Covid-19 and stillbirth: What does the latest research say about possible complications?

New warnings from HSE and obstetricians will add to concerns of expectant mothers

For anyone having a baby, there is always concern about outcomes, and in the vast majority of cases pregnancy culminates in the delivery of a healthy baby. The arrival of Covid-19 has, however, heightened that worry.

Coronavirus infectivity and its effects are an additional risk to take on board. That applies, if you are pregnant, recently had a baby or are breastfeeding – notably, implications of Covid-19 for mother and baby.

The issuing of alerts this week after coroners in Ireland identified Covid-19 as a factor in four stillbirths during January and February has heightened concerns.

The deaths were potentially associated with Covid Placentitis, a condition which causes inflammation of the placenta. The cases prompted alerts from the Health Service Executive and the Institute of Obstetricians.

The further into pregnancy that a woman contracts Covid-19, the higher a chance of getting very sick, which makes their care more challenging.

While international experience shows it is “not unusual” for Covid-19 to cause placental infection, stillbirth was an “unusual complication”, Prof Peter McKenna, head of the HSE National Women and Infants Programme, said.

Further investigation is required to determine whether these cases are a result of causation or association.

What are the risks for mothers-to-be arising from Covid-19?

We still don’t fully know how this novel virus affects pregnant women and their babies. The latest research suggests pregnant women are no more likely to become infected with Covid-19 than women of a similar age who are not pregnant.

Most pregnant women who get the disease have mild to moderate symptoms and the risk of passing Covid-19 onto their baby is low. But pregnant women with symptoms may be more likely to be admitted to hospital and to need treatment in intensive care (ICU).

“There may be an increased rate of premature labour and stillbirth if you are pregnant and have Covid-19, whether or not you have symptoms,” the HSE says on it website.

A US Centres for Disease Control (CDC) study analysed the data of 23,434 pregnant women who had Covid-19. After adjusting for age, race, ethnicity and underlying conditions such as diabetes, cardiovascular disease, and chronic lung disease, pregnant women were three times more likely to be admitted to ICU, and 2.9 times more likely to receive mechanical ventilation compared to non-pregnant women in the same age group.

While absolute risk of death among pregnant women with Covid-19 remains low at 1.5 per 1,000, the risk is 70 per cent higher in pregnant women compared to non-pregnant women.

Physiological changes that women go through during pregnancy may account for this increased risk of severe Covid-19 symptoms. These changes include increased heart rate and oxygen consumption, decreased lung capacity, and decreased function of the immune system, it noted.

Older pregnant women were four times more likely to require mechanical ventilation and two times more likely to die compared to non-pregnant women of the same age group.

A smaller CDC study looked at impact on birth and infant outcomes. Of almost 4,000 infants born to women with Covid-19, some 12.9 per cent of them were born pre-term. In the general population, 10.2 per cent of babies are pre-term.

Among 610 infants tested for Covid-19, 2.6 per cent were found to be positive, though it is unclear how transmission occurred.

Maternal infections early in pregnancy often have a larger impact on an infant developmentally than infections occurring later on.

A UK study found pregnant women with the disease were more likely to experience a pre-term birth and their newborns were more likely to be admitted to a neonatal unit. Stillbirth and newborn death rates, however, were low.

Does the stillbirth findings underline the importance of vaccinating pregnant women?

The overwhelming advice is that all pregnant women should get the Covid-19 vaccine. The master of the Rotunda maternity hospital, Prof Fergal Malone, has repeated his call for pregnant women to be moved up the vaccination priority list following the stillbirths alert.

Widespread failure to appropriately include pregnant women in vaccine research means evidence about safety and efficacy in pregnancy has been limited and late in coming – though there is nothing to suggest any cause for concern.

What is the best advice in light of the alerts?

The usual preventative measures such as social distancing are especially important when pregnant.

Prof McKenna has advised that pregnant women who notice decreased foetal movements should immediately contact their hospital. This is particularly important if they have had Covid-19 in the past two to three weeks.

Pregnant women should continue to avoid acquiring the virus by adhering to public health measures and, if they had any concerns, they should share them with their hospital, where tests would be done.