Outcomes in cephalic vs noncephalic presentation in the setting of preterm premature rupture of membranes.

OBJECTIVE: This study was conducted to determine whether fetal position at the time of preterm premature rupture of membranes (PPROM) diagnosis affects outcomes. STUDY DESIGN: A retrospective study was designed to assess differences in outcomes between cephalic and noncephalic presentation at PPROM diagnosis between 24 and 34 weeks' gestation. RESULTS: Five hundred sixty-six cases of PPROM were identified; 108 cases (19.1%) were noncephalic at time of PPROM diagnosis. The 2 groups were similar with regard to demographics. Although membrane rupture and delivery occurred earlier in the noncephalic group, there was no difference in latency between groups (cephalic group, 6.22 days vs noncephalic group, 7.85 days; P = .07). Noncephalic pregnancies were substantially more likely to be complicated by oligohydramnios, abruption, intrauterine fetal death, and infectious morbidity. CONCLUSION: Noncephalic presentation at the time of diagnosis of PPROM independently and significantly increases the risk of maternal complications in such affected pregnancies.

Maternal diabetes and renal agenesis/dysgenesis.

BACKGROUND: Renal agenesis and dysgenesis are potentially lethal congenital malformations affecting 2 to 5 infants per 10,000 live births annually in the United States. The low prevalence of these malformations has complicated understanding of potential risk factors. Maternal diabetes (type 1, type 2, and gestational) has been evaluated extensively as a risk factor for other congenital malformations, but only a limited number of studies have assessed the association between diabetes and renal agenesis. METHODS: We conducted a population-based case-control study of deliveries after 20 weeks gestation in Texas Health Service Region 6 (Houston/Galveston area) from January 1, 2000 to December 31, 2002. Cases of renal agenesis/dysgenesis (n = 89) were ascertained from the Texas Birth Defects Registry. Cumulative incidence sampling was used to randomly select, from birth and fetal death records, 356 controls frequency matched to cases by delivery year and vital status. Maternal diabetes and other covariates were collected from vital records. RESULTS: The odds of renal agenesis/dysgenesis were 3.1 (95% confidence interval [CI], 1.1-9.3) times greater among deliveries of mothers with diabetes compared to deliveries of mothers without diabetes, controlling for matching factors. CONCLUSIONS: Our results are consistent with prior, but limited, research identifying diabetes as a risk factor for renal agenesis/dysgenesis. While these data did not differentiate diabetes diagnoses by type, the results suggest that maternal diabetes may be associated with renal malformations. Further study is warranted.

Intrauterine tobacco exposure may alter auditory brainstem responses in newborns.

This study of tobacco exposure and auditory processes was conducted in a predominantly low-income population of 40 pregnant women and their newborns. Urinary cotinine concentrations and self-reported smoking status were obtained from the mother during the first prenatal care visit. Auditory brainstem-evoked responses (ABRs) were recorded in neonates to assess neuroelectrical activity of the auditory nerve following a sound stimulus. Infants of mothers with the highest cotinine concentrations (> 1,000 ng/ml) responded at a rate that was four times greater (hazard ratio 4.1, 95% confidence interval 1.4-11.5) than infants of non-smoking mothers (cotinine 15-1,000 ng/ml) were not observed. Enhanced ABRs may disrupt auditory processes related to speech perception, negatively affecting reading and language development during childhood. The results suggest that tobacco exposure during pregnancy may impair auditory function.

Steroid hormone levels during pregnancy and incidence of maternal breast cancer.

Previous studies evaluating pregnancy hormone levels and maternal breast cancer were limited to surrogate indicators of exposure. This study directly evaluates the association between measured serum steroid hormone levels during pregnancy and maternal risk of breast cancer. A nested case-control study was conducted to examine third-trimester serum levels of total unconjugated estradiol, estrone, estriol, and progesterone in women who were pregnant between 1959 and 1966. Cases (n = 194) were diagnosed with in situ or invasive breast cancer between 1969 and 1991. Controls (n = 374) were matched to cases by age at the time of index pregnancy, using randomized recruitment. Elevated progesterone levels were associated with a decreased incidence of breast cancer [odds ratio (OR) for progesterone > or =270 ng/ml, 0.49; 95% confidence interval (CI), 0.22-1.1] relative to those below the lowest decile. This association was stronger for cancers diagnosed at or before age 50 (OR for progesterone > or =270 ng/ml, 0.3; 95% CI, 0.1-0.9). Increased estrone levels were associated with an increased incidence overall (OR for estrone > or =18.7 ng/ml, 2.5; 95% CI, 1.0-6.2), whereas a positive association with estradiol was not observed. Too few cases occurred within 15 years of the index pregnancy to compare adequately the short- and long-term effects of pregnancy hormone exposure. When estrogen-to-progesterone ratios were evaluated, there was an indication of a modest increased incidence of breast cancer for those with high total estrogens and high estrone levels relative to progesterone. These findings suggest that pregnancy steroid hormone levels are risk factors for breast cancer.

A review of the epidemiologic evidence concerning the reproductive health effects of caffeine consumption: a 2000-2009 update.

This review of human studies of caffeine and reproductive health published between January 2000 and December 2009 serves to update the comprehensive review published by Leviton and Cowan (2002). The adverse reproductive outcomes addressed in this review include: (1) measures of subfecundity; (2) spontaneous abortion; (3) fetal death; (4) preterm birth; (5) congenital malformations; and (6) fetal growth restriction. Methodologic challenges and considerations relevant to investigations of each reproductive endpoint are summarized, followed by a brief critical review of each study. The evidence for an effect of caffeine on reproductive health and fetal development is limited by the inability to rule out plausible alternative explanations for the observed associations, namely confounding by pregnancy symptoms and smoking, and by exposure measurement error. Because of these limitations, the weight of evidence does not support a positive relationship between caffeine consumption and adverse reproductive or perinatal outcomes.

Intra- and inter-individual variability of urinary phthalate metabolite concentrations in Hmong women of reproductive age.

The reproducibility of urinary phthalate metabolite concentrations has not been well characterized in non-pregnant women of reproductive age. Our primary study objectives were to describe the distribution of urinary phthalate metabolites concentrations among a population of Hmong women of reproductive age, and to evaluate intra- and inter-individual variability of phthalate metabolite concentrations. Ten phthalate metabolites were measured in first-morning urine samples collected from 45 women and 20 of their spouses, who were members of the Fox River Environment and Diet Study cohort in Green Bay, Wisconsin. Repeated first-morning urine samples were collected and analyzed from 25 women, who provided up to three samples over approximately 1 month. Measurement variability was assessed using intraclass correlations (ICCs) and surrogate category analysis. Linear mixed models were used to evaluate the associations between participant characteristics and phthalate metabolite concentrations. Nine of the 10 phthalate metabolites were detected in >80% of all analyzed samples, of which seven were detected in all samples. As a measure of reliability, ICCs were strongest for monobenzyl phthalate (0.64) and weakest for the metabolites of di(2-ethylhexyl)phthalate (DEHP) (ranging from 0.13 to 0.22). Similarly, surrogate category analysis suggested that a single urine sample characterized an average 1-month exposure with reasonable accuracy across low, medium and high tertiles for all metabolites, except the DEHP metabolites. Geometric mean concentrations of monoethyl phthalate increased with age, but patterns by education, income, body mass index, environmental tobacco smoke or season were not observed when measures were adjusted for urinary dilution. Our results suggest that the participant characteristics assessed in this study have limited influence on inter-individual variability of phthalate metabolite concentrations. With regard to intra-individual variability, our results suggest that urinary concentrations of some phthalate metabolites are more reproducible over time and are less subjected to exposure misclassification than others (e.g., metabolites of DEHP).

Conjugated equine estrogen influence on mammographic density in postmenopausal women in a substudy of the women's health initiative randomized trial.

PURPOSE: Increased mammographic density is associated with increased breast cancer risk and reduced sensitivity of screening mammography and is related to hormone exposure. However, the effects of conjugated equine estrogens (CEEs) alone on mammographic density in diverse racial/ethnic populations are not established. We examined the effect of CEE alone on mammographic density in a subsample of the Women's Health Initiative (WHI) clinical trial participants. PATIENTS AND METHODS: In the WHI trial, women were randomly assigned to daily CEE 0.625 mg or placebo. The effect of CEE on mammographic percent density was determined over 1 and 2 years in a stratified random sample of 435 racially and ethnically diverse participants from 15 of 40 WHI clinics. RESULTS: Use of CEE resulted in mean increase in mammographic percent density of 1.6 percentage points (95% CI, 0.8 to 2.4) at year 1 compared with a mean decrease of 1.0 percentage point (95% CI, -1.7 to -0.4) in the placebo group (P < .001). The effect persisted for 2 years, with a mean increase of 1.7 percentage points (95% CI, 0.7 to 2.7) versus a mean decrease of 1.2 percentage points (95% CI, -1.8 to -0.5; P < .001) in the hormone and placebo groups, respectively. These effects were greater in women age 60 to 79 years (P = .03 for interaction across age). CONCLUSION: Use of CEE results in a modest but statistically significant increase in mammographic density that is sustained over at least a 2-year period. The clinical significance of the CEE effect on mammographic density remains to be determined.

Accuracy of fetal growth indicators as surrogate measures of steroid hormone levels during pregnancy.

This study evaluates the use of fetal growth characteristics as surrogate measures for steroid hormone exposures during pregnancy. The validity of using birth weight, birth length, ponderal index, and placental weight as indicators of pregnancy hormone exposures was assessed using third-trimester serum samples from 568 pregnant women who participated in the Child Health and Development Studies, Berkeley, California (1959-1966). The magnitude of the associations between birth characteristics and hormone concentrations was assessed using geometric means, Pearson's correlations, and linear and logistic regression. Accuracy was evaluated using sensitivity, specificity, and receiver operating characteristic curve analyses. The strongest and most consistent association observed was between birth weight and estriol levels. Despite a positive correlation (r = 0.32) and strong associations with high estriol levels (odds ratio for highest compared with lowest birth weight quartile = 6.63, 95% confidence interval: 3.20, 12.5), the predictive performance of birth weight as a proxy for estriol levels was poor (area under the receiver operating characteristic curve = 0.66, 95% confidence interval: 0.61, 0.71). Likewise, all fetal growth measures revealed little discriminatory ability as indicators of estriol, estrone, estradiol, or progesterone levels. Thus, observed associations with these surrogate measures may not be a reflection of pregnancy hormone exposure and should be interpreted with caution.