Infant body composition relationship to maternal adipokines and fat mass: the PONCH study

Effects of prenatal exercise interventions on maternal body composition: A secondary analysis of the FitMum randomized controlled trial

The main objective of the study was to investigate the effects of prenatal exercise interventions on maternal body composition at 28 weeks gestation and 7-14 days after delivery. We also explored associations between physical activity (PA) per se and body composition. This study presents secondary outcomes of the FitMum randomized controlled trial, which included healthy inactive pregnant women at gestational age ≤ 15+0 weeks. They were randomized to structured supervised exercise training, motivational counselling on PA, or standard care. Maternal body composition was measured by doubly labeled water at 28 weeks gestation (n = 134) and by dual-energy X-ray absorptiometry scan 7-14 days after delivery (n = 117). PA, including moderate-to-vigorous-intensity PA (MVPA), active kilocalories, and steps, were measured continuously from inclusion to delivery by a wrist-worn activity tracker. One hundred fifty pregnant women were included with a median pre-pregnancy body mass index (BMI) of 24.1 (21.6-27.9) kg/m2. We found no differences between groups in fat mass, fat percentage or fat-free mass at 28 weeks gestation or 7-14 days after delivery. Visceral adipose tissue mass and bone mineral density measured 7-14 days after delivery did not differ between groups either. Linear regression analyses adjusted for pre-pregnancy BMI showed that a higher number of daily steps was associated with lower fat mass, fat percentage, and visceral adipose tissue mass at 28 weeks gestation and 7-14 days after delivery. Active kilocalories during pregnancy was positively associated with fat-free mass 7-14 days after delivery. Neither structured supervised exercise training nor motivational counselling on PA during pregnancy affected maternal body composition at 28 weeks gestation or 7-14 days after delivery compared to standard care. Interestingly, when adjusted for pre-pregnancy BMI, higher number of daily steps was associated with lower fat content during pregnancy and after delivery, whereas MVPA and active kilocalories were not. Trial registration: ClinicalTrials.gov; NCT03679130; 20/09/2018.

Adiponectin Deficiency Alters Placenta Function but Does Not Affect Fetal Growth in Mice

Adiponectin administration to pregnant mice decreases nutrient transport and fetal growth. An adiponectin deficiency, on the other hand, as seen in obese women during pregnancy, alters fetal growth; however, the mechanism is unclear. To determine the role of adiponectin on placenta function and fetal growth, we used adiponectin knockout, adiponectin heterozygote that displays reduced adiponectin levels, and wild-type mice on a control diet or high fat/high sucrose (HF/HS) diet. Triglycerides (TGs) in the serum, liver, and placenta were measured using colorimetric assays. Gene expression was measured using quantitative RT-PCR. Adiponectin levels did not affect fetal weight, but it reduced adiponectin levels, increased fetal serum and placenta TG content. Wildtype dams on a HF/HS diet protected the fetuses from fatty acid overload as judged by increased liver TGs in dams and normal serum and liver TG levels in fetuses, while low adiponectin was associated with increased fetal liver TGs. Low maternal adiponectin increased the expression of genes involved in fatty acid transport; Lpl and Cd36 in the placenta. Adiponectin deficiency does not affect fetal growth but induces placental dysfunction and increases fetal TG load, which is enhanced with obesity. This could lead to imprinting effects on the fetus and the development of metabolic dysfunction in the offspring.

Physical activity during pregnancy and association with changes in fat mass and adipokines in women of normal-weight or with obesity

Adipose tissue and adipokine concentrations change markedly during pregnancy, but the effects of physical activity on these changes are rarely studied. We aimed to assess physical activity levels in pregnant women of normal-weight (NW) or with obesity (OB), and to determine the relation with changes in fat mass and adipokines. In each trimester, pregnant women (136 NW, 51 OB) were interviewed about their physical activity and had their body composition, leptin, soluble leptin receptor (sOB-R) and adiponectin determined. NW reported higher activity and more aerobic exercise than OB during early pregnancy. Both groups maintained training frequency but reduced overall activity as pregnancy progressed. NW women reporting aerobic and/or resistance exercise and OB women reporting aerobic exercise had greater sOB-R increases (independent of BMI or gestational weight gain). In NW, exercise also associated with lower fat mass and leptin increases. Higher activity levels associated with lower gestational weight gain in both groups. The relationship between physical activity and adiponectin differed between NW and OB. Maternal exercise may partly mediate its beneficial effects through regulation of leptin bioavailability, by enhancing pregnancy-induced increases in sOB-R. This could be of particular importance in OB with pre-gestational hyperleptinemia and leptin resistance.

The Role of Leptin in Fetal Growth during Pre-Eclampsia

Leptin is secreted by the placenta and has a multi-facetted role in the regulation of functions related to pregnancy. Metabolic disorders and insufficient homeostatic compensatory mechanisms involving leptin during pregnancy play a decisive role in the development of pre-eclampsia (PE) and give rise to compromised intrauterine growth conditions and aberrant birth weight of offspring. This review was compiled to elucidate the metabolic background of PE and its relationship with adverse intrauterine growth conditions through the examination of leptin as well as to describe possible mechanisms linking leptin to fetal growth restriction. This review illustrates that leptin in PE is dysregulated in maternal, fetal, and placental compartments. There is no single set of unifying mechanisms within the spectrum of PE, and regulatory mechanisms involving leptin are specific to each situation. We conclude that dysregulated leptin is involved in fetal growth at many levels through complex interactions with parallel pregnancy systems and probably throughout the entirety of pregnancy.