Prepregnancy Body Mass Index and Infant Outcomes by Race and Hispanic Origin: United States, 2020

This report presents data on distributions in prepregnancy body mass index, including the three classes of obesity, by maternal race and Hispanic origin for women who gave birth in 2020.

The effect of prepregnancy body mass index on maternal micronutrient status: a meta-analysis

The relationship between prepregnancy body mass index (BMI) and maternal micronutrient status is inconsistent and has not received sufficient attention. This meta-analysis aimed to evaluate the effect of prepregnancy BMI on micronutrient levels in pregnant women. PubMed, Embase, Web of Science, and the Cochrane Library were searched for articles that contained information on micronutrient levels and prepregnancy BMI. A random-effects model was used to determine the association between prepregnancy BMI and maternal micronutrient status. Sixty-one eligible articles were eventually included, with 83,554 participants. Vitamin B12, folate, vitamin D, iron and ferritin were the main micronutrients evaluated in our meta-analysis. Prepregnancy obesity and overweight may lead to an increased risk of micronutrient deficiency, including vitamin B12, folate and vitamin D deficiency, while prepregnancy obesity or overweight may have no significant association with ferritin deficiency. Additionally, the results of the dose–response analyses demonstrated a possible significant inverse correlation between prepregnancy BMI and levels of micronutrient, except for iron and ferritin. Compared with women with normal weight, women who were overweight or obese prepregnancy have lower micronutrient concentrations and are more likely to exhibit micronutrient deficiency during pregnancy, which is harmful to both mothers and neonates.

Preterm birth increases placental expression of multidrug resistance (MDR) transporters irrespective of prepregnancy body mass index (BMI)

Context: Preterm birth (PTB) and suboptimal prepregnancy body mass index (BMI) operate through inflammatory pathways to impair fetoplacental development. Placental efflux transporters mediate fetal protection and nutrition, however few studies consider the effect of both PTB and BMI on fetal protection. We hypothesized that PTB would alter the expression of placental multidrug resistance (MDR) transporters and selected pro-inflammatory cytokines, and that maternal underweight and obesity would further impair placental phenotype. Objective: To determine whether placental MDR transporters P-glycoprotein (P-gp, encoded by ABCB1) and breast cancer resistance protein (BCRP/ABCG2), and pro-inflammatory cytokine levels are altered by PTB and maternal BMI. Design and Outcomes: A cross-sectional study was conducted to assess the effect of PTB (+/- chorioamnionitis), or the effect of maternal prepregnancy BMI on placental MDR transporter and interleukin [IL]-6 and 8 expression in 60 preterm and 36 term pregnancies. Results: ABCB1 expression was increased in preterm compared to term placentae (p=0.04). P-gp (p=0.008) and BCRP (p=0.01) immunolabeling was increased among all preterm compared to term placentae, with P-gp expression further increased in preterm pregnancies with chorioamnionitis (PTC, p=0.007). Placental IL-6 mRNA expression was decreased in PTC compared to term placentae (p=0.0005), and PTC was associated with the greatest proportion of anti-inflammatory medications administered during pregnancy. Maternal BMI group did not influence placental outcomes. Conclusions: PTB and infection, but not prepregnancy BMI, alter placental expression of MDR transporters and IL-6. This may have implications for fetal exposure to xenobiotics that may be present in the maternal circulation in pregnancies complicated by PTB.