Differential effects of cigarette smoking on birth weight by maternal body mass index

Association of leptin receptor expression in placenta and peripheral blood mononuclear cell with maternal weight in birth outcomes

INTRODUCTION

The pregnancy period represents the most intense period of growth and development. Pre-pregnancy weight influences weight gain during pregnancy. Leptin is a hormone mainly derived from white adipose tissue, during pregnancy leptin is also produced by the placenta. It has been suggested that the effects of placental leptin on the mother may contribute to endocrine-mediated alterations in energy balance; a dysregulation in leptin levels or its receptors may lead to poor birth outcomes. Therefore, the main goal of the present study was to analyze the differences in birth outcomes by maternal weight with the expression level of leptin receptor in maternal peripheral blood mononuclear cell (PBMC) and placental tissue.

METHODS

Women with full-term gestation and its offspring were enrolled. Total RNA from maternal PBMC and placenta was obtained to perform the analysis of expression of the leptin receptor (LEPR) gene trough real-time PCR technique. Data were analyzed using one-way ANOVA or Mann-Whitney u test when applicable. Pearson correlation coefficient was used to determine the relationship between continuous variables (Stata v.13); p ≤ 0.05 was considered statistically significant.

RESULTS

No statistically significant differences were found between LEPR expression level and the BMI studied groups in maternal PBMC and placental tissue. Interaction between gestational weight gain (GWG) and LEPR in maternal PBMC explain in a 32% the variability of the newborn weight.

CONCLUSIONS

LEPR expression level in maternal PBMC correlates with newborn measurements independent from sex. GWG can affect fetal development by increasing fetal birth weight.

Smoking and Smoking Cessation in the Risk for Fetal Growth Restriction and Low Birth Weight and Additive Effect of Maternal Obesity

Many studies have shown that neonates of smoking mothers have a lower birth weight, but several issues remain poorly studied, e.g., the effects of giving up smoking or the combined effects of smoking and maternal obesity. Therefore, we evaluated a prospective cohort of 912 mothers in a single pregnancy, recruited in Poland, in 2015−2016. In the cohort, we recorded 72 (7.9%) newborns with birth weight <10th percentile, 21 (2.3%) fetal growth restriction (FGR) cases, and 60 (6.6%) low birth weight (LBW, <2500 g) newborns. In the cohort, 168 (18.4%) women smoked before pregnancy; the mean number of cigarettes/day was 10.8 (1–30), and the mean number of years of cigarette smoking was 8.5 (1–25). Among smokers, 57 (6.3%) women smoked in the first trimester. Adjusted odds ratio (AOR) of newborn outcomes (with 95% confidence intervals, CI) was calculated in multi-dimensional logistic regressions. Compared to participants who had never smoked, smoking before pregnancy was associated with a higher odds ratio of birth weight <10th percentile (AOR = 1.93, CI: 1.08–3.44, p = 0.027), but the result for LBW (AOR = 2.76, CI: 1.05–7.26, p = 0.039) and FGR (AOR = 1.13, CI: 0.38–3.36, p = 0.822) had the wider confidence interval or was insignificant. Effects of smoking cessation before pregnancy were statistically insignificant for the studied outcomes. Smoking in the first trimester was associated with a higher risk of birth weight <10th percentile (AOR = 4.68, CI: 2.28–9.62, p < 0.001), LBW (AOR = 6.42, CI: 1.84–22.36, p = 0.004), and FGR (AOR = 3.60, CI: 0.96–13.49, p = 0.057). Smoking cessation in the second/third trimester was associated with a higher odds ratio of birth weight <10th percentile (AOR = 4.54, CI: 1.58–13.02, p = 0.005), FGR (AOR = 3.36, CI: 0.6–18.74, p = 0.167), and LBW (AOR = 2.14, CI: 0.62–7.36), p = 0.229), to a similar degree to smoking in the first trimester. The odds ratios were higher in the subgroup of pre-pregnancy body mass index ≥25 kg/m² for the risk of birth weight <10th percentile (AOR = 6.39, CI: 2.01–20.34, p = 0.002) and FGR (AOR = 6.25, CI: 0.86–45.59, p = 0.071). The length of cigarette smoking time was also the risk factor for studied outcomes. Conclusions: Smoking in the first trimester increased the studied risks, and the coexistence of excessive maternal weight increased the effects. Smoking cessation during the second/third trimester did not have a protective effect.

Maternal sociodemographic and health behaviours associated with adiposity in infants as measured by air displacement plethysmography

BACKGROUND

Identifying modifiable factors associated with body fat in infancy may improve health outcomes. Few studies have examined factors associated with percentage body fat calculated using air displacement plethysmography, a gold standard technique.

AIMS

To investigate maternal sociodemographic and health behaviour characteristics associated with percentage body fat in offspring at birth.

STUDY DESIGN

Observational cross-sectional study in which the body composition of term infants was measured by air displacement plethysmography during the hospital stay after birth.

SUBJECTS

One-hundred-and-ninety-six women and their term (37-42 weeks) infants.

OUTCOME MEASURES

Associations between infant body composition and maternal sociodemographic and health characteristics.

RESULTS

One-hundred-and-ninety-six women (41.8% primiparous) participated. Mean percentage body fat among infants (51.5% female) was 10.3 ± 3.7. Percentage body fat was significantly (p < 0.001) higher in infants born to women with an obese or overweight body mass index (BMI), when compared to infants born to women with a healthy BMI (12.1 ± 4.0, 11.1 ± 3.1, and 9.2 ± 3.7, respectively). A significant positive correlation (r = 0.294) was observed, with the percentage body fat of infants born to women with an overweight or obese BMI being 17.1% and 23.9% higher, respectively, than that of infants born to women with a healthy weight BMI. Percentage body fat was lower in infants born to primiparous women (p = 0.011) and women of low social class (p = 0.003).

CONCLUSIONS

Infants born to women with an overweight or obese pre-pregnancy BMI had significantly higher mean percentage body fat when compared to infants born to women with a healthy pre-pregnancy BMI. Research into approaches that promote a healthy BMI in advance of pregnancy is warranted.

Exercise alters mouse sperm small noncoding RNAs and induces a transgenerational modification of male offspring conditioned fear and anxiety

There is growing evidence that the preconceptual lifestyle and other environmental exposures of a father can significantly alter the physiological and behavioral phenotypes of their children. We and others have shown that paternal preconception stress, regardless of whether the stress was experienced during early-life or adulthood, results in offspring with altered anxiety and depression-related behaviors, attributed to hypothalamic-pituitary-adrenal axis dysregulation. The transgenerational response to paternal preconceptual stress is believed to be mediated by sperm-borne small noncoding RNAs, specifically microRNAs. As physical activity confers physical and mental health benefits for the individual, we used a model of voluntary wheel-running and investigated the transgenerational response to paternal exercise. We found that male offspring of runners had suppressed reinstatement of juvenile fear memory, and reduced anxiety in the light-dark apparatus during adulthood. No changes in these affective behaviors were observed in female offspring. We were surprised to find that running had a limited impact on sperm-borne microRNAs. The levels of three unique microRNAs (miR-19b, miR-455 and miR-133a) were found to be altered in the sperm of runners. In addition, we discovered that the levels of two species of tRNA-derived RNAs (tDRs)-tRNA-Gly and tRNA-Pro-were also altered by running. Taken together, we believe this is the first evidence that paternal exercise is associated with an anxiolytic behavioral phenotype of male offspring and altered levels of small noncoding RNAs in sperm. These small noncoding RNAs are known to have an impact on post-transcriptional gene regulation and can thus change the developmental trajectory of offspring brains and associated affective behaviors.