The effect of maternal obesity and lipid profile on first-trimester serum progesterone levels

Gestational exposure to ambient fine particulate matter disrupts maternal hepatic lipid metabolism

Pregnancy is a unique physiological stage for females as well as a vulnerable period for pollutant exposure. The effect of gestational ambient fine particulate matter (PM2.5) exposure on maternal lipid metabolism during pregnancy is rarely observed, and the mechanism is unknown. In the current study, pregnant C57BL/6 mice were randomly assigned to either ambient PM2.5 or filtered air exposure chambers since gestational day (GD) 0. Meanwhile, non-pregnant female mice were housed as controls in each exposure chamber. PM2.5 exposure exerted no significant effect on body weight gain or the body composition during pregnancy. Pregnant mice exposed to PM2.5 demonstrated improved glucose tolerance, whereas non-pregnant mice showed an increased fasting blood glucose level after PM2.5 exposure with no alterations in glucose tolerance. PM2.5 exposure exerted no significant effect on total lipid content in serum during pregnancy, while an increased serum total lipid level was found in non-pregnant mice exposed to PM2.5. PM2.5 exposure had no effect on total liver lipid levels, it increased several triacylglycerol (TAG) species and total cholesterol esters (CEs) in pregnant mice but lowered a considerable amount in non-pregnant mice' livers. Furthermore, gestational exposure to PM2.5 enhanced the expression of key enzymes in fatty acid uptake, de novo lipid synthesis, and β oxidation, and inhibited molecules for lipid export in mice liver. Conversely, PM2.5 exposure upregulated proteins involved in hepatic lipolysis and lipid export in non-pregnant mice. These results suggest that the interference of PM2.5 exposure during pregnancy on the lipid metabolism, particularly the hepatic lipid metabolism, differs from that during non-pregnancy. This study provides toxicological evidence that PM2.5 exposure during pregnancy disrupts the lipid metabolism of the liver and provides a basis for protecting vulnerable populations.

Obesity and Miscarriage

Obesity affects nearly 40% of reproductive-aged women and has serious implications for women's overall and reproductive health. Women with an elevated body mass index (BMI) have higher rates of anovulation and irregular menses, lower success with fertility treatment, and significantly higher rates of pregnancy complications, such as hypertension/preeclampsia, gestational diabetes, and preterm delivery. Many studies have also shown an association between obesity and early pregnancy loss. However, the causal association between BMI and miscarriage has not been elucidated, likely due to the multifactorial effects that BMI may have on early pregnancy development. In addition, BMI as an isolated variable fails to capture other relevant confounding health risk factors, such as nutrition, physical activity, and insulin resistance. In this review, we will summarize the current literature demonstrating the association between BMI and miscarriage, highlight the research that attempts to explain the association, and finally provide data on therapeutic interventions to improve reproductive outcomes in women suffering from obesity and early pregnancy loss.