Pregnancy and COVID19

Overall, most pregnant women with COVID-19 disease appear to have mild to moderate disease and there have been no documented cases of vertical transmission. No study has determined to date whether pregnant women have a different risk of infection, as compared to non-pregnant women, after being exposed to the virus. Publications and reports on pregnancy-related outcomes to date have come from China and are summarized below. In addition, a recent statement from the Society of Obstetricians and Gynecologists of Canada (SOGC) on COVID and pregnancy has been issued and this is also briefly summarized.

  • The Report of the WHO-China Joint Mission on Coronavirus Disease 2019 found that pregnant women “do not appear to be at higher risk of severe disease”. They cite that in “an investigation of 147 pregnant women (64 confirmed, 82 suspected and 1 asymptomatic), 8% had severe disease and 1% were critical.” This is in contrast to 13.8% of total cases having severe disease and 6.1% (of total cases) with critical disease, according to the same report.
    • No data were provided by trimester of pregnancy.
    • Severe cases were defined as increased respiratory rate (≧30 breaths/ min) or oxygen saturation ≤93% at rest, or PaO2/FIO2 <300 mmHg.
    • Critical cases were defined as respiratory failure requiring mechanical ventilation, shock or other organ failure that requires intensive care.
  • Schwartz (2020) reviewed a total of 38 pregnant women with COVID-19 from multiple reports, all in the third trimester of pregnancy
    • There was no evidence of vertical transmission of the virus responsible for COVID-19
    • Overall, the symptom profile did not appear to differ between pregnant and non-pregnant cases with COVID-19 (Wang et al, Zhang et al).
    • In a retrospective single hospital comparison of 16 infected and 45 non-infected pregnant women reviewed (Zhang et al 2020 – not reviewed by PHO, as the article is in Chinese), there were no significant differences between the groups with respect to pregnancy complications such as severe preeclampsia, gestational diabetes, premature rupture of membranes, fetal distress, meconium-stained amniotic fluid, and premature delivery (among others).
    • In one case series reviewed by Schwartz of 9 pregnancies (Zhu et al, 2020), there were no cases of severe pneumonia among mothers, however intrauterine fetal distress (n=6), prematurity (n=6, 2 were twins) as well as 2 instances of disseminated intravascular coagulation in the infants were reported, one of which died. However, none of the infants tested positive for SARS-CoV-2 and the authors note that it is unclear whether intrauterine fetal distress was directly related to maternal COVID-19.
    • Schwartz noted that in contrast to SARS and MERS, COVID-19 has not resulted in maternal deaths.
  • Liu et al (2020) reported on 13 pregnant patients from areas outside China, 11 of which were in their 2nd trimester.
    • Preterm labour was the most common adverse outcome (6 cases).
    • One case of severe respiratory distress and multi-organ dysfunction and associated stillbirth was reported.
  • The studies reviewed did not assess whether risk of disease was different for pregnant versus non-pregnant women from the same exposure.
  • The SOGC’s March 13 opinion on COVID-19 in pregnancy states, based on knowledge of other respiratory illnesses in pregnancy, adverse pregnancy outcomes are most likely related to the severity of maternal respiratory compromise. They further state that data are too limited to determine estimates of adverse pregnancy outcomes.
    • They reviewed data from about 60 cases (some of the same articles as summarized in Schwartz (2020) and Liu, above) and the WHO-China joint mission report and concluded that the vast majority of these women have had mild to moderate pneumonia, with preterm labour being the most commonly reported adverse pregnancy outcome.
    • They also report lack of evidence for vertical transmission at present.

References

WHO. Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19). 2020. Available at: https://www.who.int/docs/default-source/coronaviruse/who-china-joint-mission-on-covid-19-final-report.pdf

Schwartz DA. 2020. An Analysis of 38 Pregnant Women with 2 COVID-19, Their Newborn Infants, and Maternal-Fetal Transmission of SARS-CoV-2: Maternal Coronavirus Infections and Pregnancy Outcomes. Archives of Pathology & Laboratory Medicine

Wang X, Zhou Z, Zhang J, Zhu F, Tang Y, Shen X. A Case of 2019 novel coronavirus in a pregnant woman with preterm delivery [Published online ahead of print February 28, 2020]. Clin Infect Dis. 2020. doi: 10.1093/cid/ciaa200.

Zhu H, Wang L, Fang C, et al. Clinical analysis of 10 neonates born to mothers with 2019-nCoV pneumonia. Transl Pediatr. 2020;9(1):51-60. doi: 10.21037/tp.2020.02.06. Available from: http://tp.amegroups.com/article/view/35919/28274

Liu Y, Chen H, Tang K, Guo Y. Clinical manifestations and outcomes of SARS-CoV-2 infection during pregnancy. J Infect 2020; https://doi.org/10.1016/j.jing.2020.02.028.

SOGC. Updated SOGC Committee Opinion – COVID-19 in Pregnancy. 2020. Available at: https://sogc.org/en/content/featured-news/Updated-SOGC-Committee-Opinion%E2%80%93%20COVID-19-in-Pregnancy.aspx