Decline in the prevalence of spina bifida and anencephaly by race/ethnicity: 1995-2002.

OBJECTIVE: In an effort to reduce the occurrence of neural tube defects (NTDs), folic acid fortification of US enriched grain products was authorized by the Food and Drug Administration in March 1996 and required by January 1998. Fortification has been shown to result in an important decline in the prevalence of spina bifida and anencephaly in the general US population; however, fortification's impact on specific racial/ethnic groups has not been well described. We sought to characterize the decline in the prevalence of spina bifida and anencephaly among specific racial/ethnic groups during the transition to mandatory folic acid fortification in the United States. METHODS: Data from 21 population-based birth defects surveillance systems were used to examine trends in prevalence of spina bifida and anencephaly for specific racial/ethnic groups for the years 1995-2002. These years were divided into 3 periods: prefortification, optional fortification, and mandatory fortification. Race/ethnicity was defined as Hispanic, non-Hispanic white, and non-Hispanic black. Prevalence ratios were calculated for each racial/ethnic group by dividing the prevalence from the mandatory fortification period by the prevalence in the prefortification period. RESULTS: The study included data on 4468 cases of spina bifida and 2625 cases of anencephaly. The prevalence of spina bifida and anencephaly was highest among Hispanic births, followed by non-Hispanic white births, with the lowest prevalence among non-Hispanic black births. Significant declines in spina bifida and anencephaly were observed among Hispanic births and non-Hispanic white births. The prevalence ratio for non-Hispanic black births was of borderline significance for spina bifida and was not significant for anencephaly. CONCLUSIONS: The results of this study suggest that folic acid fortification is associated with significant decreases in the prevalence of spina bifida and anencephaly among non-Hispanic white and Hispanic births. The magnitude of the reduction was similar between these 2 groups and was more pronounced for spina bifida than for anencephaly. The decline in the prevalence of spina bifida and anencephaly among non-Hispanic black births did not reach statistical significance. Efforts to increase folic acid consumption for the prevention of NTDs in pregnancies among women of all races/ethnicities should be continued, and studies to identify and elucidate other risk factors for NTDs are warranted.

Prevalence of birth defects among infants of Gulf War veterans in Arkansas, Arizona, California, Georgia, Hawaii, and Iowa, 1989-1993.

BACKGROUND: Epidemiologic studies of birth defects among infants of Gulf War veterans (GWV) have been limited to military hospitals, anomalies diagnosed among newborns, or self-reported data. This study was conducted to measure the prevalence of birth defects among infants of GWVs and nondeployed veterans (NDV) in states that conducted active case ascertainment of birth defects between 1989-93. METHODS: Military records of 684,645 GWVs and 1,587,102 NDVs were electronically linked with 2,314,908 birth certficates from Arizona, Hawaii, Iowa, and selected counties of Arkansas, California, and Georgia; 11,961 GWV infants and 33,052 NDV infants were identified. Of these, 450 infants had mothers who served in the Gulf War, and 3966 had NDV mothers. RESULTS: Infants conceived postwar to male GWVs had significantly higher prevalence of tricuspid valve insufficicieny (relative risk [RR], 2.7; 95% confidence interval [CI], 1.1-6.6; p = 0.039) and aortic valve stenosis (RR, 6.0; 95% CI, 1.2-31.0; p = 0.026) compared to infants conceived postwar to NDV males. Among infants of male GWVs, aortic valve stenosis (RR, 163; 95% CI, 0.09-294; p = 0.011) and renal agenesis or hypoplasia (RR, 16.3; 95% CI, 0.09-294; p = 0.011) were significantly higher among infants conceived postwar than prewar. Hypospadias was significantly higher among infant sons conceived postwar to GWV women compared to NDV women (RR, 6.3; 95% CI, 1.5-26.3; p = 0.015). CONCLUSION: We observed a higher prevalence of tricuspid valve insufficiency, aortic valve stenosis, and renal agenesis or hypoplasia among infants conceived postwar to GWV men, and a higher prevalence of hypospadias among infants conceived postwar to female GWVs. We did not have the ability to determine if the excess was caused by inherited or environmental factors, or was due to chance because of myriad reasons, including multiple comparisons. Although the statistical power was sufficient to compare the combined birth defects prevalence, larger sample sizes were needed for less frequent individual component defects.

Orofacial cleft malformations: associations with maternal and infant characteristics in Washington State.

BACKGROUND: To characterize the prevalence of orofacial cleft malformations and investigate variations in prevalence according to maternal and infant characteristics, we analyzed a cohort of 298,138 live births delivered between 1987 and 1990 to residents of Washington State. METHODS: Infants with cleft defects were identified using a statewide, population-based birth defects registry. Information on infant and maternal characteristics was obtained from Washington State birth certificates. Multiple logistic regression analysis was used to measure the association between potential risk factors and orofacial clefts. Cleft lip with or without cleft palate (CL +/- CP) and cleft palate (CP) were analyzed separately, depending on the presence or absence of other defects. RESULTS: We identified 608 infants with cleft defects. The prevalences of isolated and non-isolated CL +/- CP were 0.87 and 0.30 per 1,000 live births, respectively. The prevalences of isolated and non-isolated CP were 0.34 and 0.54 per 1,000 live births, respectively. Compared with mothers aged 25-29 years, mothers aged < 20 years were twice as likely to have an infant with isolated CL +/- CP (RR = 2.0; 95% CI 1.3, 2.9). Compared to white mothers, black mothers were more likely to have an infant with non-isolated CL +/- CP (RR = 2.8; 95% CI 1.2, 6.6). CONCLUSIONS: The prevalences of orofacial clefts in Washington State in 1987-90 were similar to those of other states. This study is among the first to report a greater relative risk for isolated CL +/- CP among the infants of mothers < 20 years compared to older mothers.

Registry to referral: using birth defects registries to refer infants and toddlers for early intervention services.

BACKGROUND: Although many birth defect surveillance systems were developed for the primary purpose of monitoring trends and conducting epidemiologic studies, a number of programs have recognized the potential of birth defects monitoring systems for identifying and referring children who may be eligible for services. Because almost all surveillance programs maintain a registry of all children who have been diagnosed with birth defects in a particular state or other defined geographic region, registries can play an important role in identifying eligible children and providing timely referral to specialized services. METHODS: We sent electronically an 18-question survey to the Centers for Disease Control and Prevention's list of State Birth Defects Surveillance Contacts in all 50 states, the District of Columbia, and Puerto Rico. The survey queried states as to whether they had or were developing a birth defect surveillance program, the extent to which they were currently using or were considering using their program as a means of identifying and referring children for services, and if so, the manner in which referrals were made. RESULTS: We received completed surveys from all 50 states, Washington, DC, and Puerto Rico. Thirty-two of the fifty-two respondents stated that their state or entity has an operational birth defect surveillance program. Of these, 13 have implemented an identification and referral system within the surveillance program. All 16 states that were planning a surveillance program are also are planning or beginning to implement a program that would include an identification and referral system. Respondents cited lack of resources and confidentiality concerns as being the major barriers to implementing a referral system for their registry. CONCLUSIONS: For many registries, using their surveillance data for program development purposes represents a new undertaking. This trend reflects increasing recognition of the role that state-based birth defect surveillance systems can play in supporting child-find efforts for children with special needs. In the long run, this expanded focus may further enhance the public health usefulness of birth defect surveillance programs.

Prevalence of spina bifida and anencephaly during the transition to mandatory folic acid fortification in the United States.

BACKGROUND: In 1992, the United States Public Health Service recommended that all women of childbearing age consume 400 microg of folic acid daily. The Food and Drug Administration authorized the addition of synthetic folic acid to grain products in March 1996 with mandatory compliance by January 1998. The impact of these public health policies on the prevalence of neural tube defects needs to be evaluated. We sought to determine the prevalences of spina bifida and anencephaly during the transition to mandatory folic acid fortification. METHODS: Twenty-four population-based surveillance systems were used to identify 5,630 cases of spina bifida and anencephaly from 1995-99. Cases were divided into three temporal categories depending on whether neural tube development occurred before folic acid fortification (January 1995 to December 1996), during optional fortification (January 1997 to September 1998), or during mandatory fortification (October 1998 to December 1999). Prevalences for each defect were calculated for each time period. Data were also stratified by programs that did and did not ascertain prenatally diagnosed cases. RESULTS: The prevalence of spina bifida decreased 31% (prevalence ratio [PR] = 0.69, 95% confidence interval [CI] = 0.63-0.74) from the pre- to the mandatory fortification period and the prevalence of anencephaly decreased 16% (PR = 0.84, 95% CI = 0.75-0.95). Stratification by prenatal ascertainment did not alter results for spina bifida but did impact anencephaly trends. CONCLUSIONS: The decline in the prevalence of spina bifida was temporally associated with folic acid fortification of US grain supplies. The temporal association between fortification and the prevalence of anencephaly is unclear.