SARS-CoV-2 infection in pregnancy in Denmark – characteristics and outcomes after confirmed infection in pregnancy: a nationwide, prospective, population-based cohort study

  1. Anna Aabakke
  2. Lone Krebs
  3. Tanja Petersen
  4. Frank Kjeldsen
  5. Giulia Corn
  6. Karen Wøjdemann
  7. Mette Ibsen
  8. Fjola Jonsdottir
  9. Elisabeth Rønneberg
  10. Charlotte Andersen
  11. Iben Sundtoft
  12. Tine Clausen
  13. Julie Milbak
  14. Lars Burmester
  15. Birgitte Lindved
  16. Annette Thorsen-Meyer
  17. Mohammed Khalil
  18. Birgitte Henriksen
  19. Lisbeth Jønsson
  20. Lise Lotte Andersen
  21. Kamilla Karlsen
  22. Monica Pedersen
  23. Aase Klemmensen
  24. Marianne Vestgaard
  25. Dorthe Thisted
  26. Manrinder Tatla
  27. Line Andersen
  28. Anne-Line Brülle
  29. Arense Gulbech
  30. Charlotte Andersson
  31. Richard Farlie
  32. Lea Hansen
  33. Lone Hvidman
  34. Anne Sørensen
  35. Sidsel Rathcke
  36. Katrine Rubin
  37. Lone Petersen
  38. Jan Stener Joergensen
  39. Lonny Stokholm
  40. Mette Bliddal

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Abstract

Objective To identify risk factors for and outcomes after SARS-CoV-2 infection and severe COVID-19 in pregnancy Design Prospective population-based cohort study Setting Denmark Population All pregnancies between 1 March and 31 October 2020 Methods Using data from the Danish National Patient Register and Danish Microbiology Database and prospectively registered data from medical records, we compared women with a positive SARS-CoV-2 test during pregnancy to non-infected pregnant women. Severe infection was defined as hospital admission due to COVID-19. Main Outcome Measures Pregnancy, delivery, maternal, and neonatal outcomes. Results Among 82,682 pregnancies, 418 women had SARS-CoV-2 infection during pregnancy, corresponding to an incidence of 5.1 per 1000 pregnancies, 23 (5.5%) of which required hospital admission due to COVID-19. Risk factors for infection were asthma (OR 2.19 [1.41–3.41]) and being foreign born (OR 2.12 [1.70–2.64]). Risk factors for hospital admission due to COVID-19 included obesity (OR 2.74 [1.00–7.51]), smoking (OR 4.69 [1.58–13.90]), infection after gestational age in weeks (GA) 22 (GA 22–27: OR 3.77 [1.16–12.29]; GA 28–36: OR 4.76 [1.60–14.12]) and having asthma (OR 4.53 [1.39–14.79]). We found no difference in any obstetric or neonatal outcomes. Conclusions Severe outcomes of SARS-CoV-2 infection in pregnancy are rare. Funding The Danish Ministry of Higher Education and Science (Reg. 0237-00007B) and The Region of Southern Denmark and Region Zealand’s shared fund for joint health research projects (Reg. A767) Keywords Severe acute respiratory syndrome coronavirus 2; COVID-19; Obstetric delivery; Pregnancy complications; Pregnancy outcome; Cohort studies; Prospective studies.

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  1. Version published to 10.22541/au.170666114.47690574/v1
  2. Version published to 10.1111/aogs.14252
  3. ScreenIT

    SciScore for 10.1101/2021.06.08.21258480: (What is this?)

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

    Table 1: Rigor

    Ethicsnot detected.
    Sex as a biological variableThe study used prospectively registered data from medical records registered in the Danish COVID-19 in pregnancy database (DCOD) and register data obtained from the following national registers: the Danish National Patient Register (DNPR),12 Danish Microbiology Database (MiBa),13 and the Civil Registration System.14 The overall study population was identified in DNPR and comprised all women registered with a pregnancy or birth-related ICD10 diagnosis or procedure between March 1 and October 31, 2020 as specified in Table S1.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Cell Line AuthenticationAuthentication: Non-reported cases identified by validation who were pregnant at the time of a positive SARS-CoV-2 PCR test were entered into the DCOD retrospectively.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Data were analysed using Stata/MP16 (64-bit) and IBM SPSS statistics 27 (SPSS Inc).
    SPSS
    suggested: (SPSS, RRID:SCR_002865)

    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:
    The study also has limitations. First, the register dataset was pseudoanonymised, making individual-level linkage to DCOD impossible. Additionally, data on SARS-CoV-2 cases in the DCOD were based on medical records and data in the national registers were based on mandatory nationally registered data, and these data might not be directly comparable. Nevertheless, the number of SARS-CoV-19 cases was similar in the two cohorts, and data did not differ significantly between the cohorts, indicating agreement between cases and data sources. Some descriptive variables including BMI and smoking status are not reported in the registers before delivery and are not reported for early pregnancy losses. The DCOD thus provided complete data, and made national surveillance of the infection possible to support national guidelines until register data were available.23–25 Secondly, the lack of association in some outcomes for severe cases might be due to low numbers. Thirdly, universal testing of pregnant women was not implemented in Denmark before May 2020, and we might therefore have missed SARS-CoV-2-positive cases early in the inclusion period. Furthermore, MiBa only included information on PCR tests, thus missing pregnant women diagnosed through antigen or antibody tests, which were possibly milder cases. Inclusion of these plausibly positive but non-identified cases in the comparison population of pregnancies might have affected our estimates.

    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.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  4. Version published to 10.1101/2021.06.08.21258480 on medRxiv