Substantial Weight Gain in Adulthood Is Associated with Lower Probability of Live Birth Following Assisted Reproduction

BMI status and weight trajectories across females' reproductive years and risk of adverse pregnancy outcomes: a prospective cohort study

BACKGROUND

Prepregnancy body mass index (BMI) is a well-established risk factor of adverse pregnancy outcomes (APOs). The associations of long-term and short-term weight trajectories with APOs are less clear.

OBJECTIVES

This study aimed to determine the associations of weight trajectories during females' reproductive years, before and between pregnancies, with risk of APOs.

METHODS

We followed 16,241 females (25,386 singleton pregnancies) participating in a prospective cohort, the Nurses' Health Study II. Weight at age 18 y, current weight, and height were assessed at baseline (1989), and weight was updated biennially. Pregnancy history was self-reported in 2009. The primary outcome was a composite of hypertensive disorders of pregnancy (HDP), gestational diabetes (GDM), preterm birth, and stillbirth. Secondary outcomes were individual APOs. The associations of weight change with APOs were estimated using log-binomial regression, adjusting for demographic, lifestyle, reproductive factors, and baseline BMI (in kg/m2).

RESULTS

The mean (standard deviation [SD]) age at first in-study pregnancy was 33.7 (4.1) y. The mean (SD) time from age 18 y to pregnancy, baseline to pregnancy, and between pregnancies was 16.3 (4.0), 6.1 (3.0), and 2.9 (1.6) y, with a corresponding weight change of 6.4 (9.1), 3.1 (5.8), and 2.3 (4.8) kg, respectively. Of the pregnancies, 4628 (18.2%) were complicated by ≥1 APOs. Absolute weight change since age 18 y was most strongly associated with APOs. Compared with females whose weight remained stable (0-2 kg) since age 18, females who gained >2 kg had higher risk of APO (2.1-9.9 kg, relative risk [RR]: 1.12; 95% confidence interval [CI]: 1.02, 1.23; 10.0-14.9 kg, RR: 1.43; 95% CI: 1.29, 1.60; ≥15 kg, RR: 1.87; 95% CI: 1.69, 2.08), primarily driven by HDP and GDM. The associations of per 1 kg weight gain before and between pregnancies with HDP were nearly identical.

CONCLUSIONS

Weight trajectories prior to and between pregnancies were associated with the risk of APOs, particularly HDP. Longer periods of weight gain, corresponding to greater absolute weight gain, were most strongly associated with higher risk of APOs.

Zinc transporters ZIPT-2.4 and ZIPT-15 are required for normal C. elegans fecundity

PURPOSE

The requirement of zinc for the development and maturation of germ lines and reproductive systems is deeply conserved across evolution. The nematode Caenorhabditis elegans offers a tractable platform to study the complex system of distributing zinc to the germ line. We investigated several zinc importers to investigate how zinc transporters play a role in the reproductive system in nematodes, as well as establish a platform to study zinc transporter biology in germline and reproductive development.

METHODS

Previous high throughput transcriptional datasets as well as phylogenetic analysis identified several putative zinc transporters that have a function in reproduction in worms. Phenotypic analysis of CRISPR-generated knockouts and tags included characterization of offspring output, gonad development, and protein localization. Light and immunofluorescence microscopy allowed for visualization of physiological and molecular effects of zinc transporter mutations.

RESULTS

Disruption of two zinc transporters, ZIPT-2.4 and ZIPT-15, was shown to lead to defects in reproductive output. A mutation in zipt-2.4 has subtle effects on reproduction, while a mutation in zipt-15 has a clear impact on gonad and germline development that translates into a more pronounced defect in fecundity. Both transporters have germline expression, as well as additional expression in other cell types.

CONCLUSIONS

Two ZIP-family zinc transporter orthologs of human ZIP6/10 and ZIP1/2/3 proteins are important for full reproductive fecundity and participate in development of the gonad. Notably, these zinc transporters are present in gut and reproductive tissues in addition to the germ line, consistent with a complex zinc trafficking network important for reproductive success.

Ectopic Fat Depots and Cardiometabolic Burden: A Possible Dangerous Liaison in Women Planning Assisted Reproduction

Objective: We evaluated cardiometabolic burden in women planning assisted reproduction in order to identify subgroups at higher risk of pregnancy complications and cardiovascular disease. Materials and methods: In this cross-sectional study we investigated 60 infertile women with BMI≥25 kg/m2 referred to the Center for Assisted Reproduction. All women underwent metabolic, anthropometric parameters and ultrasound evaluation of ectopic fat depots. Results: All women had waist ≥80 cm. We found that 93.3% of women had pathological subcutaneous, 58.3% visceral and 80% para-perirenal fat; all women had fatty liver. Visceral fat and severity of steatosis were significantly related to the presence of metabolic syndrome (OR =5.7; p=0.03).A significant negative correlation between low HDL-c and para-perirenal fat (p<0.0001), a significant positive correlation with fasting plasma glucose and para-perirenal fat (p=0.001) were found. We observed a significant positive correlation between visceral fat and hs-CRP (p=0.002), HOMA-IR (p=0.04) and triglycerides (p=0.002), a significant negative correlation with HDL-c (p=0.05). Conclusion: This study by highlighting a clinically "dangerous liaison" between ectopic fat depots and metabolic/inflammatory markers, might permit to identify women with a worse metabolic phenotype and encourage lifestyle changes for improving their general and reproductive health together.