Has lockdown reduced the number of premature babies? This doctor thinks so

Covid-19 restrictions have meant a healthier lifestyle for pregnant women, studies suggest

Mandy Daly still wonders if she hadn't got on to a plane, would she have not gone into premature labour and her daughter not had to cope with the complications of arriving in the world at just 25 weeks and six days.

It is 14 years since she boarded that flight but the “if only . . .” thoughts, with which mothers of pre-term babies are inclined to torment themselves, have never been fully extinguished. Boom-time Ireland was in full flow and she and her husband were flying from Dublin to Cork with Aer Arann for €4.99 “because we could”. In hindsight, she says, “it really wasn’t worth it”.

Knowing she was in labour, Daly got into a car in Cork to go straight back to Dublin. It was before Cork University Maternity Hospital had been built, she says, and she wanted to get back to Dublin’s Rotunda maternity hospital.

We took “a stupid chance”, she says now of that car journey “but we were lucky ultimately”. They got to the Rotunda safely and their daughter did survive but she has ongoing issues. For instance, because she has suffered lung disease, she is a teenager who has been “cocooning like her grandparents” during the Covid-19 pandemic.


No surprise then that Daly took keen interest in findings emerging from the University Maternity Hospital Limerick, about a possible link between lockdown and an apparent dramatic drop in the number of very low-weight babies being born at the hospital. Cofounder of the Irish Neonatal Health Alliance (inha.ie), she is one of the authors of the research paper that has been "pre-published" before being peer reviewed and was reported on in The Irish Times last month.

It found a 73 per cent reduction in the number of very low-weight babies born in the Limerick hospital when compared with the average for the same first four months of the year in the preceding two decades.

News of the study, led by Prof Roy Philip, consultant paediatrician and neonatologist at the Limerick hospital, has attracted a lot of international interest, not least because, coincidentally, a much larger Danish study, pre-published just days earlier, also flagged a huge drop in the extremely premature birth rate.


In Denmark, researchers looked at national births data for their lockdown period of March 12th to April 14th and compared it with that of the same period over the previous five years. They found a 90 per cent reduction in the birth rate of extremely premature babies (below 28 weeks) when compared to the stable rate of previous years but there was no significant difference for other gestational ages of births during that time.

So, what are we to take, if anything, from these headline findings? Did the Covid-19 restrictions really bring on a healthier lifestyle that was more beneficial to pregnant women than normal routines allow and, if so, what are the implications of what the Limerick study calls “nature’s experiment”?

While stressing that the paper is still under peer review, Prof Philip tells The Irish Times that it was an “interesting drop” that was observed and one which has continued since the cut-off date for their research at the end of April. He did wonder whether or not to issue it as a pre-publication but says he is glad he did because he is learning a lot from the response around the world.

“I have plenty of new ideas and it has turned into almost ‘crowd research’,” he says. “We are now analysing if this is a repeatable trend elsewhere.” At the time of talking, there are seven countries involved in that research but he thinks more may join in.

The idea for the study came to Prof Philip through being absent from the hospital. Normally he has to make the case for spending on a very costly human breast milk fortifier for each baby born below 1kg that needs it, yet there were no requests for him to sign off on these while he was away.

Normally the Limerick hospital has between 40 and 50 babies a year born at a weight below 1.5kg. Up to near the end of June, they had only had four or five

On his return after more than two weeks, “I asked why did nobody contact me so we could get it approved even though I was away and they said there was nobody to get approval for,” he recalls.

“What do you mean?” he asked. “There were no babies,” he was told. That is what triggered him to start looking at what was going on.

“The more I looked into it, the more fascinating it became, because nobody had a clue why these babies are not here. Nobody was dying, they were not ending up in still birth; why was this happening?”

Normally the Limerick hospital has between 40 and 50 babies a year born at a weight below 1.5kg. Up to near the end of June, they had only had four or five, he reports. Usually there are 10-15 babies in the extremely low birth weight category every year and up to the last week of June, they had only one – born after the study, he says.

Possible reasons

The study suggests 10 possible reasons while the lockdown might have an impact on the rates of pre-term babies being born, ranging from less stress to reduced exposure to tobacco and illegal drugs. It seems to be “truly multifactorial”, he says, and he doesn’t know which might be more important than another.

However, personally, he believes a reduction in maternal stress could be a contributing factor. He is thinking of how, even if still working from home, the fact of no longer having to commute, morning and evening, could help. There would probably be the opportunity for better nutrition at home too.

In many cases they would have had their partner at home, who might have been an extra support. Any other children in the household were no longer bringing infections home from creche and schools. We also know from studies all over Europe that environmental pollution was significantly down.

He will be interested to see what figures might come out of the other 18 maternity units in Ireland. The only reason they could do the research so quickly in Limerick was because they had easy access to two decades of previous data and he is not sure other units would be in the same position.

The master of the National Maternity Hospital (NMH) in Holles Street, Prof Shane Higgins, sees no similar trend when looking at January-April data since 2017. In fact, the hospital's rate of pre-term births, as defined as less than 37 weeks, has gone up from 7.4 per cent of all births in 2017 to 9.3 per cent this year.

He also says that “since January to April doesn’t really correspond with lockdown, as that did not really happen until the beginning of March, I am struggling with how that might have had a significant impact on pre-term births”. What’s more, he says, such a rate will always fluctuate from year to year.

As for the specific categories of very low weight babies covered by the Limerick research, the percentage of babies born weighing less than 1.5kg at the NMH in the corresponding period this year was almost identical to 2017, being 1.9 per cent in 2017 and 2.1 in per cent 2020. In the case of babies less than 1kg, it went from 0.7 per cent in 2017 to 1.3 per cent in 2020.

“I am not dismissing this study,” Higgins says. “I am just saying you are not giving it long enough to really appreciate what benefits there might have been.”

Consultant neonatologist Dr John Kelleher, who is head of the Coombe Hospital's neonatology department, reports a slight decrease in the total number of extremely preterm (born under 30 weeks) babies delivered there between January and June this year. However, overall birth numbers at the Coombe Hospital have been decreasing since 2018.


Between 2012 and now, the average annual number of extremely preterm and/or very low birth weight (under 1.5kg) newborns at the Coombe for the months of January to June is 55, he reports. Whether the slight fall in numbers over that period this year “is, or is not, in any way associated with the Covid-19 pandemic and changes to lifestyle of expectant pregnant mothers is at best speculative”, he suggests. With a lack of good peer-reviewed published epidemiological data to substantiate such an association, he adds, “such an observation may be a chance finding at best”.

The Rotunda has no comparable figures as regards pre-term babies, according to a hospital spokeswoman.

Philip believes that if the findings from Limerick and Denmark are replicated elsewhere, it will pose interesting questions about lifestyle advice for pregnant women. He is waiting for reports to come from centres that are “mimicking our population”, ie where most women are working outside the home and have factors such as stress and pollution to contend with.

The Danish researchers also believe the 90 per cent reduction they have seen is due to the same factors

There would be “huge economic implications”, he says, if the rate of very low weight births could be reduced. Some of the babies born at 23 or 23 weeks may live in a neo-natal until for up to three months “and the cost of that is massive”. That’s before you even start counting the cost of a possible lifelong involvement of each baby with the health services due to complications arising from prematurity.

What is his advice to pregnant women, or women planning pregnancy, when looking at this?

“I really don’t know, I am learning,” he replies. However, he believes there is no harm in recommending the avoidance of stress, particularly unnecessary work-related stress, also pollution and exposure to infection agents where possible.

The Danish researchers also believe the 90 per cent reduction they have seen is due to the same factors, “but that is all we can say at the moment”. What lockdown seems to have taught us, he adds, is that “the biology of nature is slightly different to the sociology of nature”.

Less stress is beneficial for us all, including pregnant women, says Higgins. They often see at the NMH how slowing down can help. “We have patients who have hypertension and we think we are approaching the point where we might have to deliver them. We admit them to hospital and within the space of three or four days, when they are on bed rest and they are relaxing, their blood pressure becomes much easier to control.”

Slow down

In the normal course of life, there are pregnant women who may not have the opportunity to slow down, but “we talk in terms of a balanced lifestyle: healthy diet, a certain amount of activity and exercise and rest. That balance would probably vary from one patient to the next,” he adds, “but that’s the generic advice we give.”

Krysia Lynch, chairwoman of the Association for Improvements in the Maternity Services (AIMS) – Ireland, has observed an attitudinal change among some pregnant women who have been not been in their workplace since the start of the coronavirus restrictions. They're resolving to start their maternity leave earlier and more of them discussing trying to stay at home as long as possible with their baby, rather than rushing back to work.

“I am talking about women who have quite intense jobs and always felt the pressure to return, whereas now they don’t feel that.” Being at home during the pandemic seems to have shifted perspectives and she has no doubt being removed from the physical, environmental and emotional stresses of work has an effect.

“If nothing else, I would like to see this study looked at in terms of policy, in terms of maternal health – physical and mental. We just assume pregnant people are the same as non-pregnant people – they just have a bigger tummy.”

I think this conversation has started. There is definitely a case for a national audit

It begs the question, she adds, have we been making incorrect presumptions about how pregnant people should be treated in the working environment?

The vast majority of pre-term births are due to rupture of membranes, infection or pre-eclampsia, says Daly. For some there may be a genetic pre-disposition, as she suspects was a factor in her case with a family history, “but then I made it worse by getting on a plane”. Had she been better informed, maybe she wouldn’t have taken that trip.

Daly was involved in a 2010 report led by Dr John Murphy from the NMH, which identified five things that needed to be done in Ireland to improve the neo-natal field.

“One of them was looking at awareness because people weren’t aware of what causes pre-term births and one of the big factors we looked at was lifestyle.”

National audit

She believes there is still a lot of education to be done and while there is nothing definitive yet about the Limerick report, “I think this conversation has started. There is definitely a case for a national audit.”

As things stand, her advice to newly pregnant or those planning a baby is to pay more attention to social-environmental factors.

“It is worth looking at your own lifestyle and modifying it, as this data seems to pointing towards that fact that these factors may be having an impact on very low birth weights in pre-term births and they are the ones that have the biggest challenges.”

Anything you might be able to do during pregnancy to mitigate that, she adds, “is a very small price to play”.