TH Tulchinsky MD MPH

Braun School Public Health

8 Jan 2006

Prevention of Birth Defects and Disabilities

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

PhysiologicLBWHDN

NutritionalIodine and iron

deficiencyFolic acid deficiency

InfectiousRubella syndromeSTIs – Syphilis, GC, HIVCMV

Unknown Cerebral palsy

ToxicFASSmoking, alcohol, drugs

GeneticPKUCHThalassemia, Sickle CellTay Sachs etc

Injury

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

Maternal-Fetal Infectious Transmission

• GC conjunctivitis• Syphilis• TB• Syphilis• Cytomegalovirus• HIV/AIDS

• Congenital rubella• Mumps• Toxoplasmosis• Vaginitis

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 monitoringFolic 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 infectionsHep B immunization prevents maternal-fetal transmissionHIV antiretroviral Rx protects newborn, breast fed baby

Prenatal Prevention

Cessation of smoking, alcohol and drug intakePre-pregnancy and pregnancy nutrition counseling to promote optimal fetal developmentGenetic counseling for parents at risk, e.g. consanguineous marriages Avoid unnecessary medicationIron, 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. 2003

American Academy of Pediatrics, Committee of Nutrition.

Pediatrics. 1961

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 BKIndian 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 seizuresMore than 1/3 are due to chromosomal abnormalities e.g.

Phenylketonuria, Down’sOthers - congenital rubella, congenital hypothyroidism

Mental Retardation

Pregnancies > 35 (role of folic and iron deficiency?) Congenital rubella and hypothyroidism Downs syndromeMaternal infections toxoplasmosis, cytomegaloviruses Late pregnancy > age 35Pregnancy complications: toxemia, urinary tract infections and anemia increase risk of retardationPrenatal 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

Objective Healthy Children

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.