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Prevention of Birth Defects and Disabilities. TH Tulchinsky MD MPH Braun School Public Health 8 Jan 2006. NPH Ch 6. Public Health Importance. Common – 3% of US children Neonatal and infant mortality – 20% of IMR Progress made primary, secondary and tertiary Px
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Prevention of Birth Defects and Disabilities TH Tulchinsky MD MPH Braun School Public Health 8 Jan 2006 NPH Ch 6
Public Health Importance • Common – 3% of US children • Neonatal and infant mortality – 20% of IMR • Progress made primary, secondary and tertiary Px • Preventable – e.g. Folic acid • Education – KABP among women in age of fertility • Screening – PKY, CH etc • Intervention – FA fortification • Human genome project- new science and methods • Long term care – family and societal burden
Causes of Birth Defects • Unknown • Cerebral palsy • Toxic • FAS • Smoking, alcohol, drugs • Genetic • PKU • CH • Thalassemia, Sickle Cell • Tay Sachs etc • Injury • Physiologic • LBW • HDN • Nutritional • Iodine and iron deficiency • Folic acid deficiency • Infectious • Rubella syndrome • STIs – Syphilis, GC, • HIV • CMV
Program Approach • High risk population groups • Multiple causation • Toxic – alcohol, drugs, medications • Nutrition – anemia, HDN • Physiologic - HDN • Infection – syphilis, GC, HIV etc • Genetic screening and counseling • Trauma – accidents and violence • Multiple interventions
Non Genetic Maternal-Fetal Transmission • Physiologic • Rhesus hemolytic anemia (Rh syndrome) • Hemorrhagic disease of newborn (HDN) • Toxic • Thalidomide • Fetal alcohol syndrome • Crack babies • Smoking
GC conjunctivitis Syphilis TB Syphilis Cytomegalovirus HIV/AIDS Congenital rubella Mumps Toxoplasmosis Vaginitis Maternal-Fetal Infectious Transmission
Preventing Infectious Disease Transmission, Mother-Infant • Prevention of Congenital Rubella Syndrome • Immunize school girls • Immunize total population (MMR) • Prevention of Syphilis, GC, CMV and HIV • Educate • Case find • Treat • Contacts ?
GC Opthalmia Neonatorum • Common cause of blindness 19th C • Crede in Vienna experimented with many prophylactic preparations • Silver nitrate • Eradicated GC neonatorum blindness • Mandatory eye care for newborns prevents millions of cases of blindness NPH Ch 6
Cytomegalovirus (CMV) • Occurrence 0.2-2.2% of births worldwide • 10% with congenital CMV symptomatic at birth and 90% have permanent neurologic handicap • Other 90% will have 10% late CNS deficit mainly sensory neuronal hearing loss • Routine screening for asymptomatic CMV at birth (urine viral culture) in first 3 weeks of life • PCR Polymerase chain reaction easier and cheaper • Cost benefit ratio currently in question • Importance for future developments
Birth Defects due to Genetic Disorders • PKU - phenylketonuria • CH – congenital hypothyroidism • Tay-Sachs disease • Sickle Cell anemia • Thalassemia • Cystic Fibrosis • Down’s syndrome • Cataracts • Congenital dislocated hips
Eradication of Beta Thalassemia Major in Cyprus and Sardinia Virtual eradication achieved in endemic areas; Cyprus, 14% of the population carriers of Beta Thalassemia, and 1% of (1 in 158 births) had the disease. Now, rare in Cyprus, Sardinia, Greece, UK. Long-term program: education, screening, counseling. Marriage between carriers reduced by community education program. When marriage occurs, screening and termination of affected pregnancies reduces Thalassemia Major births. A model of elimination of a genetic disorder via a combination of health education, screening and community support e.g. Tay Sachs among Ashkenazi Jews.
Community Wide Programs for Prevention of Birth Defects and Genetic Disorders Iodization of salt prevents IDD brain damage; effective enforcement and monitoring Folic acid fortified flour reduces neural tube defects Rubella immunization before pregnancy prevents congenital rubella syndrome (CRS) Px and Rx of STDs prevents congenital syphilis, gonorrhoea, CMV and HIV infections Hep B immunization prevents maternal-fetal transmission HIV antiretroviral Rx protects newborn, breast fed baby
Prenatal Prevention Cessation of smoking, alcohol and drug intake Pre-pregnancy and pregnancy nutrition counseling to promote optimal fetal development Genetic counseling for parents at risk, e.g. consanguineous marriages Avoid unnecessary medication Iron, folic acid and multivitamin supplements (and iodine if salt not fortified) Risk assessment and referral to high risk care program e.g. ultra sound and amniocentesis
Toxic Causes • Heavy metals • Thalidomide • Anti-epileptics • Crack babies • Fetal alcohol syndrome (FAS) • Smoking
Genetic Disorders • Transmission from one parent (dominant) • Huntington’s chorea • Transmission from both parents (recessive) • Thalassemia • Sickle cell
Cerebral Palsy (CP) Group of neurological disorders occurring in about 1/400 births, causing motor disabilities Associated with mental retardation, seizure disorders, motor spasticity or sensory problems. Rel to low birth weight (<2,500 grams), especially very LBW (<1,500 grams) Intracranial hemorrhage, Rh incompatibility, intra-uterine and birth trauma, maternal exposure to heavy metals such as mercury, and other unidentified factors (?HDN) Some 20% due to intrauterine fetal hypoxia
Cystic Fibrosis (CF) • Commonest lethal genetic disease in the US white population, in 1/2,000 live births (1/3000 in Canadian study) • Recessive gene present in 5% of the white population and 2% of blacks in the US • Causes production of abnormally thick mucus in the lungs, intestines and other glands, • Chronic obstructive lung disease, repeated infections, and destruction of lung tissue. • Frequent hospitalization and death, even with best of care, by age 30 (median age of death is 24)
Cystic Fibrosis Prevention • Prenatal screening with chorionic villus sampling or amniocentesis. • Screening pregnancies with a previous CF birth can prevent a second CF child, but general population screening is not yet available. • Early diagnosis, support and education of parents can improve the duration and quality of life of CF person. • Treatment complex, costly, multidisciplinary approach. Gene therapy techniques is becoming available to improve case management
Physiologic • Rh • Hemorrhagic Disease of Newborn • Smoking • LBW • Nutritional
Smoking Nicotine reduces placental blood flow Complications- premature delivery Pregnant smokers eat more but babies weigh less LBW causes 300,000 deaths in US annually Nicotine found in breast milk Smoking associated with SIDS Smokers 3-4x risk Secondary exposure 2x risk
Hemmorhagic Disease of Newborn (HDN) • Physiologic deficiency of prothrombin • Common – early and late (at 1-2, and 2-12 weeks) • High risk in LBW and breast fed babies • Vitamin K since 1950s • Controversies in Europe in 1990s • Reconfirmed as routine prophylaxis e.g. NY State • Vital in routine infant care - mandatory American Academy of Pediatrics, Committee of Nutrition. Pediatrics. 1961 American Academy of Pediatrics, Committee of Nutrition. Pediatrics. 2003
Israel Experience HDN • Vitamin K widely used and increasing , but far from universal practice in the 1970s • In 1977, HDN deaths in Israel were 131/100,000 live births; declined to 31/100,000 live births in 1984 and 3/100,000 in 1988 • In 1984, vitamin K made mandatory for newborn care by the Ministry of Health • Subsequent large decline in deaths from intra-cranial and intra-ventricular hemorrhage, may be partly due to routine use of vitamin K Israel Ministry of Health
New York State HDN Review • We reviewed vital statistics in New York State finding infant deaths and hospitalizations attributed to neonatal hemorrhagic conditions • Case record reviews showed absence of recorded giving vitamin K in 65% of deaths; others given after bleeding began • Vitamin K not included in standing orders in any of 22 hospitals contacted • Review led to vitamin K being made a mandatory newborn care procedure in NY State Public Health Code Tulchinsky TH, et al. Am J Public Health, 1993;83:1166-1168
Primary HDN • Often fatal condition • Diffuse hemorrhage in otherwise healthy infant • During the first week of life • Particularly in low birth weight babies • Results of low levels of prothrombin and other vitamin K dependent clotting factors, (Factors II, VII, IX and X) caused by vitamin K deficiency • An exaggerated of physiologic deficiency of clotting factors normal in the first few days of life • Incidence between 2.5 to 17.0 per thousand newborns not given vitamin K prophylactically
Late HDN • Between 2-12 weeks of life, • Primarily in breast-fed babies without, or inadequate, or late vitamin K • Immaturity of liver affects production of clotting factors • Late HDN rates of 4.4-7.2/100,000 live births • Increasing reports in developing countries e.g. India
Intracranial Hemorrhage in Late HDN • Infants (n = 42) present with late HDN, 1998-2001 • Most (76%) in the age group of 1-3 months. • All term babies on exclusive breast-feeding and none received vitamin K at birth • 71% patients presented with intracranial hemorrhage, commonest site - intracerebral and multiple ICH. External bleeding in 1/3 of patients only; 3 died • Late HDN important in developing countries where vitamin K prophylaxis is not routinely practiced. • Isolated intracranial hemorrhage is a common mode of presentation. Pooni PA, Singh D, Singh H, Jain BK Indian Pediatr. 2003 Mar;40(3):243-8.
Micro Nutrient Deficiency (MND) • Iron deficiency and anemia • Iodine deficiency – cretinism • Low birth weight • Vitamin B deficiency - beriberi • Folic acid deficiency • NTDs reduced by 70% • Down’s • Congenital heart conditions
Neural Tube Defects (NTDs) Defects of neural tube - brain, spinal cord. Range of abnormalities, from anencephaly, a markedly defective development of the brain to spina bifida, defective closure of spinal column. NTDs vary in degree of severity but many require extensive surgical and medical care. NTDs occur in 2/1,000 births in North America, but incidence is declining due to screening in pregnancy and primary prevention through folic acid pre-pregnancy and in early pregnancy.
Preventing NTDs • Screening for NTDs since early 1970s with amniocentesis, later in blood tests for alpha feto-proteins (AFP) and ultra sound • In 1980s, UK MSC showed that folic acid before pregnancy greatly reduces the chance of NTDs. • Pre-pregnancy compliance with recommended folic acid supplement in US was + 30% • Fortification of flour with FA adopted by US FDA, Canada, Chile for primary prevention of NTDs with supplements for planned pregnancies to assure 100% RDA intake • FA supplementation but not fortification in Europe
Preventive Measures for CP • Reduce low birth weight by improving maternal nutrition, smoking cessation during pregnancy • Improve prenatal care and labor/delivery • Vitamin K at birth • Reduce birth trauma • Professionally trained midwives reduces risk of CP • Prevention is limited by lack of identification of many causative factors
Mental Retardation Mild retardation (IQ of 50-70): perinatal and post-natal factors, including LBW or asphyxia at birth Severe retardation (IQ < 50) in 3-5 per 1,000 newborns Prevention requires well-organized prenatal, perinatal and postnatal care. Prenatal factors associated with CP and seizures More than 1/3 are due to chromosomal abnormalities e.g. Phenylketonuria, Down’s Others - congenital rubella, congenital hypothyroidism
Mental Retardation Pregnancies > 35 (role of folic and iron deficiency?) Congenital rubella and hypothyroidism Downs syndrome Maternal infections toxoplasmosis, cytomegaloviruses Late pregnancy > age 35 Pregnancy complications: toxemia, urinary tract infections and anemia increase risk of retardation Prenatal diagnosis, amniocentesis in pregnant women over age 35 and termination of affected pregnancies.
Newborn Screening for Congenital Disorders and Followup Management • Tay Sachs • Sickle cell disease • Thalassemia • Phenylketonuria (PKU) • Congenital hypothyroidism (CH) • Other metabolic disorders
Mandatory Screening, US Establishing Principles 1. Universal newborn screening is an essential public health responsibility critical to improve health outcomes • Development should adressed by what is in the best interest of the affected newborn, also unaffected newborns, families, health professionals, and the public • 3. NS is more than testing. It is a coordinated and comprehensive system consisting of education, screening, follow-up, diagnosis, treatment and management, and program evaluation. • 4. The medical home and the public and private components of the screening programs should be in close communication to ensure confirmation of test results and the appropriate follow-up and care of identified newborns. • 5. Recommendations about the appropriateness of conditions for newborn screening should be based on the evaluation of scientific evidence and expert opinion. • 6. specific screening programs. • 9. Total quality management should be applied to newborn screening programs. • 10. Specimens are valuable health resources for confidential storage and appropriate use of specimens. • 11. Public awareness, professional training and family education is a esponsibility that must be part of the complete newborn screening system.
Selection of Screening Conditions • Meet the following minimum criteria: • It can be identified at a phase (24-48 hours after birth) and not ordinarily be clinically detected; • A test available with appropriate sensitivity and specificity • Demonstrated benefits of early detection, timely intervention and efficacious treatment of the condition • Centralized health information data collection longitudinal assessment of disease
Choosing Conditions • Conditions chosen for evaluation included for one or more of several reasons: • Included in private, state, or national newborn screening programs; • Coincidentally revealed by some technologies used in newborn screening; • Identified by members of the expert group as worthy of consideration • Identified by disease-specific advocacy organizations; • Included in the differential diagnosis of a screening result for another condition.
Program Approach to Birth Defects • Education • Pre-pregnancy counseling • Screening and management • Nutrition, food fortification • Genetic counseling • Gov’t, UNICEF, voluntary organizations (March of Dimes)
Pre Pregnancy and Prenatal Prevention • Stop smoking, alcohol and drug intake to prevent fetal damage • STD, HIV testing • Nutrition counseling • Folic acid and iron • Genetic counseling re consanguineous marriages • Tay Sachs screening • Thalassemia and Sickle Cell screening
Pre Pregnancy and Prenatal Prevention • Avoid unnecessary medication • Physical fitness • Dental health • General counseling • Iron, folic acid, iodine, multivitamins • Pregnancy risk assessment • Referral for high risk care • Prenatal care protocol starting in T1
Priorities • Educate women, care givers • Birth Defect Registry • Review all infant and maternal deaths • Mandatory Vitamin K and eye care for all newborns • Folic acid, iron and vitamins B in flour • Iron, folic and vits B supplements during pregnancy • Smoking, alcohol cessation before, during pregnancy • Rubella eradication MMR x2 (boys and girls) • Rh management
Priorities II • Prenatal care and risk screening • Treat STIs • Screen newborns for PKU, CH, etc. • Educate and screen for thalassemia, sickle cell anemia • Hepatitis B part of routine immunization • LBW prevention – nutrition, supplements, IDA, infections • Treat maternal HIV
Birth Defects/Disorders for Primary, Secondary and Tertiary Prevention, a Program Approach • Multiple causation e.g. low birth weight, mental retardation and developmental disability (MRDD) • Toxic e.g. thalidomide, fetal alcohol syndrome, crack babies • Nutritional e.g. folic acid and NTDs, iodine and iron deficiency • Physiologic e.g. vitamin K deficiency hemorrhagic disease, Rh hemolytic anemia • Infection e.g. rubella syndrome, congenital syphilis, cytomegalovirus, HIV, gonococccal conjunctivitis • Genetic e.g. phenylketonuria, thalassemia, sickle cell disease, congenital hypothyroidism, cystic fibrosis, Down syndrome, autism, fragile X syndrome, and many others
Summary and Conclusion • Prevention of birth defects, disabilities, congenital disorders involves wide range of public health and individual care measures • Human Genome Project will increase potential • MNDs prevention cost effective • Genetic, toxic, infectious and nutritional factors all important for health of newborns • Strategic planning • Education – public and professional • Governmental, NGO and individual responsibility
References • Tulchinsky TH, Varavikova EA. The New Public Health. Academic Press, San Diego, 2000, chapter 6 • American Academy of Pediatrics. Serving the family from birth to the medical home. A report form the Newborn Screening Task Force, Washington DC, May 1999. Pediatrics. 2000;106:S391-3. • Bailey DB, Skinner D, Waren SF. Newborn screening for developmental disabilities: reframing presumptive benefits. Am J Public Health. 2005;95:1889-93. • http://mchb.hrsa.gov/screening/summary.htm
CDC. Economic costs of birth defects and cerebral palsy---United States, 1992. MMWR 1995;44:694--9. • CDC. Spina bifida and anencephaly before and after folic acid mandate---United States, 1995--1996 and 1999--2000. MMWR 2004;53:362--5. • Centers for Disease Control. Improved National Prevalence Estimates for 18 Selected Major Birth Defects, United States, 1999—2001. MMWR Weekly 2006; 54:pps. • Waitzman NJ, Romano PS, Scheffler RM. Estimates of the economic costs of birth defects. Inquiry 1994;31:188-205. • Centers for Disease Control. Improved National Prevalence Estimates for 18 Selected Major Birth Defects --- United States, 1999—2001. MMWR. 2006;54(51&52);1301-05.