Maternal smoking behaviour across the first two pregnancies and small for gestational age birth: Analysis of the SLOPE (Studying Lifecourse Obesity PrEdictors) population-based cohort in the South of England.

Maternal smoking is established to cause adverse birth outcomes, but evidence considering maternal smoking change across successive pregnancies is sparse. We examined the association between self-reported maternal smoking during and between the first two pregnancies with the odds of small for gestational age (SGA) birth (<10th percentile) in the second infant. Records for the first two pregnancies for 16791 women within the SLOPE (Studying Lifecourse Obesity PrEdictors) study were analysed. This is a population-based cohort of prospectively collected anonymised antenatal and birth healthcare data (2003-2018) in Hampshire, UK. Logistic regression was used to relate maternal smoking change to the odds of SGA birth in the second infant. In the full sample, compared to never smokers, mothers smoking at the start of the first pregnancy had higher odds of SGA birth in the second pregnancy even where they stopped smoking before the first antenatal appointment for the second pregnancy (adjusted odds ratio (aOR) 1.50 [95% confidence interval 1.10, 2.03]). If a mother was not a smoker at the first antenatal appointment for either her first or her second pregnancy, but smoked later in her first pregnancy or between pregnancies, there was no evidence of increased risk of SGA birth in the second pregnancy compared to never smokers. A mother who smoked ten or more cigarettes a day at the start of both of her first two pregnancies had the highest odds of SGA birth (3.54 [2.55, 4.92]). Women who were not smoking at the start of the first pregnancy but who subsequently resumed/began smoking and smoked at the start of their second pregnancy, also had higher odds (2.11 [1.51, 2.95]) than never smokers. Smoking in the first pregnancy was associated with SGA birth in the second pregnancy, even if the mother quit by the confirmation of her second pregnancy.

Anti-Müllerian hormone and lifestyle, reproductive, and environmental factors among women in rural South Africa.

BACKGROUND: Few data exist regarding anti-Müllerian hormone, a marker of ovarian reserve, in relation to environmental factors with potential ovarian toxicity. METHODS: This analysis included 420 women from Limpopo, South Africa studied in 2010-2011. Women were administered comprehensive questionnaires, and plasma concentrations of anti-Müllerian hormone and dichlorodiphenyltrichloroethane were determined. We used separate multivariable models to examine the associations between natural log-transformed anti-Müllerian hormone concentration (ng/ml) and each of the lifestyle, reproductive, and environmental factors of interest, adjusted for age, body mass index, education, and parity. RESULTS: The median age of women was 24 years (interquartile range [IQR] = 22 to 26); the median anti-Müllerian hormone concentration was 3.1 ng/ml (IQR = 2.0 to 6.0). Women who reported indoor residual spraying in homes with painted walls (indicative of exposure to pyrethroids) had 25% lower (95% confidence interval [CI] = -39%, -8%) anti-Müllerian hormone concentrations compared with women who reported no spraying. Little evidence of decreased anti-Müllerian hormone concentrations was observed among women with the highest dichlorodiphenyltrichloroethane levels. Compared with women who used an electric stove, no association was observed among women who cooked indoors over open wood fires. The findings also suggested lower anti-Müllerian hormone concentrations among women who drank coffee (-19% [95% CI = -31%, -5%]) or alcohol (-21% [95% CI = -36%, -3%]). CONCLUSIONS: These are among the first data regarding anti-Müllerian hormone concentrations relative to pesticides and indoor air pollution. Our results are suggestive of decreased ovarian reserve associated with exposure to pyrethroid pesticides, which is consistent with laboratory animal data.

Effects of perfluorooctanoic acid (PFOA) exposure to pregnant mice on reproduction.

Perfluorooctanoic acid (PFOA) has similar characteristics to perfluorooctane sulfonate (PFOS) in reproduction toxicity featured by neonatal death. We found that PFOS exposure to mice during pregnancy led to intracranial blood vessel dilatation of fetuses accompanied by severe lung collapse which caused neonatal mortality. Thus, we adopted the corresponding experimental design to PFOS in order to characterize the neonatal death by PFOA. Pregnant ICR mice were given 1, 5 and 10 mg/kg PFOA daily by gavage from gestational day (GD) 0 to 17 and 18 for prenatal and postnatal evaluations, respectively. Five to nine dams per group were sacrificed on GD 18 for prenatal evaluation; other 10 dams were left to give birth. No maternal death was observed. The liver weight increased dose-dependently, with hepatocellular hypertrophy, necrosis, increased mitosis and mild calcification at 10 mg/kg. PFOA at 10 mg/kg increased serum enzyme activities (GGT, ALT, AST and ALP) with hypoproteinemia and hypolipidemia. PFOA treatment reduced the fetal body weight at 5 and 10 mg/kg. Teratological evaluation showed delayed ossification of the sternum and phalanges and delayed eruption of incisors at 10 mg/kg, but did not show intracranial blood vessel dilatation. Postnatal evaluation revealed that PFOA reduced the neonatal survival rate at 5 and 10 mg/kg. At 5 mg/kg pups were born alive and active and 16% died within 4 days observation, while all died within 6 hr after birth at 10 mg/kg without showing intracranial blood vessel dilatation. The cause of neonatal death by PFOA may be different from PFOS.

Induction of labour with oral misoprostol for prelabour rupture of membranes at term.

OBJECTIVE: To study the efficacy, safety and maternal satisfaction of oral misoprostol for induction of labour in patients with prelabour rupture of membrane at term (PROM). METHODS: Pregnant women with singleton pregnancy at term with cephalic presentation with prelabour rupture of membranes having no other obstetric and maternal contraindications for induction of labour, were included in the study. Patients were given 50ugm of oral misoprostol at six hourly intervals for a total of three doses or until labour was established. RESULTS: Of the 104 patients included in the study, 28 (26.9%) were primigraivda and 72.1% were multigravida. Induction delivery internal was shorter in multigravida and longer in primigraivda. Patients with Bishop score of less than 5 had a longer induction delivery interval as compared to patients with Bishop score more than 5. Significant side effects included nausea and vomiting in 68 patients (65.3%). Vaginal delivery was achieved in 80.7% with Cesarean section in 19.2% of patients. Neonatal outcome was good with no stillbirths and only two neonatal deaths. A large number, 98 (94.2%) of women were satisfied with induction of labour with oral misoprostol in PROM. CONCLUSION: Active management with oral misoprostol resulted in more women going into labour and delivering within 24 hours of PROM with no significant maternal and neonatal complications.

Disinhibition of maternal behavior following neurotoxic lesions of the hypothalamus in primigravid rats.

Virgin female rats do not respond maternally to foster pups due to an endogenous neural circuit that actively inhibits the display of maternal behavior. Once pregnant, primigravid rats will continue to avoid foster pups until just prior to or at parturition. Anosmia or lesions of the olfactory tract, medial amygdala, and areas of the hypothalamus will stimulate virgin females to display maternal behavior rapidly, but little is known of the effect of these lesions in primigravid rats. The objective of the present study was to determine if neurotoxic lesions of the dorsomedial (DMH) and ventromedial nuclei (VMH) of the hypothalamus will advance the onset of maternal behavior in primigravid rats. Nulliparous Sprague-Dawley female rats were mated and then on day 8 of gestation bilaterally infused with N-methyl-d-aspartic acid (NMDA; 8 microg/0.2 microl/side) or vehicle directed toward either the DMH or VMH. Beginning on day 15 of gestation until parturition, females were tested daily for maternal responsiveness. DMH and VMH lesions significantly advanced the onset of maternal behavior (5-6 days vs. 0-1 day before parturition) in first-time pregnant rats. These results indicate that the DMH and VMH are involved in the regulation of maternal behavior and may be part of an endogenous neural circuit that inhibits maternal behavior during pregnancy.

Preterm labour--is bacterial vaginosis involved?

OBJECTIVE: To assess the efficacy of treatment of bacterial vaginosis (BV) using metronidazole to reduce preterm labour in primigravidae and multigravidae with previous midtrimester abortion or preterm labour. DESIGN: Randomised controlled trial. SETTING: Tertiary academic hospital. METHOD: Two different groups of patients were screened for BV at the first antenatal visit, namely primigravidae and high-risk multigravidae who had had a previous midtrimester abortion or preterm delivery. Patients where BV was diagnosed clinically or on Gram's stain of a smear taken from the posterior vaginal fornix, received either 400 mg metronidazole, or 100 mg vitamin C orally twice daily for 2 days. The Gram's stain was repeated after 4 weeks. If BV was found again, treatment with the same drug was repeated. OUTCOME MEASURES: Preterm delivery, birth weight and perinatal deaths. RESULTS: One thousand and five patients entered the study, but 40 were excluded for various reasons and 10 were lost to follow-up. There were 464 primigravidae, of whom 150 (32%) had BV. Except for the 5-minute Apgar score, no significant differences were found between primigravidae negative for BV and those who received either metronidazole or vitamin C. There were 491 high-risk multigravidae, of whom 127 (26%) had BV. The mean gestational age in the BV-negative group was 37 weeks, in contrast to 37.4 weeks in the vitamin C group and 35.6 weeks in the metronidazole group. Birth weights in these three groups were 2,752 g, 2,759 g and 2,475 g respectively, significantly less (P = 0.0109) in the metronidazole group in comparison with the BV-negative group. Delivery before 37 weeks occurred in 29% of high-risk multigravidae with no BV but in 24% of those who took vitamin C and in 43% who took metronidazole. Differences were significant between the BV-negative and metronidazole groups (P = 0.0231) and also between the metronidazole and vitamin C groups (P = 0.0274). Delivery before 28 weeks occurred in 4% of the high-risk multigravidae with no BV but in 10% of those with BV who took metronidazole. The difference was significant (P = 0.0430). Analysis for maximum likelihood estimates for preterm labour identified only previous preterm labour or midtrimester abortion as risk factors. CONCLUSION: Metronidazole does not seem to reduce the prevalence of preterm labour when given for BV before 26 weeks' gestation.

Tetrachloroethylene in drinking water and birth outcomes at the US Marine Corps Base at Camp Lejeune, North Carolina.

A study of mean birth weight, small-for-gestational-age infants, and preterm birth was conducted at the US Marine Corps Base at Camp Lejeune, North Carolina, where drinking water was contaminated with volatile organic compounds. Tetrachloroethylene (PCE) was the predominant contaminant. The authors used multiple linear and logistic regression to analyze 1968-1985 data from 11,798 birth certificates. Overall, at most weak associations were observed between PCE exposure and study outcomes. However, associations were found between PCE exposure and birth-weight outcomes for infants of older mothers and mothers with histories of fetal loss. Adjusted mean birth-weight differences between PCE-exposed and unexposed infants were -130 g (90% confidence interval (CI): -236, -23) for mothers aged 35 years or older and -104 g (90% CI: -174, -34) for mothers with two or more previous fetal losses. Adjusted odds ratios for PCE exposure and small-for-gestational-age infants were 2.1 (90% CI: 0.9, 4.9) for older mothers and 2.5 (90% CI: 1.5, 4.3) for mothers with two or more prior fetal losses. These results suggest that some fetuses may be more vulnerable than others to chemical insult.