key: cord-0032014-xpo60hwa
authors: Gulersen, Moti; Lenchner, Erez; Grunebaum, Amos; Chervenak, Frank A.; Bornstein, Eran
title: Impact of COVID-19 pandemic on maternal and neonatal morbidities in the United States
date: 2022-05-20
journal: Am J Obstet Gynecol MFM
DOI: 10.1016/j.ajogmf.2022.100667
sha: e7ec2ddb27dde4fd75eb302d12f6b4865595ec03
doc_id: 32014
cord_uid: xpo60hwa

nan

pandemic group), while the comparison group included similar births from 1/1/15-2/29/20 (i.e. prepandemic group). March 2020, when the SARS-CoV-2 outbreak was declared a global pandemic, 3 was considered a washout period and excluded from our analysis. Cases with missing data were also excluded.

Baseline characteristics, the incidences of preterm birth (prior to 24, 28, 34, and 37 weeks), and several maternal and neonatal complications were compared between the two groups using Pearson's chi-squared test with statistical significance set at P < 0.05. Multivariable logistic regression was used to adjust for the following potential confounders: maternal age, body mass index, race or ethnic group, chronic hypertension, pregestational diabetes, history of preterm birth, and tobacco use. Data were presented as unadjusted and adjusted Odds Ratios (aOR) with 95% confidence intervals (95% CI). An institutional review board approval was not required as the reported de-identified data are publicly available through a data use agreement with the NCHS. 4 Results 18,071,658 live births were included, of which 2,641,746 (14.6%) were in the pandemic group, and 15,429,912 (85.4%) were in the pre-pandemic group. Higher rates of chronic hypertension, gestational hypertension/preeclampsia, pregestational diabetes, prior preterm birth, as well as lower rates of tobacco use were seen in the pandemic compared to the pre-pandemic group ( Table 1) . The rates of preterm birth were nearly identical between the two groups, conferring no clinical difference in this outcome during the COVID-19 pandemic ( 

Based on a large US population database, we report several characteristics and pregnancy complications that increased during the COVID-19 pandemic. Specifically, we detected higher rates of chronic hypertension, gestational hypertension/preeclampsia, pregestational diabetes, prior preterm birth, as well as lower rates of tobacco use. In addition, pregnancies in the pandemic group had slightly higher odds of maternal transfusion, uterine rupture, and immediate and prolonged neonatal assisted ventilation. Despite prior data suggesting that COVID-19 in pregnancy is associated with an increased risk for preterm birth, 1,5 we did not detect a difference in overall preterm birth rates in the US population during the pandemic. Given that preterm birth is more common in symptomatic patients with COVID-19, which represent a minority of pregnancies during the pandemic, 1,5 this did not translate to a clinically significant difference in preterm birth rates on a national level. It is unclear why the COVID-19 pandemic was associated with higher odds of immediate and prolonged neonatal assisted ventilation despite similar preterm birth rates and adjusting for potential confounders such as pregestational diabetes. It is possible that unmeasured confounders may have contributed to these findings.

An association between SARS-CoV-2 infection and hypertensive disorders of pregnancy has been suggested in previous smaller studies, 6 and our findings confirm this association in a large populationbased cohort. The decreased incidence in tobacco use may reflect an overall trend to stop smoking during the pandemic given concerns regarding SARS-CoV-2 being a respiratory pathogen.

Our study is limited by the retrospective nature of birth certificate databases and the information available for analysis. Furthermore, as often seen in large population-based studies, although the comparison of several baseline characteristics and outcomes reached statistical significance, the magnitude of some of these differences were very small, suggesting limited, if any, clinical significance. In summary, our findings exploring the impact COVID-19 pandemic had on the overall rate of pregnancy complications in the US are overall reassuring.

Disease severity and perinatal outcomes of pregnant patients with coronavirus disease 2019 (COVID-19)

Association of SARS-CoV-2 infection with serious maternal morbidity and mortality from obstetric complications

World Health Organization. WHO Coronavirus disease 2019 (COVID-19) Situation Report -51

World Health Organization

SARS-CoV-2 and the subsequent development of preeclampsia and preterm birth: evidence of a dose-response relationship supporting causality

Preeclampsia and COVID-19: results from the INTERCOVID prospective longitudinal study

Data are presented as mean ± SD or No. (%)

Table 2. Adverse maternal and neonatal outcomes compared between the two groups

Data are presented as number (%) and odds ratios with 95% confidence intervals

*Models were adjusted for maternal age, body mass index, race or ethnic group, chronic hypertension, pregestational diabetes, history of preterm birth, and tobacco use