Gestational weight gain increases during COVID-19 pandemic

Compared with trends before the COVID-19 pandemic, gestational weight gain increased during the pandemic, as did the risk for excessive gestational weight gain, according to a research letter published in JAMA Network Open.

“These findings shed light on the associations of the pandemic with adverse pregnancy outcomes and highlight the need to address pandemic-related [gestational weight gain (GWG)], particularly among vulnerable populations, to minimize the public health impact,” Wangnan Cao, PhD, an assistant professor in the department of social medicine and health education at Peking University in Beijing, and colleagues wrote.

Cao and colleagues used data from the CDC National Center for Health Statistics to identify singleton births between Jan. 1, 2018, and Dec. 31, 2020. To evaluate GWG in the pandemic period — which was defined as March 1 through Dec. 31, 2020 — the researchers tracked continuous trends in GWG across the study period.

They also analyzed differences in trends in excessive GWG, which they defined as gaining more weight than advised by the Institute of Medicine's BMI-specific recommendations, between patients who delivered during the pandemic and those who delivered during a comparable period in 2019, and between patients who delivered in 2019 and in 2018.

In total, Cao and colleagues analyzed 2,847,592 births in 2020, 2,475,822 births in 2019 and 2,847,592 births in 2018. Between 2018 and 2020, there was a net increase of 0.06 kg in GWG (95% CI, 0.04-0.07). The greatest net increases in GWG between 2018 and 2020 were observed in:

• patients aged younger than 25 years (net change, 0.22 kg; 95% CI, 0.19-0.26);
• non-Hispanic Black patients (net change, 0.12 kg; 95% CI, 0.07-0.16);
• unmarried patients (net change, 0.16 kg; 95% CI, 0.13-0.19);
• patients with prepregnancy obesity (net change, 0.17 kg; 95% CI, 0.14-0.21); and
• Medicaid-insured patients (net change, 0.17 kg; 95% CI, 0.15-0.2).

Further comparison within the study population revealed that patients who delivered during the pandemic period had the greatest risk for excessive GWG (ratio of OR = 1.01; 95% CI, 1.01-1.02). Patient groups with the greatest risk for excessive GWG were similar to those who had the greatest net increase in GWG.

“Study limitations include self-reported height and weight before pregnancy and lack of information on COVID-19 infection on birth certificates,” Cao and colleagues cautioned. “Future studies that identify the period of maximum association of the COVID-19 pandemic with GWG may be useful.”