Original Research
Obstetrics
Maternal and perinatal outcomes of pregnant women with SARS-CoV-2 infection at the time of birth in England: national cohort study

https://doi.org/10.1016/j.ajog.2021.05.016Get rights and content

Background

Some studies have suggested that women with SARS-CoV-2 infection during pregnancy are at increased risk of adverse pregnancy and neonatal outcomes, but these associations are still not clear.

Objective

This study aimed to determine the association between SARS-CoV-2 infection at the time of birth and maternal and perinatal outcomes.

Study Design

This is a population-based cohort study in England. The inclusion criteria were women with a recorded singleton birth between May 29, 2020, and January 31, 2021, in a national database of hospital admissions. Maternal and perinatal outcomes were compared between pregnant women with a laboratory-confirmed SARS-CoV-2 infection recorded in the birth episode and those without. Study outcomes were fetal death at or beyond 24 weeks’ gestation (stillbirth), preterm birth (<37 weeks’ gestation), small for gestational age infant (small for gestational age; birthweight at the <tenth centile), preeclampsia or eclampsia, induction of labor, mode of birth, specialist neonatal care, composite neonatal adverse outcome indicator, maternal and neonatal length of hospital stay after birth (3 days or more), and 28-day neonatal and 42-day maternal hospital readmission. Adjusted odds ratios and their 95% confidence interval for the association between SARS-CoV-2 infection status and outcomes were calculated using logistic regression, adjusting for maternal age, ethnicity, parity, preexisting diabetes mellitus, preexisting hypertension, and socioeconomic deprivation measured using the Index of Multiple Deprivation 2019. Models were fitted with robust standard errors to account for hospital-level clustering. The analysis of the neonatal outcomes was repeated for those born at term (≥37 weeks’ gestation) because preterm birth has been reported to be more common in pregnant women with SARS-CoV-2 infection.

Results

The analysis included 342,080 women, of whom 3527 had laboratory-confirmed SARS-CoV-2 infection. Laboratory-confirmed SARS-CoV-2 infection was more common in women who were younger, of non-White ethnicity, primiparous, or residing in the most deprived areas or had comorbidities. Fetal death (adjusted odds ratio, 2.21; 95% confidence interval, 1.58–3.11; P<.001) and preterm birth (adjusted odds ratio, 2.17; 95% confidence interval, 1.96–2.42; P<.001) occurred more frequently in women with SARS-CoV-2 infection than those without. The risk of preeclampsia or eclampsia (adjusted odds ratio, 1.55; 95% confidence interval, 1.29–1.85; P<.001), birth by emergency cesarean delivery (adjusted odds ratio, 1.63; 95% confidence interval, 1.51–1.76; P<.001), and prolonged admission after birth (adjusted odds ratio, 1.57; 95% confidence interval, 1.44–1.72; P<.001) were significantly higher for women with SARS-CoV-2 infection than those without. There were no significant differences (P>.05) in the rate of other maternal outcomes. The risk of neonatal adverse outcome (adjusted odds ratio, 1.45; 95% confidence interval, 1.27–1.66; P<.001), need for specialist neonatal care (adjusted odds ratio, 1.24; 95% confidence interval, 1.02–1.51; P=.03), and prolonged neonatal admission after birth (adjusted odds ratio, 1.61; 95% confidence interval, 1.49–1.75; P<.001) were all significantly higher for infants with mothers with laboratory-confirmed SARS-CoV-2 infection. When the analysis was restricted to pregnancies delivered at term (≥37 weeks), there were no significant differences in neonatal adverse outcome (P=.78), need for specialist neonatal care after birth (P=.22), or neonatal readmission within 4 weeks of birth (P=.05). Neonates born at term to mothers with laboratory-confirmed SARS-CoV-2 infection were more likely to have prolonged admission after birth (21.1% compared with 14.6%; adjusted odds ratio, 1.61; 95% confidence interval, 1.49–1.75; P<.001).

Conclusion

SARS-CoV-2 infection at the time of birth is associated with higher rates of fetal death, preterm birth, preeclampsia, and emergency cesarean delivery. There were no additional adverse neonatal outcomes, other than those related to preterm delivery. Pregnant women should be counseled regarding risks of SARS-CoV-2 infection and should be considered a priority for vaccination.

Key words

birth
COVID-19
fetal death
neonatal outcome
obstetrics
preeclampsia
pregnancy
preterm birth
stillbirth

Cited by (0)

The authors I.G.U. and J.E.J. are joint first authors.

The authors J.V.D.M. and A.K. are joint senior authors.

Healthcare Quality Improvement Partnership program grant (National Maternity and Perinatal Audit). The funder had no involvement in the design of the study, interpretation of the data, writing of the manuscript, or approval of the manuscript for publication. The National Maternity and Perinatal Audit is commissioned by the Healthcare Quality Improvement Partnership (HQIP; www.hqip.org.uk) as part of the National Clinical Audit and Patient Outcomes Programme and funded by NHS England and the Scottish and Welsh Governments.

All authors except J.V.D.M., T.D., and E.M. receive full or partial salary funding provided through the Healthcare Quality Improvement Partnership to the Royal College of Obstetricians and Gynaecologists (RCOG). E.M., T.D., J.E.J., and L.W. are members of the RCOG COVID-19 guidance cell which produces clinical guidance and policy documents to support the management of pregnant women during the pandemic in the United Kingdom.

Cite this article as: Gurol-Urganci I, Jardine JE, Carroll F, et al. Maternal and perinatal outcomes of pregnant women with SARS-CoV-2 infection at the time of birth in England: national cohort study. Am J Obstet Gynecol 2021;225:522.e1-11.

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