This topic has been making its rounds for awhile now. Periodically whether on Twitter or via email I get asked this exact question. Anecdotally, the numbers of babies in the NICUs across many units in Canada seem to be lower as estimated by various Neonatologists. The question is whether this is real or not and without national data it is tough to say for sure. This week though a research letter came out of the UK entitled Change in the Incidence of Stillbirth and Preterm Delivery During the COVID-19 Pandemic. The authors compared two time periods at a single centre ; St George’s University Hospital, London in 2 epochs: from October 1, 2019, to January 31, 2020 (preceding the first reported UK cases of COVID-19), and from February 1, 2020, to June 14, 2020. Specifically they wanted to look at the rate of stillbirths and preterm births during these two time periods.
What did they find?
There were 1681 births in the prepandemic period and 1718 births during the pandemic. There were no differences in maternal characteristics before and after so presumably if there is a difference in rates of stillbirth and preterm birth it might be the influence of the pandemic. As it is an observational study though it certainly is possible that unmeasured factors are different in the groups but let’s give them the benefit of the doubt.
The rate of stillbirth was up and by a significant margin but the rate of preterm birth was not. There certainly was a trend though towards an increase in preterm delivery prior to 34 weeks. While I don’t know what the cause of all this is for sure it sure is fun to speculate.
Possible reasons for higher rates of stillbirth
- It has been documented that rates of perforated appendicitis in our own centre increased during the pandemic. As the population became frightened of leaving the home, more and more people waited longer to go to the hospital to seek care. I can’t help but wonder if the same thing may have happened here. Might the pattern of seeking care by women for decreased fetal movement shifted ever so slightly? What about the frequency of prenatal visits? In Manitoba a COVID modified approach was done with fewer visits than normal. It certainly is possible that women by having fewer visits could have in some cases missed clinical findings that might have alerted a midwife or obstetrician to a reason to deliver early.
Possible reasons for a decline in preterm birth
- The authors here did not find a difference but in fairness out of the number of pregnancies the number of preterm births would have been about 10% so difficult to really find a difference. Given that under 34 weeks showed a trend to a lower number let’s assume that there might be a difference (or not).
- At least in terms of the perception of lower rates, this might be a case of confirmation bias. One of my colleagues who initally sent me an email from another institution two weeks later sent another that said “I thought we were seeing lower rates and now we are packed to the rafters”. It could well be that we are all noticing when the census is low and not paying attention to the times when it rises. Every time the numbers drop it seems to confirm our suspicions.
- It wasn’t from people choosing to delay family planning as it was too early to see a change in birth rate. I do worry though that we may see declining admissions in the latter part of the year and then a “boom” when a vaccine is produced as families once again choose to conceive. This happened similarly during the Zika epidemic in Brazil.
- It could also be that the finding is real. During the pandemic essentially all pregnant women went on extended rest. Instead of dealing with stressful daily tasks like battling traffic, being late for work and working altogether they were told to stay at home. Financial stress could have then been a factor but at least in Canada the government provided $2000 a month to offset the job losses. It is quite possible at least in my mind that an extended period of rest could have truly led to less preterm birth.
The next step I imagine will be for larger organizations such as the Public Health Agency of Canada to publish their data on this and see what happened across Canada during this period. When we are able to look at tens of thousands of pregnancies we will have enough numbers to drill down whether there has been a change for our smallest infants or not.