Association Between Gestational Weight Gain and Delayed Onset of Lactogenesis II: a Systematic Review and...

Gestational weight gain (GWG) may be associated with delayed onset of lactogenesis II (DOL II), but it is still unclear and controversial. The study aims to evaluate the relationship between GWG and DOL II. A comprehensive search was performed in 10 electronic databases from inception to May 21, 2023, for studies that reported outcomes in breastfeeding. Data were extracted by two independent reviewers. A meta-analysis was conducted to calculate the pooled estimates of association using random-effect models with Review Manager (RevMan) software version 5.4. The primary outcome was the rate of DOL II. In this study, 248,515 women were included in 16 eligible articles. Women with excessive GWG have a higher risk of DOL II (odds ratio [OR] = 1.28; 95% confidence interval [CI]: 1.15-1.43). Specifically, prepregnancy overweight and obese women with GWG above recommendations (OR = 3.01, 95% CI: 1.38-6.57) and underweight women with excessive GWG before pregnancy have a higher risk of DOL II (OR = 3.32, 95% CI: 1.69-6.53). Nonetheless, there is no distinction between women with inadequate GWG and those with adequate GWG in DOL II(OR = 1.08, 95% CI: 0.88-1.33). In addition, the women whose GWG is above the recommendations also tend to stop exclusive breastfeeding 1 month postpartum (OR = 0.82, 95% CI: 0.80-0.85). Excessive GWG has a negative influence on the timing of the onset of lactogenesis and exclusive breastfeeding within 1 month postpartum.