this cohort ages in future surveys. 20-20, 15-25% 30-39, 25-38% 40-49, 26-41%Here I�ve illustrated obesity trends across age groups beginning with the 1988-94 survey. You can see that across all surveys the prevalence of obesity is higher with age. As you recall from an earlier slide data from the most recent years suggest a plateau. This may be driven by the younger age group which is consistent with recent data published on children and adolescents. It will be interesting to see what happens as this cohort ages in future surveys. 20-20, 15-25% 30-39, 25-38% 40-49, 26-41%

11. Prevalence of overweight and obesity among U.S. women aged 20-49 years by age group, 2005-2006 These are our most recent estimates of overweight and obesity stratified by age. These estimates pool 2 years of data from 2005-6. 58% total Just under 50% of 20-29 y women are above a normal weight being overweight or obese, whereas 60% or more of 30-49 y old women are overweight or obese. Obese and overwt+, 20 diff from 30 and 40 Overwt, no diffsThese are our most recent estimates of overweight and obesity stratified by age. These estimates pool 2 years of data from 2005-6. 58% total Just under 50% of 20-29 y women are above a normal weight being overweight or obese, whereas 60% or more of 30-49 y old women are overweight or obese. Obese and overwt+, 20 diff from 30 and 40 Overwt, no diffs

12. Trends in obesity among U.S. women aged 20-49 years by race/ethnicity, 1988-2006 Here I�ve illustrated obesity trends across race/ethnic groups beginning with the 1988-94 survey. You can see that across all surveys the prevalence of obesity is consistently higher among non-hispanic Black and mexican american women than white women. White 20-32% Mexican 32-41% Black 34-49% Only white sigHere I�ve illustrated obesity trends across race/ethnic groups beginning with the 1988-94 survey. You can see that across all surveys the prevalence of obesity is consistently higher among non-hispanic Black and mexican american women than white women. White 20-32% Mexican 32-41% Black 34-49% Only white sig

13. Prevalence of overweight and obesity among U.S. women aged 20-49 years by race/ethnicity, 2005-2006 These are our most recent estimates of overweight and obesity stratified by race/ethnicity. These estimates pool 2 years of data from 2005-6. ABout 50% of nh-white women are overweight or obese, whereas 78% of nh-black and 70% of mexican american women are overweight or obese. Obese, white diff black overwt+, white diff black and mex Overwt white diff black and mex These are our most recent estimates of overweight and obesity stratified by race/ethnicity. These estimates pool 2 years of data from 2005-6. ABout 50% of nh-white women are overweight or obese, whereas 78% of nh-black and 70% of mexican american women are overweight or obese. Obese, white diff black overwt+, white diff black and mex Overwt white diff black and mex

14. Prevalence of underweight among U.S. women aged 20-49 years by race/ethnicity, 2001-2006 This slide shows prevalance of underweight, the highest prevalence is among nh white women and the lowest among mex am women. White diff from mex am. This slide shows prevalance of underweight, the highest prevalence is among nh white women and the lowest among mex am women. White diff from mex am.

15. Summary Underweight relatively stable Since 1980, obesity doubled among women but may be reaching a plateau More than 58% of reproductive age women above a normal weight Racial disparities Obesity higher among older populations In summary, the prevalence of Underweight has remained relatively low at 3%, with the highest prevalence of underweight observed among non-Hispanic white women. Since 1980, obesity has more than doubled among women. However, we are cautiously optimistic that obesity may be reaching a plateau. We will need a few more years of data to be certain, but it does appear that the epidemic is slowing down if not leveling off. We are however far from reaching Healthy People 2010 objectives, and have yet to turn the obesity trends around. Currently in the US, 58% of women of reproductive age are above a normal weight. This is significant because women who enter pregnancy with a BMI above normal are more likely to experience preeclampsia, Gestational diabetes, caesarian delivery, and failure to initiate and sustain breastfeeding. Obesity is far more common among racial or ethnic minority groups and increases in prevalence with advancing age. This information was really used to set the stage for the IOM committee. How have reproductive age women changed in the past 30 years? We have moved from being worried about under nutrition during pregnancy to being concerned about over nutrition and morbidities associated with obesity. In summary, the prevalence of Underweight has remained relatively low at 3%, with the highest prevalence of underweight observed among non-Hispanic white women. Since 1980, obesity has more than doubled among women. However, we are cautiously optimistic that obesity may be reaching a plateau. We will need a few more years of data to be certain, but it does appear that the epidemic is slowing down if not leveling off. We are however far from reaching Healthy People 2010 objectives, and have yet to turn the obesity trends around. Currently in the US, 58% of women of reproductive age are above a normal weight. This is significant because women who enter pregnancy with a BMI above normal are more likely to experience preeclampsia, Gestational diabetes, caesarian delivery, and failure to initiate and sustain breastfeeding. Obesity is far more common among racial or ethnic minority groups and increases in prevalence with advancing age. This information was really used to set the stage for the IOM committee. How have reproductive age women changed in the past 30 years? We have moved from being worried about under nutrition during pregnancy to being concerned about over nutrition and morbidities associated with obesity.

16. Pregnancy Weight Gain and Postpartum Weight Retention As part of the reexamination of PWG guidelines, more attention was given to maternal outcomes. One outcome in particular the IOM committee was interested in was the impact of pregnancy weight gain on postpartum weight retention as this may further increase a woman�s risk for obesity. In the next few slides I�ll summarize some data we provided to the committee per their request.As part of the reexamination of PWG guidelines, more attention was given to maternal outcomes. One outcome in particular the IOM committee was interested in was the impact of pregnancy weight gain on postpartum weight retention as this may further increase a woman�s risk for obesity. In the next few slides I�ll summarize some data we provided to the committee per their request.

17. Data Source Pregnancy Nutrition Surveillance System (PNSS) Low-income mothers Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) 2004-2006 Singleton, term pregnancies About 1.4 million records We used data from the Pregnancy Nutrition Surveillance System, or PNSS. PNSS was designed to monitor the nutritional status of low-income pregnant mothers, and the behavioral risk-factors associated with birth outcomes. The majority of data are collected from WIC program records and currently 28 states, the District of Columbia, four tribal governments, and one U.S. territory contribute data into PNSS. Data are collected on mothers during their initial prenatal visit to the WIC clinic and during the postpartum visit. For this analysis, we used data from 2004 to 2006 and included mothers with singleton-term pregnancies who had a postpartum visit which was over 1.4 million records. We used data from the Pregnancy Nutrition Surveillance System, or PNSS. PNSS was designed to monitor the nutritional status of low-income pregnant mothers, and the behavioral risk-factors associated with birth outcomes. The majority of data are collected from WIC program records and currently 28 states, the District of Columbia, four tribal governments, and one U.S. territory contribute data into PNSS. Data are collected on mothers during their initial prenatal visit to the WIC clinic and during the postpartum visit. For this analysis, we used data from 2004 to 2006 and included mothers with singleton-term pregnancies who had a postpartum visit which was over 1.4 million records.

18. Data Analysis Descriptive analysis and logistic regression Postpartum weight retention= Postpartum weight - Prepregnant weight Time postpartum (<12, 12-24, >24 wks) Prepregnant BMI category Pregnancy weight gain category Underweight 28-40 lbs Normal weight 25-35 lbs Overweight 15-25 lbs Obese 15-25 lbs* Race/ethnicity For this analysis we conducted Basic Descriptive statistics and performed logistic regression to determine the odds of retaining more than 10 lbs postpartum. We calculated postpartum weight retention as the difference between postpartum weight, which was measured during the postpartum clinic visit, and prepregnant weight, which was self-reported. We calculated the mean wt retained and the proportion of women who retained more than 10 lbs at 3 time points postpartum, <12 weeks, 12-24 weeks, and >24 weeks. We then examined weight retention by prepregnant BMI category, PWG category (whether a mother had PWG below, within or above recommendations). I�ve listed the 1990 recommendations here. For obese mothers, we used 15-25 pounds as the recommended weight because there was no range provided in the 1990 recommendations. We also examined whether associations differed across prepregnant BMI or racial/ethnic groups. For sake of time, I am only Presenting select results today. (Pregnancy weight gain was self-reported by the mother during a post-partum visit.) For this analysis we conducted Basic Descriptive statistics and performed logistic regression to determine the odds of retaining more than 10 lbs postpartum. We calculated postpartum weight retention as the difference between postpartum weight, which was measured during the postpartum clinic visit, and prepregnant weight, which was self-reported. We calculated the mean wt retained and the proportion of women who retained more than 10 lbs at 3 time points postpartum, <12 weeks, 12-24 weeks, and >24 weeks. We then examined weight retention by prepregnant BMI category, PWG category (whether a mother had PWG below, within or above recommendations). I�ve listed the 1990 recommendations here. For obese mothers, we used 15-25 pounds as the recommended weight because there was no range provided in the 1990 recommendations. We also examined whether associations differed across prepregnant BMI or racial/ethnic groups. For sake of time, I am only Presenting select results today. (Pregnancy weight gain was self-reported by the mother during a post-partum visit.)

19. Population Characteristics Our study population was about 25 years old, 50% were non-Hispanic white and the majority had a high school education or less. About 45% were normal weight and 50% weight either overweight or obese. Almost half of mothers gained pregnancy weight above the 1990 recommendations.Our study population was about 25 years old, 50% were non-Hispanic white and the majority had a high school education or less. About 45% were normal weight and 50% weight either overweight or obese. Almost half of mothers gained pregnancy weight above the 1990 recommendations.

20. Mean weight retained over time by prepregnant BMI The next 2 slides show mean postpartum weight retained over time, so let me take a minute to orient you. Each figure shows a different prepregnant BMI group with the specific PWG recommendations for that BMI category. Mean weight retained is on the y-axis and weeks postpartum is on the x-axis. The bottom green line shows the mean weight retained among mothers who gained less than recommended pregnancy weight, the middle yellow line is mean weight retained among mothers who gained within recommendations, and the top blue line is mean weight retained among mothers who gained in excess of recommendations. What I would like you to notice is the pattern across prepregnant BMI groups. Among all groups, mean weight retained is higher over time among mothers who gained more weight during pregnancy. But you will notice that among underweight and normal weight mothers, retained pregnancy weight tends to decrease over time.The next 2 slides show mean postpartum weight retained over time, so let me take a minute to orient you. Each figure shows a different prepregnant BMI group with the specific PWG recommendations for that BMI category. Mean weight retained is on the y-axis and weeks postpartum is on the x-axis. The bottom green line shows the mean weight retained among mothers who gained less than recommended pregnancy weight, the middle yellow line is mean weight retained among mothers who gained within recommendations, and the top blue line is mean weight retained among mothers who gained in excess of recommendations. What I would like you to notice is the pattern across prepregnant BMI groups. Among all groups, mean weight retained is higher over time among mothers who gained more weight during pregnancy. But you will notice that among underweight and normal weight mothers, retained pregnancy weight tends to decrease over time.

21. Mean weight retained over time by prepregnant BMI However, among overweight and obese mothers, there tends to be little decrease in retained pregnancy weight over time, and in fact suggestion that weight increases. This is consistent with other studies that have found that women who begin pregnancy at a higher BMI tend to stay on the same weight trajectory postpartum.However, among overweight and obese mothers, there tends to be little decrease in retained pregnancy weight over time, and in fact suggestion that weight increases. This is consistent with other studies that have found that women who begin pregnancy at a higher BMI tend to stay on the same weight trajectory postpartum.

22. Weight retention of >10 lbs at 24+ wks postpartum, by PWG status Using logistic regression, We found no meaningful difference in the association between PWG and postpartum weight retention after 6 months postpartum by prepregnant BMI group or race/ethnic group. So I will not present any stratified results. This slide shows the proportion of women who retained more than 10 lbs after 6 months postpartum according to meeting PWG recommendations. I�ve colored the middle bar lighter to indicate the recommended PWG group. 68% of women who exceeded PWG recommendations had retained more than 10 lbs after 6 months postpartum compared to 42% who gained within recommendations and 27% who gained below recommendations. Using logistic regression we found that Relative to those who gained within recommendations, women who gained above recommendations were 3.2 times as likely to retain more than 10 lbs after 6 months postpartum. These associations similar across race/ethnic groups. Using logistic regression, We found no meaningful difference in the association between PWG and postpartum weight retention after 6 months postpartum by prepregnant BMI group or race/ethnic group. So I will not present any stratified results. This slide shows the proportion of women who retained more than 10 lbs after 6 months postpartum according to meeting PWG recommendations. I�ve colored the middle bar lighter to indicate the recommended PWG group. 68% of women who exceeded PWG recommendations had retained more than 10 lbs after 6 months postpartum compared to 42% who gained within recommendations and 27% who gained below recommendations. Using logistic regression we found that Relative to those who gained within recommendations, women who gained above recommendations were 3.2 times as likely to retain more than 10 lbs after 6 months postpartum. These associations similar across race/ethnic groups.

23. Limitations Self-reported prepregnant weight and PWG No data on diet, physical activity, breastfeeding duration Not nationally representative Majority of data <12 wks postpartum This study has some limitations. First, prepregnant weight and pregnancy weight gain were based on self-reported data, and thus may have led to misclassification. It is possible that we have not controlled for all sources of confounding, such as diet, physical activity and breastfeeding duration which are all associated with prepregnant BMI, PWG and postpartum weight retention. Our study sample was not nationally representative. Therefore the results may not be generalizable to all U.S. women, but this is a high-risk population known to have an increase risk of excess PWG and obesity. Finally, the majority of our records were from clinic visits <12 postpartum which is likely too close to birth to adequately assess postpartum weight retention. Although, we had About 50,000 records with postpartum visit between 6-12 months, women who come in later for their postpartum clinic visit may differ from those who came in earlier. it would be ideal to assess postpartum weight retention across all women closer to 1 year after birth.This study has some limitations. First, prepregnant weight and pregnancy weight gain were based on self-reported data, and thus may have led to misclassification. It is possible that we have not controlled for all sources of confounding, such as diet, physical activity and breastfeeding duration which are all associated with prepregnant BMI, PWG and postpartum weight retention. Our study sample was not nationally representative. Therefore the results may not be generalizable to all U.S. women, but this is a high-risk population known to have an increase risk of excess PWG and obesity. Finally, the majority of our records were from clinic visits <12 postpartum which is likely too close to birth to adequately assess postpartum weight retention. Although, we had About 50,000 records with postpartum visit between 6-12 months, women who come in later for their postpartum clinic visit may differ from those who came in earlier. it would be ideal to assess postpartum weight retention across all women closer to 1 year after birth.

24. Summary Excess PWG common PWG associated with postpartum weight retention Patterns of postpartum weight loss differ by prepregnant BMI Little difference in weight retention by race/ethnicity or prepregnant BMI In summary, Excess PWG is common with Over half of the mothers in this low-income population gaining above recommendations. PWG is associated with postpartum weight retention. This is of concern, particularly with excess weight gain because increased BMI is associated with many chronic disease morbidities for the mother, and a mother may potentially enter the next pregnancy at a higher weight category which is then associated with a greater risk of pregnancy complications and adverse birth outcomes for the subsequent pregnancy. Descriptive analysis shows patterns of postpartum weight loss differ by prepregnant BMI, but by 6 months postpartum there was little difference in the odds of retaining more than 10 or 20 lbs by prepregnant BMI or race/ethnicity. At a given height, 10 pounds increases BMI by 1.6 unitsIn summary, Excess PWG is common with Over half of the mothers in this low-income population gaining above recommendations. PWG is associated with postpartum weight retention. This is of concern, particularly with excess weight gain because increased BMI is associated with many chronic disease morbidities for the mother, and a mother may potentially enter the next pregnancy at a higher weight category which is then associated with a greater risk of pregnancy complications and adverse birth outcomes for the subsequent pregnancy. Descriptive analysis shows patterns of postpartum weight loss differ by prepregnant BMI, but by 6 months postpartum there was little difference in the odds of retaining more than 10 or 20 lbs by prepregnant BMI or race/ethnicity. At a given height, 10 pounds increases BMI by 1.6 units

25. Pregnancy Weight Gain Guidelines � Released May 27, 2009 Finally, since the final IOM guidelines were released last Thursday, I�ll just quickly summarize the new guidelines . Finally, since the final IOM guidelines were released last Thursday, I�ll just quickly summarize the new guidelines .

26. New PWG Guidelines Similar to the 1990 guidelines, the new guidelines are based on prepregnant BMI. The new guidelines differ from those issued in 1990 in several ways, First, they are based on WHO BMI categories (shown in yellow), the standard criteria used to assess weight status, instead of the previous ones, Similar to the 1990 guidelines, the new guidelines are based on prepregnant BMI. The new guidelines differ from those issued in 1990 in several ways, First, they are based on WHO BMI categories (shown in yellow), the standard criteria used to assess weight status, instead of the previous ones,

27. New PWG Guidelines Shown in green, which were derived from Metropolitan Life Insurance Tables. This is an important change so women no longer magically change BMI categories when they become pregnant. Shown in green, which were derived from Metropolitan Life Insurance Tables. This is an important change so women no longer magically change BMI categories when they become pregnant.

28. New PWG Guidelines Secondly, and probably most importantly, the new guidelines include a specific, relatively narrow range of recommended gain for obese women. So the recommended range of PWG for Underweight women of 28-40 lbs, normal weight 25-35 lbs and overweight 15-25 lbs has not changed, but in the 1990 guidelines there was no range provided for obese women due to lack of data. Obese women were advised to gain at least 15 lbs but no maximum weight gain was established. This is a important piece of information to give guidance to obese mothers, but I should note that The range for obese women really comes from data for women with a BMI of 30-35; data were insufficient to create recommendations specific to the heavier classes of obese women, where further research may well suggest that lower gains might be desirable.Secondly, and probably most importantly, the new guidelines include a specific, relatively narrow range of recommended gain for obese women. So the recommended range of PWG for Underweight women of 28-40 lbs, normal weight 25-35 lbs and overweight 15-25 lbs has not changed, but in the 1990 guidelines there was no range provided for obese women due to lack of data. Obese women were advised to gain at least 15 lbs but no maximum weight gain was established. This is a important piece of information to give guidance to obese mothers, but I should note that The range for obese women really comes from data for women with a BMI of 30-35; data were insufficient to create recommendations specific to the heavier classes of obese women, where further research may well suggest that lower gains might be desirable.

29. Guidelines for special populations No modifications for: Short stature Young age Racial/ethnic subgroups Primiparity Smokers Multiple Fetuses Underweight insufficient data Normal weight 37-54 lbs Overweight 31-50 lbs Obese 25-42 lbs In contrast to the 1990 report, there were no modifications to the guidelines for many special populations. In 1990, short mothers were advised to gain on the lower end of the range for their BMI category, while young women and black women were advised to gain on the upper end of the range. There are now no special modifications for these groups or for primiparious or smoking mothers. Finally, 1990, mothers carrying twins were advised to gain 35-45 lbs, and there was insufficient data to break down by prepregnant BMI. The new guidelines provide provisional recommendations for twin pregnancies by prepregnant BMI, but there was insufficient data to provide a range for underweight mothers. In contrast to the 1990 report, there were no modifications to the guidelines for many special populations. In 1990, short mothers were advised to gain on the lower end of the range for their BMI category, while young women and black women were advised to gain on the upper end of the range. There are now no special modifications for these groups or for primiparious or smoking mothers. Finally, 1990, mothers carrying twins were advised to gain 35-45 lbs, and there was insufficient data to break down by prepregnant BMI. The new guidelines provide provisional recommendations for twin pregnancies by prepregnant BMI, but there was insufficient data to provide a range for underweight mothers.

30. Thank You! Contact Information: LCDR Andrea Sharma, PhD, MPH Division of Nutrition, Physical Activity and Obesity AJSharma@cdc.gov 770-488-5957 For information on new PWG guidelines: http://www.iom.edu/CMS/3788/48191/68004.aspx THANK YOU! THANK YOU!

32. New PWG Guidelines Similar to the 1990 guidelines, the new guidelines are based on prepregnant BMI. Similar to the 1990 guidelines, the new guidelines are based on prepregnant BMI.

33. Odds of retaining >10 lbs among those gaining above 1990 recs, relative to adequate PWG in each R/E group

34. Weight retention > 24 wks postpartum, by prepregnant BMI and PWG Using logistic regression, We found no meaningful difference in the association between PWG and postpartum weight retention after 6 months postpartum by prepregnant BMI group or race/ethnic group. So I will not present any stratified results. This slide shows the proportion of women who retained more than 10 lbs after 6 months postpartum according to prepregnant BMI category and PWG recommendations. I�ve colored the middle bars lighter to indicate the recommended PWG range for each BMI category. Again, the proportion of women retaining more than 10 lbs afer 6 months postpartum is higher among those who gained above recommendations. Using logistic regression we found that Relative to those who gained within recommendations, women who gained above recommendations were 3.2 times as likely to retain more than 10 lbs after 6 months postpartum. Associations similar across race/ethnic groups Using logistic regression, We found no meaningful difference in the association between PWG and postpartum weight retention after 6 months postpartum by prepregnant BMI group or race/ethnic group. So I will not present any stratified results. This slide shows the proportion of women who retained more than 10 lbs after 6 months postpartum according to prepregnant BMI category and PWG recommendations. I�ve colored the middle bars lighter to indicate the recommended PWG range for each BMI category. Again, the proportion of women retaining more than 10 lbs afer 6 months postpartum is higher among those who gained above recommendations. Using logistic regression we found that Relative to those who gained within recommendations, women who gained above recommendations were 3.2 times as likely to retain more than 10 lbs after 6 months postpartum. Associations similar across race/ethnic groups

35. Classification of adolescent* underweight, overweight and obesity by gender- and age-specific BMI percentile Now I�ll focus on adolescent girls. Similar to adults, we calculate BMI for children. But because BMI among children varies considerably with age, we compare a child�s BMI to a reference population of children of the same sex and age. In the US, we are currently using the 2000 CDC growth charts. Based on the growth charts, Underweight is defined as a BMI below the 5th percentile for sex-and age. Overweight as a BMI at or above the 85th percentile but less than the 95th percentile. Obesity as a BMI at or above the 95th percentile for sex and age. The CDC growth charts were created from national data in the United States collected from 1963 through 1994. Data for the BMI for age charts were collected between 1971 and 1994 for children 2 to 6 years of age and between 1963 and 1980 for children 6 through 19 years of age.Now I�ll focus on adolescent girls. Similar to adults, we calculate BMI for children. But because BMI among children varies considerably with age, we compare a child�s BMI to a reference population of children of the same sex and age. In the US, we are currently using the 2000 CDC growth charts. Based on the growth charts, Underweight is defined as a BMI below the 5th percentile for sex-and age. Overweight as a BMI at or above the 85th percentile but less than the 95th percentile. Obesity as a BMI at or above the 95th percentile for sex and age. The CDC growth charts were created from national data in the United States collected from 1963 through 1994. Data for the BMI for age charts were collected between 1971 and 1994 for children 2 to 6 years of age and between 1963 and 1980 for children 6 through 19 years of age.

36. Trends in obesity among U.S. adolescent girls aged 12-19 years, 1966-2006 Similar to what I showed for adult women, This slide describes the historical trends in obesity among adolescent girls 12-19 years of age, with prevalence on the y-axis and survey year on the x-axis. This slide shows that the prevalence of obesity was around 5% until 1980. From 1980 to about 2000 the prevalence of obesity has tripled such that about 17% of adolescent girls age 12-19 are obese. Since the 1999-2000 survey, our most recent surveys suggest that we may be reaching a plateau in the prevalence of obesity among girls as there is no significant trend from 1999-2006. Among children, The HP 2010 object (19-2), is to reduce the proportion who are obese to 5%.Similar to what I showed for adult women, This slide describes the historical trends in obesity among adolescent girls 12-19 years of age, with prevalence on the y-axis and survey year on the x-axis. This slide shows that the prevalence of obesity was around 5% until 1980. From 1980 to about 2000 the prevalence of obesity has tripled such that about 17% of adolescent girls age 12-19 are obese. Since the 1999-2000 survey, our most recent surveys suggest that we may be reaching a plateau in the prevalence of obesity among girls as there is no significant trend from 1999-2006. Among children, The HP 2010 object (19-2), is to reduce the proportion who are obese to 5%.

37. Prevalence of underweight, overweight and obesity among U.S. adolescent girls aged 12-19 y This slide again shows the prevalence of each BMI category from the 1988-94 survey to the most recent surveys. The figure is colored coded to show the percent of 12-19 year old adolescent girls who were underweight, normal weight, overweight or obese for each survey. Beginning at the top with obesity, you can again see obesity increased from about 11% in 1988-94 to about 18% in 2005-06, which is about a 62% relative increase. If we look at underweight at the bottom, we can see that the prevalence of underweight has remaining relatively constant at about 2-3%. This slide again shows the prevalence of each BMI category from the 1988-94 survey to the most recent surveys. The figure is colored coded to show the percent of 12-19 year old adolescent girls who were underweight, normal weight, overweight or obese for each survey. Beginning at the top with obesity, you can again see obesity increased from about 11% in 1988-94 to about 18% in 2005-06, which is about a 62% relative increase. If we look at underweight at the bottom, we can see that the prevalence of underweight has remaining relatively constant at about 2-3%.

38. Trends in obesity among U.S. adolescent girls aged 12-19 years by race/ethnicity, 1988-2006 Here I�ve illustrated obesity trends across race/ethnic groups beginning with the 1988-94 survey. You can see that across all surveys the prevalence of obesity is consistently higher among non-hispanic Black and mexican american girls than white girls. Here I�ve illustrated obesity trends across race/ethnic groups beginning with the 1988-94 survey. You can see that across all surveys the prevalence of obesity is consistently higher among non-hispanic Black and mexican american girls than white girls.

39. Prevalence of overweight and obesity among U.S. adolescent girls aged 12-19 years by race/ethnicity, 2003-2006 These are our most recent estimates of overweight and obesity stratified by race/ethnicity. These estimates pool 4 years of data from 2003-6. ABout 32% of nh-white adol girls are overweight or obese whereas 45% of nh-black and 37% of Mexican American girls are overweight or obese. Obese, white diff black and mex, black diff mex overwt+, white diff black and mex, black diff mex. Overwt no diffs These are our most recent estimates of overweight and obesity stratified by race/ethnicity. These estimates pool 4 years of data from 2003-6. ABout 32% of nh-white adol girls are overweight or obese whereas 45% of nh-black and 37% of Mexican American girls are overweight or obese. Obese, white diff black and mex, black diff mex overwt+, white diff black and mex, black diff mex. Overwt no diffs

40. Prevalence of overweight and obesity among U.S. adolescent girls aged 12-19 years by race/ethnicity, 2003-2006 And if we focus in on just adolescent girls who are obese, a large proportion have a BMI at or above the 97th percentile. The 97th percentile provides an even higher cut point to identify the heaviest children. As a proportion of those who are obese, 63% white vs 70% black or hisp are at or above the 97th percentile. This slide just indicates that the majority of adolescents girls categorized as obese are above the 97th percentile.And if we focus in on just adolescent girls who are obese, a large proportion have a BMI at or above the 97th percentile. The 97th percentile provides an even higher cut point to identify the heaviest children. As a proportion of those who are obese, 63% white vs 70% black or hisp are at or above the 97th percentile. This slide just indicates that the majority of adolescents girls categorized as obese are above the 97th percentile.

41. Prevalence of underweight among U.S. adolescent girls aged 12-19 years by race/ethnicity, 2001-2006 Because the prevalence is so low, I had to pool 6 years of data to get stable estimates., Among adolescent girls, the highest prevalence of underweight is among nh white girls and the lowest among nh-black girls. Black diff from white and mex. Because the prevalence is so low, I had to pool 6 years of data to get stable estimates., Among adolescent girls, the highest prevalence of underweight is among nh white girls and the lowest among nh-black girls. Black diff from white and mex.