Role of Perinatal Biological Factors in Delayed Lactogenesis II Among Women With Pre-pregnancy Overweight and Obesity

Abstract

Background: Pre-pregnancy overweight and obesity are negatively associated with delayed onset of lactogenesis II (OL), but the mechanisms by which these conditions affect OL are still unclear. Objectives: To identify biological factors related to pre-pregnancy overweight/obesity and determine whether these biological factors were associated with delayed OL in this population. Methods: In this prospective observational study, we assigned 72 primipara to a pre-pregnancy overweight/obese group (n = 36) and a normal-weight group (n = 36). Blood samples were collected at 37 w of gestation and 48 h postpartum and assayed for levels of the following hormones: leptin, insulin, estradiol, prolactin (PRL), progesterone, and oxytocin. The primary outcome was timing of OL, estimated by maternal perception of breast fullness. We used linear-regression analysis to determine associations between hormones and delayed OL. Results: Sixty-three participants (87.5%) had complete data. OL occurred later in overweight/obese than in normal-weight women (p