What are the Effects of Gestational Weight Gain for Women with Obesity?

Managing gestational weight gain in women with can improve pregnancy outcomes.

Among women of reproductive age, it is estimated that 20 percent of them are women with obesity¹. Women with obesity experience increased risks of complications during pregnancy that include gestational diabetes, gestational weight gain, pre-term birth, and higher rates of a cesarean delivery.^1,2 While the clinical impacts of weight on fertility are known, the importance of weight gain during pregnancy cannot be understated, particularly for women who are at an increased risk of an adverse pregnancy outcome. Managing gestational weight gain in women with a pre-pregnancy BMI of ≥ 30 is key to optimizing pregnancy outcomes.

Predictors of Pregnancy Outcomes

A 2018² retrospective study investigated pre-pregnancy obesity, gestational diabetes, and gestational weight gain on pregnancy outcomes. Complete data was collected for 1,004 women of reproductive age (Mage = 34.5). The mean pre-pregnancy BMI was 23.9 kg/m² and the mean age at delivery was 39.7 +/- 1.7 weeks. The authors found that gestational weight gain was the strongest predictor of an adverse maternal and fetal outcome compared to well-treated gestational diabetes or pre-pregnancy BMI. Neonates born to women with gestational diabetes were at an increased risk of hyperbilirubinemia compared to mothers with normal glucose tolerance. No increased risk of a Cesarean delivery was found in mothers with gestational diabetes. Higher pre-pregnancy BMI in older women was associated with gestational diabetes but not found to be a risk factor for an adverse pregnancy outcome, which was a different finding from other studies.³ Macrosomia among women with gestational diabetes occurred more frequently than in the normal glucose tolerant women.

Gestational Weight Gain Guidelines and Risks

The current guidelines for weight gain during pregnancy for women with obesity and pre-pregnancy BMI of > 30KG is 11 – 20 pounds.⁴ Neonatal risks of excessive gestational weight gain include macrosomia and infants who are large for their gestational age. Additional risks summarized in a 2017 study⁴ include lower five-minute APGAR score, seizures, hypoglycemia, polycythemia, and meconium aspiration syndrome. The research goes on to report elevated and greater concerns for long-term outcomes such as childhood obesity. Managing gestational weight is not without challenges because women do need to gain weight during pregnancy to meet maternal and fetal needs. As reported in the 2017 study, improved maternal outcomes were observed in Cesarean deliveries, preeclampsia, and operative vaginal deliveries in women with obesity that either gained less weight than the guidelines or lost weight during pregnancy. However, there are risks with weight loss during pregnancy that include low-weight births and neonates who are small for their gestational age. The authors caution that until more is known about low gestational weight or gestational weight loss, clinicians should advise their patients with obesity to abide the 11-20 pound weight-gain guideline.

Helping Women With Manage Gestational Weight

The American Congress of Obstetricians and Gynecologists (ACOG) suggests a patient-centered approach to helping patients with obesity manage their weight during pregnancy. Health care providers should consider motivational interviewing to engage their patients about behavior change.⁵ Doctors and health care providers should also work with their patients to dispel myths about pregnancy, for example, the “eating for 2” myth and talk with patients about healthy caloric intake ranges and energy expenditure in the form of physical activities that are safe during pregnancy. Working collaboratively with patients to develop a supervised Low Calorie Diet (LCD) plan to foster healthy and safe weight gain during pregnancy, particularly for patients with pre-pregnancy BMI of ≥ 30 is an important step and can be key in ensuring an optimal pregnancy outcome.

Sources:

1. Obesity and female infertility: Potential mediators of obesity’s impact
2.  Pre-pregnancy obesity, gestational diabetes or gestational weight gain: Which is the strongest predictor of pregnancy outcomes?
3. The influence of maternal BMI and gestational diabetes on pregnancy outcome
4. Gestational weight gain
5. The American Congress of Obstetricians and Gynecologists (ACOG)

About the Author: Dr. Dawn M. Sweet has over 20 years of experience in the field of communication. Dr. Sweet has given several invited talks to and workshops for academic and private sector audiences on the role of nonverbal and verbal communication in achieving positive outcomes and mitigating bias. Her research has been published in several top ranked peer-review journals, and it has been featured on NPR’s River to River / All Things Considered, Buzzfeed, and Science Daily. Her research has also been used to inform expert testimony.