Gestational Weight Gain as a Modifiable Risk Factor in Women with Extreme Pregestational BMI

Abstract

The global rise in obesity presents serious concerns, particularly due to its association with pregnancy complications such as gestational diabetes, preeclampsia, cesarean delivery, and fetal macrosomia. Maternal obesity also contributes to intergenerational health risks, increasing the likelihood of long-term issues in offspring. Preconception counseling is an essential preventive measure to reduce complications; however, many women miss this opportunity due to unplanned pregnancies. This study explores the impact of pregestational body mass index (BMI) and gestational weight gain (GWG) on pregnancy outcomes, underscoring the importance of routine monitoring of these parameters. Existing studies identify both BMI and GWG as independent risk factors for adverse maternal and neonatal outcomes, with elevated BMI combined with excessive GWG posing an even greater risk. Specifically, a BMI > 30 kg/m² doubles the risk of complications such as gestational diabetes, hypertension, and cesarean delivery. Additionally, a review of national and international guidelines highlights a lack of consensus on managing gestational weight gain in women with obesity, particularly regarding antepartum surveillance and timing of delivery. Similarly, no specific guidelines have been established for underweight pregnant women. Additionally, few studies have thoroughly assessed the maternal and fetal risks associated with underweight during pregnancy. Despite this, numerous studies have highlighted an increased risk of preterm birth (PTB) and small-for-gestational-age (SGA) infants. This narrative review emphasizes the need for further research to develop tailored guidelines for managing pregnant women based on pregestational BMI, ultimately improving maternal and neonatal health outcomes.

Keywords: BMI; GWG; inflammation; obesity; pregnant; underweight women.

Figure 1

Comparison of the increase in energy intake recommendations during pregnancy according to ACOG (2023) [29], Italian guidelines (2021) [30], and Most et al. (2019) [31].