Breastfeeding Behavior and Sleep of New Mothers

1. 2012 National State of the Science Congress on Nursing Research Breastfeeding Behavior and Sleep of New Mothers Therese Doan, RN, PhD, IBCLC San Francisco State University

2. Acknowledgements This study is based on a clinical trial funded by the National Institutes of Health research grant # 2R01-NR005345 , K.A. Lee, P.I. Contributing authors: • Kathryn Lee, RN, PhD, FAAN, CBSM(a) • Caryl Gay, PhD (a) • Holly Kennedy, PhD, CNM (b) • Jack Newman, MD (c) • University of California San Francisco, San Francisco, CA • Yale University School of Nursing, New Haven, CT • Newman Institute of Breastfeeding, Toronto, Canada

3. Significance • Healthy People 2020 objectives for exclusive breastfeeding (EBF): • 46.2% through 3 months of age • 25.5% through 6 months of age • CDC reports proportion of breastfed infants given formula: • 25% before 2 days • 36% before 3 mos • 43% before 6 mos Healthypeople.gov; cdc.gov

4. Known Benefits of Breastfeeding Mother Baby Immunological protection Optimal nutrition Pro- and pre-biotics Metabolic development Neurological development Affection • Recovery from childbirth; helps with body weight loss • Diabetics – glucose control • Prevention of obesity • Bone mineralization • Protection against some type of breast & ovarian cancer • Self esteem Hartmann P. (2009); Riordan & Wambach (2010)

5. Conceptualization of Breastfeeding Breast: “a source of nourishment” “the center of affection and emotion” Feed: “to give food to,” “to eat” and “to be nourished or supported.” Breastfeeding: providing and receiving food coming from mother’s breast or center of affection and emotion Doan (2009)

6. Breastfeeding: Healthy Behavior • Infants: optimal nutrition + nurturing • Mothers: ↓ health risks, ↑ well-being • Economy: ↓ health costs (~ 3-4 billion/yr) • Ecology: ↓ global warming; no waste ☼ Benefits associated with duration and exclusivity Kramer & Karuma (2012)

7. Breastfeeding Behavior • Greatest ↓ in EBF occurs in 1st month postpartum • Formula supplementation → early breastfeeding cessation • A bottle (formula) at bedtime: Popular practice at night time • Low-income, ethnically diverse women are more likely to supplement Doan et al. (2007)

8. Research questions • Is there a difference in night-time sleep of new mothers who breastfed exclusively and mothers who used formula at night (9 pm to 9am)? • Are there differences in sociodemographic characteristics?

9. Three Null Hypotheses • there will be no difference in sociodemographic characteristics between mothers who breastfed exclusively and mothers who gave at least some formula at night; • there will be no difference in objective sleep time as measured by wrist actigraphy between mothers who breastfed exclusively and mothers who gave at least some formula at night; • there will be no difference in the perception of sleep disturbance between mothers who breastfed exclusively and mothers who gave at least some formula at night.

10. Study Design & Method • Longitudinal, comparative • Part of a randomized clinical trial • Recruitment from prenatal clinics and free childbirth preparation classes • Target population: Low-income women

11. Inclusion Criteria English-speaking women expecting first child, at least 18 years of age, not working night shift, not taking sleep medication, and no history of diagnosed sleep or affective disorder.

12. Measures Breastfeeding Behavior determined from infant sleep and feeding diary 9pm - 9am over 3 nights, categorized as: Exclusive Breastfeeding (EBF): 100% breastfeeding or breast milk feeding Formula: any formula

13. Measures, cont. Sociodemographic Characteristics obtained at recruitment when women were screened for eligibility, included: Age Race Marital status Relationship status Education Monthly household income Employment status

14. Sleep Measures Objective Measures of Sleep obtained by actigraph: • total sleep time atnight (TST-night) = average minutes of sleep between 21:00 and 08:59 over 3 nights, • total sleep time during theday (TST-day) = average minutes of sleep between 09:00 and 20:59 over 3 days, • wake after sleep onset (WASO) as % of TST

15. Wrist Actigraphy Counts movements from an extremity Estimates acceleration of the movement Uses movement and speed of movement to estimate total sleep time (TST) and wake time (WASO) Under-estimate sleep in active sleepers Over-estimate sleep in sedentary persons Less invasive than PSG Not able to discern stages (REM or nonREM) of sleep

16. Actigraphy Example: 4 weeks postpartum Not EBF EBF

17. Data analysis • Descriptive means and standard deviations (SD) • Repeated measures analysis of variance (RMANOVA) • Independent t-test • Chi-square test

18. Results

19. Sample characteristics by type of nighttime feeding * t-statistic significant (p= 0.01) ** Chi-square significant (p< 0.05)

20. Sample characteristics by type of nighttime feeding **Chi-square significant (p < 0.05)

21. Sample characteristics by type of nighttime feeding ** Chi-square significant (p < 0.05)

22. Comparison of sleep quantity & quality by time and night feeding group * Time, F(1,116)=28.4, p<.001, η2= .197 * TxG, F(1,116) =6.8, p=.01, η2= .055

23. Comparison of sleep quantity & quality by time and night feeding group *Time, F(1,117) =33.9, p<.001, η2= .225 **Time, F(1,118) =12.8, p<.001, η2= .098

24. Total sleep time at night by time and feeding group

25. Conclusions and Implications for Practice • Exclusive breastfeeding first-time mothers averaged 30 minutes more nocturnal sleep than women who used formula at night. • New mothers should be encouraged to breastfeed exclusively since breastfeeding may promote sleep during postpartum recovery

26. References • Healthy People 2020 Summary of Objectives - Maternal, Infant, and Child Health. 2012. http://healthypeople.gov/2020/topicsobjectives2020/pdfs/MaternalChildHealth.pdf. Accessed Aug 27, 2012. • Breastfeeding Among U.S. Children Born 2000-2008, CDC National Immunization Survey. 2011. http://www.cdc.gov/breastfeeding/data/NIS_data/. Accessed Aug 27, 2012. • Hartmann P. Opening presentation to GOLD 2009. • Riordan J, Wambach K. Women’s health and breastfeeding. Breastfeeding and Human Lactation. 4th ed. Sudbury: Jones & Bartlett; 2010:519-544. • Doan T. Breastfeeding behavior and related factors in predominantly low-income & ethnically diverse dyads: A dissertation study. 2009. • Kramer MS, Kakuma R. Optimal duration of exclusive breastfeeding. Cochrane Database Syst Rev. 2012 Aug 15;8:CD003517.PMID: 22895934 • Doan TH, Gardiner A, Gay CL, Lee KA. Breastfeeding increases sleep duration in new parents. J. Perinat. Neonatal Nurs. 2007;21(3):200-206.