COVID-19 Evidence Alerts
from McMaster PLUSTM

Current best evidence for clinical care (more info)

Prognosis Huntley BJF, Huntley ES, Di Mascio D, et al. Rates of Maternal and Perinatal Mortality and Vertical Transmission in Pregnancies Complicated by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-Co-V-2) Infection: A Systematic Review. Obstet Gynecol. 2020 Aug;136(2):303-312. doi: 10.1097/AOG.0000000000004010.

OBJECTIVE: To ascertain the frequency of maternal and neonatal complications, as well as maternal disease severity, in pregnancies affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

DATA SOURCES: MEDLINE, Ovid,, MedRxiv, and Scopus were searched from their inception until April 29, 2020. The analysis was limited to reports with at least 10 pregnant patients with SARS-CoV-2 infection that reported on maternal and neonatal outcomes.

METHODS OF STUDY SELECTION: Inclusion criteria were pregnant women with a confirmed diagnosis of SARS-CoV-2 infection. A systematic search of the selected databases was performed by implementing a strategy that included the MeSH terms, key words, and word variants for "coronavirus," "SARS-CoV-2," "COVID-19," and "pregnancy.r The primary outcomes were maternal admission to the intensive care unit (ICU), critical disease, and death. Secondary outcomes included rate of preterm birth, cesarean delivery, vertical transmission, and neonatal death. Categorical variables were expressed as percentages with number of cases and 95% CIs.

TABULATION, INTEGRATION, AND RESULTS: Of the 99 articles identified, 13 included 538 pregnancies complicated by SARS-CoV-2 infection, with reported outcomes on 435 (80.9%) deliveries. Maternal ICU admission occurred in 3.0% of cases (8/263, 95% CI 1.6-5.9) and maternal critical disease in 1.4% (3/209, 95% CI 0.5-4.1). No maternal deaths were reported (0/348, 95% CI 0.0-1.1). The preterm birth rate was 20.1% (57/284, 95% CI 15.8-25.1), the cesarean delivery rate was 84.7% (332/392, 95% CI 80.8-87.9), the vertical transmission rate was 0.0% (0/310, 95% CI 0.0-1.2), and the neonatal death rate was 0.3% (1/313, 95% CI 0.1-1.8).

CONCLUSION: With data from early in the pandemic, it is reassuring that there are low rates of maternal and neonatal mortality and vertical transmission with SARS-CoV-2. The preterm birth rate of 20% and the cesarean delivery rate exceeding 80% seems related to geographic practice patterns.


Discipline / Specialty Area Score
Pediatrics (General)
Pediatric Neonatology
Pediatric Hospital Medicine
Family Medicine (FM)/General Practice (GP)
Intensivist/Critical Care
Public Health
Infectious Disease
Comments from MORE raters

Family Medicine (FM)/General Practice (GP) rater

Of the 538 pregnant patients 462 (85.9%) had lab confirmed Covid-19 and only 435 had delivered by the time the authors presented this data. The data are heavily skewed to one country (China) with far fewer cases from Italy and the US. Thus the true rate of vertical transmission for this collection of cases is not known.

Intensivist/Critical Care rater

While further studied is needed, this review provides some reassurance that positive outcomes for mothers and babies are most common in COVID-19 infections occurring in pregnant women. While premature birth rates (20%) and c-section rates (80%?) are attributed to "regional practice patterns", further study and analysis is required. The matter of COVID-19 infections in pregnant women will require further aggregation of data and analysis.

Obstetrics rater

This systematic review showed a low rate of maternal critical illness and vertical transmission of SARS-CoV-2. The main concerns are preterm and Caesarean deliveries which should be manageable by most tertiary centers. The results are largely reassuring to women and obstetricians.

Public Health rater

This is an area that is changing rapidly and a living systematic review would be more useful.

Respirology/Pulmonology rater

Meta-analysis of international date regarding pregnancy outcomes in cases of Covid-19. As the authors discuss, there are significant limitations to this type of study, but the data seem reassuring about a lack of increased maternal and fetal mortality, and no evidence of vertical transmission.