Six recent stillbirths in Ireland have been linked to coronavirus-related infection of the placenta, according to latest figures.
A total of seven cases of coronavirus-related placentitis have been reported; six stillbirths and one case in which the baby was born safely after emergency intervention.
In light of the new evidence, officials are considering whether to strengthen the virus-related advice for pregnant women, particularly in relation to attendance at workplaces.
Last month, the National Public Health Emergency Team reported four cases of placentitis resulting in stillbirth, after they were identified by hospital pathologists.
Two further stillbirths linked to the condition have since been reported, Prof Peter McKenna, director of the HSE national women and infants programme, confirmed.
Since the original reports, perinatal pathologists have “hardened their opinion” and are “more certain” about the link between the condition and the disease, he said.
The new evidence of a risk to the foetus “puts a different slant on things”, he said. “This shows it is more important than ever that women avoid contracting Covid when they are expecting.”
Pregnant women who have had Covid-19 need to be followed up carefully, with any indicators of foetal distress taken “very seriously”.
Prof McKenna said he had changed his mind about the risk to pregnant women in the workplace as a result of the growing evidence of placentitis. While no decisions have been made, discussions have taken place with occupational health doctors about updating the advice for this group.
Dr Cliona Murphy, chair of the Institute of Obstetricians and Gynaecologists, described the cases as a "mixed group" in terms of their experience of the disease. Some had been quite sick at the time of infection but others had only mild symptoms or none at all.
The institute has been in touch with the Royal College of Obstetricians and Gynaecologists (RCOG) in the United Kingdom about the findings.
The college told The Irish Times it was aware of reports of a “proposed association between Covid-related placentitis and a small number of stillbirths in Ireland”.
“We are monitoring the situation in the UK along with colleagues in pathology, but as yet this potential association has not been observed here or, as far as we’re aware, overseas,” according to RCOG vice-president Dr Pat O’Brien. “Further studies are needed to see if this phenomenon is real.”
The seven cases of placentitis observed in Ireland amount to about a third of all known cases globally.
Asked why the condition has not been observed in other countries at the level identified in Ireland, Prof McKenna said it would have been “more convincing” if more cases had been identified elsewhere “but the fact that highly trained Irish professionals have reported it is of note”.
Aside from healthcare workers, very few pregnant women have to date received a vaccine dose.
“There could be an argument to say they should be given greater priority in the vaccine rollout,” Dr Murphy said, similar to that accorded to other at-risk groups.
Prof McKenna expressed scepticism about prioritising pregnant women for vaccination. “If it has taken 15 months to find out Covid has this adverse effect on pregnancy, it’s very difficult to say after three or four months that a vaccine will not have an adverse outcome.”
The institute is preparing fresh guidance on the condition for its members, according to Dr Murphy, while an update from the Faculty of Pathologists is also expected.
While the number of pregnant women requiring critical care this year has risen this year, this is thought to be a consequence of the massive surge in cases after Christmas.