Maternal occupational exposure to polycyclic aromatic hydrocarbons and congenital heart defects among offspring in the national birth defects prevention study.

BACKGROUND: There is evidence in experimental model systems that exposure to polycyclic aromatic hydrocarbons (PAHs) results in congenital heart defects (CHDs); however, to our knowledge, this relationship has not been examined in humans. Therefore, we conducted a case-control study assessing the association between estimated maternal occupational exposure to PAHs and CHDs in offspring. METHODS: Data on CHD cases and control infants were obtained from the National Birth Defects Prevention Study for the period of 1997 to 2002. Exposure to PAHs was assigned by industrial hygienist consensus, based on self-reported maternal occupational histories from 1 month before conception through the third month of pregnancy. Logistic regression was used to evaluate the association between maternal occupational PAH exposure and specific CHD phenotypic subtypes among offspring. RESULTS: The prevalence of occupational PAH exposure was 4.0% in CHD case mothers (76/1907) and 3.6% in control mothers (104/2853). After adjusting for maternal age, race or ethnicity, education, smoking, folic acid supplementation, and study center, exposure was not associated with conotruncal defects (adjusted odds ratio [AOR], 0.98; 95% confidence interval [CI], 0.58-1.67), septal defects (AOR, 1.28; 95% CI, 0.86-1.90), or with any isolated CHD subtype. CONCLUSIONS: Our findings do not support an association between potential maternal occupational exposure to PAHs and various CHDs in a large, population-based study. For CHD phenotypic subtypes in which modest nonsignificant associations were observed, future investigations could be improved by studying populations with a higher prevalence of PAH exposure and by incorporating information on maternal and fetal genotypes related to PAH metabolism. Birth Defects Research (Part A), 2012.

Maternal occupational exposure to organic solvents during early pregnancy and risks of neural tube defects and orofacial clefts.

OBJECTIVES: Though toxicological experiments demonstrate the teratogenicity of organic solvents in animal models, epidemiologic studies have reported inconsistent results. Using data from the population-based National Birth Defects Prevention Study, the authors examined the relation between maternal occupational exposure to aromatic solvents, chlorinated solvents and Stoddard solvent during early pregnancy and neural tube defects (NTDs) and orofacial clefts (OFCs). METHODS: Cases of NTDs (anencephaly, spina bifida and encephalocoele) and OFCs (cleft lip ± cleft palate and cleft palate alone) delivered between 1997 and 2002 were identified by birth defect surveillance registries in eight states; non-malformed control infants were selected using birth certificates or hospital records. Maternal solvent exposure was estimated by industrial hygienist review of self-reported occupational histories in combination with a literature-derived exposure database. ORs and 95% CIs for the association between solvent class and each birth defect group and component phenotype were estimated using multivariable logistic regression, adjusting for maternal age, race/ethnicity, education, pre-pregnancy body mass index, folic acid supplement use and smoking. RESULTS: The prevalence of exposure to any solvent among mothers of NTD cases (n = 511), OFC cases (n = 1163) and controls (n = 2977) was 13.1%, 9.6% and 8.2%, respectively. Exposure to chlorinated solvents was associated with increased odds of NTDs (OR = 1.96, CI 1.34 to 2.87), especially spina bifida (OR = 2.26, CI 1.44 to 3.53). No solvent class was strongly associated with OFCs in these data. CONCLUSIONS: The findings suggest that maternal occupational exposure to chlorinated solvents during early pregnancy is positively associated with the prevalence of NTDs in offspring.

Changes in caffeine consumption as a signal of pregnancy.

OBJECTIVES: The purpose of this prospective study was to examine caffeine consumption and other signals of early pregnancy. STUDY DESIGN: One hundred and five pregnant, nonsmoking, coffee drinkers ages 18-40 were enrolled by the ninth week after their last menstrual period (LMP). Participants kept daily diaries of beverage and caffeine consumption and symptoms. Urine samples were collected to assess hormone metabolites. Descriptive statistics were generated. RESULTS: During the first trimester, 96% of subjects decreased or quit drinking coffee, 65% of whom reported a unique aversion to coffee. The mean daily caffeine consumption at LMP from coffee alone was 119 mg (S.D., 105), with a range 1-574 mg. There was a 59% decrease of mean daily consumption of caffeine from coffee between weeks 4 and 6, from 96 to 39 mg. The vast majority of subjects experienced nausea (98%) and appetite loss (93%); vomiting was less prevalent (54%). The most common dietary aversions included meat, coffee, spicy foods, and dairy products. Hormone metabolite patterns are reported. CONCLUSION: Signals of early pregnancy included an aversion to coffee in addition to nausea and vomiting, which resulted in decreased caffeine consumption. These symptoms often interfered with daily life and lasted beyond the first trimester for many. Consideration should be given that a decrease in caffeine consumption may be a signal for a healthy pregnancy and acting as a confounder.

Pregnancy hormone metabolite patterns, pregnancy symptoms, and coffee consumption.

Because of contradictory reports of pregnancy outcomes and coffee intake, this study was designed to determine how hormone metabolite levels, symptoms, and coffee consumption patterns are related. Eligible subjects were recruited in Cincinnati, Ohio, from 1996 to 1998, aged 18-40 years, and nonsmokers; drank at least 18 ounces (1 ounce = 29.6 ml) of coffee per week (including decaffeinated) at the last menstrual period; and were enrolled by 9 weeks from the last menstrual period. Beverage consumption and pregnancy symptoms were recorded daily. Weekly, first-morning urine samples were collected to assess human chorionic gonadotropin, estrone-3-glucuronide, and pregnanediol-3-glucuronide. A time-dependent, repeated measures analysis was performed to test several associations. Data from 92 subjects were analyzed with the following results. 1) Coffee consumption was significantly, inversely associated with weekly levels of estrone-3-glucuronide and human chorionic gonadotropin. 2) Weekly hours of nausea were significantly, directly associated with human chorionic gonadotropin and inversely with estrone-3-glucuronide and pregnanediol-3-glucuronide. 3) Weekly coffee consumption was significantly associated with vomiting but not with nausea or appetite loss. 4) Weekly levels of pregnanediol-3-glucuronide were 32.2% lower in subjects who drank at least 8 ounces of coffee/day at the last menstrual period, though above what was necessary to maintain those pregnancies. This study shows the significance of these important variables to be considered in future research.