The association between major birth defects and preterm birth.

OBJECTIVE: To evaluate the association between preterm birth and major birth defects by maternal and infant characteristics and specific types of birth defects. STUDY DESIGN: We pooled data for 1995-2000 from 13 states with population-based birth defects surveillance systems, representing about 30% of all U.S. births. Analyses were limited to singleton, live births from 24-44 weeks gestational age. RESULTS: Overall, birth defects were more than twice as common among preterm births (24-36 weeks) compared with term births (37-41 weeks gestation) (prevalence ratio [PR] = 2.65, 95% confidence interval [CI] 2.62-2.68), and approximately 8% of preterm births had a birth defect. Birth defects were over five times more likely among very preterm births (24-31 weeks gestation) compared with term births (PR = 5.25, 95% CI 5.15-5.35), with about 16% of very preterm births having a birth defect. Defects most strongly associated with very preterm birth included central nervous system defects (PR = 16.23, 95% CI 15.49-17.00) and cardiovascular defects (PR = 9.29, 95% CI 9.03-9.56). CONCLUSIONS: Birth defects contribute to the occurrence of preterm birth. Research to identify shared causal pathways and risk factors could suggest appropriate interventions to reduce both preterm birth and birth defects.

Folk and traditional medicine use by a subset of Hispanic adolescents.

UNLABELLED: Rates of Folk and Traditional Medicine (FTM) use are high among Hispanic adults. No data have been published on FTM use among the rapidly growing Hispanic adolescent population. OBJECTIVES: To determine the prevalence of and personal factors associated with FTM use among Mexican-American adolescents. STUDY GROUP: 182 Mexican-American adolescents (14-19 years) from community-based organizations. METHODS: We conducted a cross-sectional survey using a self-report instrument available in English and Spanish. RESULTS: In the past year, 49 (26.9%) subjects reported FTM use, all prompted by illness: 43 (23.6%) used herbal remedies, and 8 (4.4%) used traditional healers. Five subjects reported using dangerous herbs. Among herbal users, 56.3% did not disclose FTM use to medical providers, largely due to the providers' lack of inquiry. Logistic regression comparing herbal users with non-FTM users found subjects dissatisfied with their most recent medical visit (AOR = 10.6; 95% CI = 2.8-40.7) and subjects endorsing family FTM use (AOR = 8.4; 95% CI = 4.0-30.2) were more likely to use herbal remedies. Acculturation, insurance status, socioeconomic status, and having a personal healthcare provider were not related to herbal use. CONCLUSIONS: The use of practitioner-based FTM modalities was rare among this convenience sample of Mexican-American adolescents. Self-treatment with herbal use was common; harmful herbs were used infrequently. Access to care does not appear to motivate herb use. The high rates of herb use by dissatisfied patients, paired with high rates of non-disclosure and lack of provider inquiry, suggests that efforts to provide more culturally sensitive care, including routine inquiry about FTM use in Mexican-American adolescents, are needed. Patterns of complimentary and alternative medicine (CAM)/FTM use vary between age and ethnic cohorts.

Descriptive epidemiologic features shared by birth defects thought to be related to vascular disruption in Texas, 1996-2002.

BACKGROUND: In utero vascular disruptions are thought to be associated with a variety of birth defects. This study examined the descriptive epidemiology of several of those defects using data from a large birth defects registry. METHODS: Data on birth defects ascertained from pregnancies in 1996-2002 were obtained from the Texas Birth Defects Registry. Using Poisson regression, we calculated crude and adjusted associations between maternal and infant characteristics and birth defects thought to be related to vascular disruption. We repeated the analysis using isolated cases and cases occurring in mothers <20 years. RESULTS: The most commonly shared pattern was observed for plurality and five defects: large intestinal atresia (PR 3.67; CI: 1.63-7.13), renal agenesis (PR 2.05; CI: 1.55-2.65), transverse limb deficiency (PR 1.85; CI: 1.28-2.57), porencephaly (PR 5.18; CI: 2.40-9.87), and Goldenhar syndrome (PR 3.45; CI: 1.04-8.53). Hispanics had the highest prevalence of gastroschisis (PR 1.21; CI: 1.05-1.40), transverse limb deficiency (PR 1.19; CI: 1.01-1.40), microtia/anotia (PR 2.22; CI: 1.83-2.70), and Poland anomaly (PR 1.90; CI: 1.26-2.93). Male infants were at greatest risk for renal agenesis (PR 1.58; CI: 1.40-1.80), porencephaly (PR 1.66; CI: 1.03-2.72), and Poland anomaly (PR 1.52; CI: 1.05-2.21). CONCLUSIONS: Our study confirmed findings in previous studies, but also uncovered several new associations.

Prevalence is the preferred measure of frequency of birth defects.

Researchers and other public health professionals continue to debate the use of prevalence versus incidence as the preferred term to represent the frequency of birth defects. This paper addresses this question by noting that incidence--the number of new cases of a disorder in a given at-risk population during a specified time period--cannot be reliably estimated with existing data. Consequently, it is not appropriate to use the term "incidence" in reporting the frequency of birth defects, and the term prevalence is recommended. The basis for this recommendation, and issues involved in calculating both measures, are discussed.

In utero exposure to environmental estrogens and male reproductive health: a systematic review of biological and epidemiologic evidence.

In recent years, chemicals with hormone-like properties have become a topic of scientific and public discussion. It has been hypothesized that prenatal exposure of the male fetus to endocrine disruptors may be responsible for a series of outcomes, such as hypospadias and cryptorchidism. The purpose of this study was to review the endocrine disruption hypothesis, to present the relevant supporting evidence, to summarize the current knowledge, to identify gaps and limitations in the interpretation of published data, and to define future directions in research. An update on environmental estrogens was followed by an assessment of the biological plausibility and evidence connecting the environmental chemicalization with adverse reproductive outcomes in males. Subsequently, we carried out a systematic review of human studies attempting to document a direct effect of exogenous estrogens on the male reproductive system. The results do not support with certainty the view that environmental estrogens contribute to an increase in male reproductive disorders, neither do they provide sufficient grounds to reject such a hypothesis.

Birth defects risk associated with maternal sport fish consumption: potential effect modification by sex of offspring.

Contaminated sport fish consumption may result in exposure to various reproductive and developmental toxicants, including pesticides and other suspected endocrine disruptors. We investigated the relation between maternal sport fish meals and risk of major birth defects among infants born to members of the New York State (NYS) Angler Cohort between 1986 and 1991 (n=2237 births). Birth defects (n=125 cases) were ascertained from both newborn medical records and the NYS Congenital Malformations Registry. For sport fish meals eaten during pregnancy, the odds ratio (OR) for all major malformations combined was slightly elevated for < or =1 meal/month (OR=1.26, 95% confidence interval (CI): 0.84, 1.89) and > or =2 meals/month (OR=1.51, CI=0.74, 3.09), with no meals during pregnancy as the reference category. Higher ORs were consistently observed among male offspring compared with females. For > or =2 meals/month, the risk for males was significantly elevated (males: OR=3.01, CI: 1.2, 7.5; females: OR=0.73, CI: 0.2, 2.4). Exposure during pregnancy and effect modification by infants sex could be important considerations for future studies of birth outcomes associated with endocrine disruptors.

Occupational exposure to glycol ethers and human congenital malformations.

OBJECTIVES: This commentary reviews toxicological information and critically evaluates epidemiological information on the relationship between glycol ethers and congenital malformations. METHODS: The authors identified and assessed toxicological and epidemiological research on glycol ethers used in occupational settings and congenital malformations. Sensitivity analyses evaluated the possible role of methodological problems in explaining the findings of the epidemiological studies. RESULTS: Exposure to certain glycol ethers, including ethylene glycol monomethyl ether and ethylene glycol mono-ethyl ether, throughout the period of major organogenesis, has induced malformations of many organ systems in some of the animal models studied. Other glycol ethers, including ethylene glycol butyl and propyl ethers and most propylene glycol ethers, have not induced fetal malformations in the animal models studied. Four epidemiological studies have assessed the relationship between occupational exposure to glycol ethers and congenital malformations in humans. One study was uninformative because of small numbers, two found a positive association between glycol ethers and malformations of a number of different organs, and one found no association with neural-tube defects. Sensitivity analyses indicated that the results of the latter three investigations could be due to methodological problems. The positive studies, further, lack biological plausibility, in that the glycol ethers to which the subjects were exposed have not been, for the most part, teratogenic in the animal models that have been studied. CONCLUSIONS: The current evidence is insufficient for one to determine whether occupational exposure to glycol ethers causes human congenital malformations. We suggest that future studies quantify the effect of methodological problems on study results, using methods such as validation studies and sensitivity analysis.

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.