Weight gain affects pregnancy outcomes in women with GDM, obesity

In women with gestational diabetes (GDM) and obesity, gestational weight gain (GWG) appears to influence pregnancy outcomes, according to data presented at SMFM 2022.

Using data from the 2018 US natality database, a retrospective study was conducted on women with singleton, term births who had GDM (n=157,711). Of these, 71,849 were obese. Nearly half (48 percent) of the participants had recommended GWG, while the rest either had inadequate (19 percent) or excessive GWG (34 percent). Among the women with obesity, 46 percent fell under the class I category, 29 percent had class II obesity, and 24 percent had class III obesity. Pregnancy outcomes included gestational hypertension, Caesarean delivery, macrosomia, and need for neonatal-assisted ventilation (NAV) and neonatal intensive care unit (NICU) admission.

GDM

In the overall cohort, compared with women with recommended GWG, those with inadequate GWG had increased risk of developing gestational hypertension (adjusted odds ratio [aOR], 1.37, 95 percent confidence interval [CI], 1.31–1.44), having a Caesarean delivery (aOR, 1.20, 95 percent CI, 1.17–1.24), and need for NAV >6 hours (aOR, 1.29, 95 percent CI, 1.10–1.52). [SMFM 2022, abstract 403]

Similarly, women with excessive GWG also had increased risk of having gestational hypertension (aOR, 2.06, 95 percent CI, 1.98–2.13), Caesarean delivery (aOR, 1.90, 95 percent CI, 1.85–1.94), and need for NAV >6 hours (aOR, 1.62, 95 percent CI, 1.43–1.84) compared with women with recommended GWG. The risk of the other pregnancy outcomes of macrosomia (aOR, 2.40, 95 percent CI, 2.31–2.49) and need for NICU admission (aOR, 1.41, 95 percent CI, 1.35–1.47) was also higher in this subgroup.

GDM + obesity

When obesity was factored in however, all obese women with inadequate GWG had a lower risk of having a Caesarean delivery (aOR, 0.89, 95 percent CI, 0.85–0.93), macrosomia (aOR, 0.79, 95 percent CI, 0.74–0.84), and need for NICU admission (aOR, 0.89, 95 percent CI, 0.83–0.97) compared with women with recommended GWG. The risk of developing gestational hypertension was also lower, but only among women with class II and III obesity (aOR, 0.91, 95 percent CI, 0.86–0.97). [SMFM 2022, abstract 1113] 

Excessive GWG, on the other hand, was associated with increased risk for all evaluated pregnancy outcomes in women across all obesity classes (p<0.001).

Redefine guidelines?

Collectively, the findings demonstrate that excessive weight gain was associated with increased maternal and neonatal morbidity in pregnant women with GDM regardless of obesity status, noted presenting author Dr Viktoriya London from the Maimonides Medical Center, Brooklyn, New York, US.

Whereas for participants with inadequate weight gain, obesity appeared to generate a favourable effect, as reflected by the reduction in risk of maternal and neonatal morbidity when obesity was taken into consideration. 

The current Institute of Medicine guidelines for GWG are not stratified according to severity of obesity or comorbidities. The findings imply that redefining the recommended GWG may benefit obese women with GDM due to the potential for decreased rates of pregnancy outcomes, said London. “Thus, the current recommended GWG for all obese women may need to be modified based on BMI class.”