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. 2023 Mar;102(3):282-293.
doi: 10.1111/aogs.14512. Epub 2023 Jan 25.

Risk factors for and pregnancy outcomes after SARS-CoV-2 in pregnancy according to disease severity: A nationwide cohort study with validation of the SARS-CoV-2 diagnosis

Anna J M Aabakke  1   2   3 , Tanja G Petersen  4 , Karen Wøjdemann  5 , Mette H Ibsen  6 , Fjola Jonsdottir  7 , Elisabeth Rønneberg  7 , Charlotte S Andersen  8 , Anne Hammer  8 , Tine D Clausen  2   3 , Julie Milbak  2 , Lars Burmester  9 , Rikke Zethner  1   7 , Birgitte Lindved  10 , Annette Thorsen-Meyer  11 , Mohammed R Khalil  12 , Birgitte Henriksen  12 , Lisbeth Jønsson  13 , Lise L T Andersen  14 , Kamilla K Karlsen  14 , Monica L Pedersen  15 , Gitte Hedermann  16 , Marianne Vestgaard  16 , Dorthe Thisted  1   17 , Agnethe N Fallesen  18 , Josephine N Johansson  18 , Ditte C Møller  19 , Greta Dubietyte  19 , Charlotte B Andersson  20   21 , Richard Farlie  22 , Ane-Kersti Skaarup Knudsen  22 , Lea Hansen  23 , Lone Hvidman  23 , Anne N Sørensen  24 , Sidsel L Rathcke  24 , Katrine H Rubin  4   25 , Lone K Petersen  14   25 , Jan S Jørgensen  14 , Lone Krebs  3   11 , Mette Bliddal  4   25
Affiliations

Risk factors for and pregnancy outcomes after SARS-CoV-2 in pregnancy according to disease severity: A nationwide cohort study with validation of the SARS-CoV-2 diagnosis

Anna J M Aabakke et al. Acta Obstet Gynecol Scand. 2023 Mar.

Abstract

Introduction: We identified risk factors and outcomes associated with SARS-CoV-2 infection in pregnancy in a universally tested population according to disease severity and validated information on SARS-CoV-2 during pregnancy in national health registers in Denmark.

Material and methods: Cohort study using data from national registers and medical records including all pregnancies between March 1, 2020 and February 28, 2021. We compared women with a validated positive SARS-CoV-2 test during pregnancy with non-infected pregnant women. Risk factors and pregnancy outcomes were assessed by Poisson and Cox regression models and stratified according to disease severity defined by hospital admission status and admission reason (COVID-19 symptoms or other). Using medical record data on actual period of pregnancy, we calculated predictive values of the SARS-CoV-2 diagnosis in pregnancy in the registers.

Results: SARS-CoV-2 infection was detected in 1819 (1.6%) of 111 185 pregnancies. Asthma was associated with infection (relative risk [RR] 1.63, 95% confidence interval [CI] 1.28-2.07). Risk factors for severe COVID-19 disease requiring hospital admission were high body mass index (median ratio 1.06, 95% CI 1.04-1.09), asthma (RR 7.47, 95% CI 3.51-15.90) and gestational age at the time of infection (gestational age 28-36 vs < 22: RR 3.53, 95% CI 1.75-7.10). SARS-CoV-2-infected women more frequently had hypertensive disorders in pregnancy (adjusted hazard ratio [aHR] 1.31, 95% CI 1.04-1.64), early pregnancy loss (aHR 1.37, 95% CI 1.00-1.88), preterm delivery before gestational age 28 (aHR 2.31, 95% CI 1.01-5.26), iatrogenically preterm delivery before gestational age 37 (aHR 1.49, 95% CI 1.01-2.19) and small-for-gestational age children (aHR 1.28, 95% CI 1.05-1.54). The associations were stronger among women admitted to hospital for any reason. The validity of the SARS-CoV-2 diagnosis in relation to pregnancy in the registers compared with medical records showed a negative predictive value of 99.9 (95% CI 99.9-100.0) and a positive predictive value of 82.1 (95% CI 80.4-83.7).

Conclusions: Women infected with SARS-CoV-2 during pregnancy were at increased risk of hypertensive disorders in pregnancy, early pregnancy loss, preterm delivery and having children small for gestational age. The validity of Danish national registers was acceptable for identification of SARS-CoV-2 infection during pregnancy.

Keywords: COVID-19; cohort studies; obstetric delivery; pregnancy complications; pregnancy outcome; prospective studies; severe acute respiratory syndrome coronavirus 2; validation study.

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Conflict of interest statement

The authors have stated explicitly that there are no conflicts of interest in connection with this article.

Figures

FIGURE 1
FIGURE 1
Flow through the study.
See this image and copyright information in PMC

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