Neonatal and maternal outcomes following SARS-CoV-2 infection and COVID-19 vaccination

Summary in plain English

Background

As part of our COVID-19 in Pregnancy in Scotland (COPS) study, we explored the link between infection with SARS-CoV-2 (which causes COVID-19 disease) during pregnancy and the health outcomes of mothers and newborns.

The health outcomes for newborns we examined were:

• Stillbirth: death of a baby before birth
• Neonatal death: death of a newborn baby in the first 28 days of life
• Extended perinatal mortality: total of stillbirth and neonatal deaths
• Low and very low Apgar score: a health rating tool for newborns which indicates whether a baby needs extra care
• Small and very small-for-gestational age: refers to the weight of the newborn at birth
• Preterm and very preterm birth: early birth of a baby at <37 weeks and <32 weeks of pregnancy.

The health outcomes for mothers we examined were:

• Admission to critical care (in an intensive care or high dependency unit) or death
• High blood pressure
• Pregnancy-related bleeding
• Blood clots that form in a vein and can travel to the lungs (DVT and pulmonary embolus)

We also explored the link between COVID-19 vaccination during pregnancy and these health outcomes, to confirm that vaccines are safe to give in pregnancy.

Why did we carry out this work?

Vaccination uptake has been relatively low among pregnant women. As such, there is a need to provide evidence to show that COVID-19 vaccination is a safe way for pregnant women to protect themselves and their babies against infection. We wanted to help pregnant women and healthcare providers make informed decisions by providing statistical evidence on the effects that SARS-CoV-2 infection and COVID-19 vaccination have on pregnancy.

What data did we use?

SARS-CoV-2 infection and outcomes for newborns and mothers

We used the COPS study database that contained health information from 81,441 women with singleton pregnancies that were ongoing on 18 May 2020 (when community SARS-CoV-2 testing became widely available), or started between 18 May 2020 and 2 June 2021, and that ended in a live or stillbirth.

Of these, 4,074 women had infection during pregnancy, and these were compared to 12,222 control women who did not have infection during pregnancy. Women who had infection during pregnancy were more likely than controls to be from deprived and urban areas.

COVID-19 vaccination and outcomes for newborns and mothers.

The COPS study database contained information on 55,167 women with singleton pregnancies that were ongoing on 8 December 2020 (the start of the COVID-19 vaccination programme), or started between 8 December 2020 and 2 June 2021, and that ended in a live or stillbirth.

Of these, 11,379 women were vaccinated during pregnancy, and these were compared to 22,758 control women who were not vaccinated during pregnancy. Women who were vaccinated during pregnancy were less likely than controls to be from deprived areas and were less likely to be smokers. Most vaccinated women received a vaccine created by Pfizer called the BioNTech BNT162b2 vaccine.

What did we find?

SARS-CoV-2 infection and outcomes for newborns and mothers

We found that SARS-CoV-2 infection during pregnancy increased the risk of mothers being admitted to critical care, mothers having blood clots, and preterm and very preterm birth. We found no evidence of a link between infection during pregnancy and increased risk of the other outcomes examined.

COVID-19 vaccination on newborn and mother outcomes

We found no evidence that COVID-19 vaccination during pregnancy was associated with increased risk of any of the harmful outcomes for either mothers or newborns that we examined.

Why is this important?

The study provides high-quality evidence on the risks of SARS-CoV-2 infection during pregnancy. Our findings can help to inform the care of women who have confirmed infection during pregnancy. For example, our results support current guidance that women who have infection during pregnancy should be offered additional assessment for blood clots.

We found no evidence that COVID-19 vaccination during pregnancy was associated with any negative health outcomes. This supports current recommendations that COVID-19 vaccination remains the safest and most effective way for pregnant women to protect themselves and their babies from the risks associated with SARS-CoV-2 infection.

Note

This summary was written by PPI Research & Operations assistant Laura Gonzalez Rienda. The summary was also checked by team members directly involved in the study.