Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection During Pregnancy In China: A Retrospective Cohort Study
Authors: Yin Ming-Zhu , Zhang Li-juan , Deng Guang-Tong , Han Chao-Fei , Shen Min-Xue , Sun Hong-Yin , Zeng Fu-Rong , Zhang Wei , Chen Lan , Luo Qing-Qing , Yao Du-Juan , Wu Min , Yu Shi-Huan , Chen Hui , Baud David , Chen Xiang 
Published: April 2020

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been identified as the cause of the ongoing worldwide epidemic of Coronavirus Disease 2019 (COVID-19) in China and worldwide. However, there were few studies about the effects of SARS-CoV-2 infection on pregnant women.

Methods

In this retrospective cohort study, we enrolled 31 pregnant women and 35 non-pregnant women from Jan 28 to Feb 28, 2020 to evaluate the effects of SARS-CoV-2 infection during pregnancy. Inflammatory indices were used to assess the severity of COVID-19. Evidence of vertical transmission was determined by laboratory confirmation of SARS-CoV-2 in amniotic fluid, placenta, neonatal throat and anal swab and breastmilk samples.

Findings

Compared with non-pregnant women, pregnant women had a significantly lower proportion of fever (54·8% vs. 87·5%, p= 0.006), a shorter average interval from onset to hospitalization (7·80 ±7·0d vs. 13·2 ± 8·2d, p= 0.005), and a higher proportion of severe or critical COVID-19 (32·3% vs. 11·4%, p=0.039). Neutrophil-to-lymphocyte ratio (NLR) and systematic immune-inflammation-based prognostic index (SII) were significantly higher on admission in severe/critical pneumonia group than moderate pneumonia group. We could not detect the presence of SARS-CoV-2 by RT-PCR in amniotic fluid, placenta, neonatal throat and anal swab and breastmilk samples.

Interpretation

The clinical symptoms of COVID-19 in pregnant women were insidious and atypical, compared with those in non-pregnant patients. SII and NLR could be a useful marker to evaluate the severity of COVID-19. There was no evidence of vertical transmission during pregnancy with SARS-CoV-2 infection.

Funding

National Natural Science Foundation of China and Research Funds for the Central Universities.

Research in context

Evidence before this study

We searched PubMed, Embase and Web of science for articles published up to March 1st, 2020, using the keywords (“novel coronavirus” OR “2019 novel coronavirus” OR “2019-nCoV” OR COVID-19 OR SARS-CoV-2) AND (pregnancy OR “maternal infection” OR “fetal infection”) AND “Cohort studies”.

We identified no published cohort studies on pregnant women with the 2019 novel coronavirus disease (COVID-19) infection.

Added value of this study

For this retrospective cohort study, we reviewed clinical records, laboratory findings, and chest CT scans from 31 pregnant women and 35 non-pregnant women from Jan 28 to Feb 28, 2020 to evaluate the effects of SARS-CoV-2 infection during pregnancy. Inflammatory indices were used to assess the severity of COVID-19. Evidence of vertical transmission was determined by laboratory confirmation of SARS-CoV-2 in amniotic fluid, placenta, neonatal throat and anal swab and breastmilk samples. Compared with non-pregnant women, pregnant women had a significantly lower proportion of fever (54·8% vs. 87·5%, p= 0.006), a shorter average interval from onset to hospitalization (7·80 ±7·0d vs. 13·2 ± 8·2d, p= 0.005), and a higher proportion of severe or critical COVID-19 (32·3% vs. 11·4%, p=0.039). Neutrophil-to-lymphocyte ratio (NLR) and systematic immune-inflammation-based prognostic index (SII) were significantly higher on admission in severe/critical pneumonia group than moderate pneumonia group. Amniotic fluid, placenta, neonatal throat and anal swab and breastmilk samples were tested for SARS-CoV-2 by RT-PCR and all results were negative.

Implications of all the available evidence

The clinical symptoms of COVID-19 in pregnant women were insidious and atypical, compared with those in non-pregnant patients. SII and NLR could be a useful marker to evaluate the severity of COVID-19. There was no evidence of vertical transmission during pregnancy with SARS-CoV-2 infection.