COVID‐19 in pregnancy—characteristics and outcomes of pregnant women admitted to hospital because of SARS‐CoV‐2 infection in the Nordic countries

  1. Hilde Engjom
  2. Anna J.M. Aabakke
  3. Kari Klungsøyr
  4. Teresia Svanvik
  5. Outi Äyräs
  6. Eva Jonasdottir
  7. Lars Thurn
  8. Elin Jones
  9. Karin Pettersson
  10. Lill T. Nyfløt
  11. Iqbal Al‐Zirqi
  12. Siri Vangen
  13. Pétur B. Júlíusson
  14. Karin Källén
  15. Mika Gissler
  16. Lone Krebs

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Abstract

Introduction

Population‐based studies about the consequences of SARS‐CoV‐2 infection (COVID‐19) in pregnancy are few and have limited generalizability to the Nordic population and healthcare systems.

Material and methods

This study examines pregnant women with COVID‐19 in the five Nordic countries. Pregnant women were included if they were admitted to hospital between 1 March and 30 June 2020 and had a positive SARS‐CoV‐2 PCR test ≤14 days prior to admission. Cause of admission was classified as obstetric or COVID‐19‐related.

Results

In the study areas, 214 pregnant women with a positive test were admitted to hospital, of which 56 women required hospital care due to COVID‐19. The risk of admission due to COVID‐19 was 0.4/1000 deliveries in Denmark, Finland and Norway, and 3.8/1000 deliveries in the Swedish regions. Women hospitalized because of COVID‐19 were more frequently obese ( p  < 0.001) and had a migrant background ( p  < 0.001) compared with the total population of women who delivered in 2018. Twelve women (21.4%) needed intensive care. Among the 56 women admitted due to COVID‐19, 48 women delivered 51 infants. Preterm delivery ( n  = 12, 25%, p  < 0.001) and cesarean delivery ( n  = 21, 43.8%, p  < 0.001) were more frequent in women with COVID‐19 compared with women who delivered in 2018. No maternal deaths, stillbirths or neonatal deaths were reported.

Conclusions

The risk of admission due to COVID‐19 disease in pregnancy was low in the Nordic countries. A fifth of the women required intensive care and we observed higher rates of preterm and cesarean deliveries. National public health policies appear to have had an impact on the risk of admission due to severe COVID‐19 disease in pregnancy. Nordic collaboration is important in collecting robust data and assessing rare outcomes.

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  1. Version published to 10.1111/aogs.14160
  2. ScreenIT

    SciScore for 10.1101/2021.02.05.21250672: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board StatementIRB: The study and data collection were approved by Landspitali University Hospital, the National Bioethics Committee (reg.no.VSNb2020050016/03.0I) and the Icelandic Data Protection Authority (reg.no.20-106).
    Consent: The ethical approvals in DK, IS, NO and KUH exempted the studies from the principle of individual consent.
    Randomizationnot detected.
    Blindingnot detected.
    Power AnalysisThe study sample size was governed by the disease incidence, so no formal power calculation was performed.
    Sex as a biological variableThe study includes pregnant women with COVID-19 infection and hospital admission for at least 24 hours.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Data were retrieved from Hospital Discharge Registers and medical records at each participating obstetric unit and entered into a joint electronic database in REDCap (16, 17) hosted at Lund University.
    REDCap
    suggested: (REDCap, RRID:SCR_003445)
    Data analyses were performed using IBM SPSS statistics 21
    SPSS
    suggested: (SPSS, RRID:SCR_002865)
    1 (SPSS Inc., Chicago, IL, USA) and STATA 16SE.
    STATA
    suggested: (Stata, RRID:SCR_012763)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Further, our Nordic study was restricted to women with present infection with a limitation of 14 days between test and admission. Nevertheless, even if all admissions were included in the Nordic countries, the admission risk in DK, FI, SI and NO was lower than in Italy and the UK (0.8/1000 deliveries). Additionally, the rate of admission was considerably higher in the SE regions, which may reflect both higher population infection rates, but also selection bias with higher admission rates at university hospitals. The risk of hospital and intensive care admissions in the total population was also higher in SE compared to the other Nordic countries as illustrated in Figure S3. This may indicate that policies reducing the transmission in the general population also reduces the rate of hospital admission due to COVID-19 among pregnant women. Among pregnant women admitted with COVID-19 in the Nordic countries, obesity and migrant background were more common than in the 2018 birth population, corresponding to the findings of previous studies (13, 14, 23). This information is relevant when developing national public health strategies. In the Nordic countries, no maternal, fetal or neonatal deaths were registered among the pregnant women admitted with severe COVID-19 symptoms during the first four months of the pandemic. However, 21% of the women needed intensive care, which is higher than the proportion in previous population-based studies from UK, Italy and the Netherlands (13, 14, ...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

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  3. Version published to 10.1101/2021.02.05.21250672v1 on medRxiv