Flattening the Covid-19 curve during the initial outbreak saved lives. While the United States did not do a “lockdown” the way China did, life as we know it changed in March of 2020. But by May and June, states were opening back up, some more than others.
Those early days of the pandemic changed how we live in countless ways, some large and some small, some temporary and some lasting.
Here’s an interesting one. I was reading a report from the CDC over the weekend that I hadn’t seen before. Turns out that the rate of twins being born went down during the pandemic. Who knew? (The CDC, it turns out.)
Some of this is thought to be due to decreases in fertility treatment early in the pandemic, but not all. I was curious whether temporary suspensions of fertility treatment in the spring of 2020 had made a noticeable impact on birth rates in the fall of 2020 and winter of 2021. So I looked under the hood of our national birth database.
By and large, there were not major changes in birth rates 9-11 months after the shelter-in-place period in the US. (There may have been a 5% decrease, but I’m basing this off of some rudimentary modeling I did over the weekend, and without a more rigorous approach, I wouldn’t bet the farm on it.)
But there’s one group in whom the birth rate absolutely plummeted 9-11 months after Covid-19 erupted in the US: women over the age of 40. In the late fall of 2020 and winter of 2021, there were several thousand fewer live births than normal—though by late 2021, a small rebound seems to have evened things out.
Something stood out to me, though: The older the mothers, the more pronounced the changes. Let’s look at the data and then discuss them.
Live births to older mothers plummeted 9 months after the shelter-in-place period in the United States.
Take a look at monthly live births in the United States to born to mothers age 45 and up in the decade from 2012-2021. To make the point, I modeled the number of expected births starting in 2019 and extending through the end of 2021.
From 2019 through February 2020, the number of births (blue line) was around 2.3% lower than my modeling would have predicted (yellow line). That’s basically just noise in this case. But later in the year and early 2021? That’s not noise. That’s a genuine and impressive increase. In December 2020, and January 2021, births to mothers ages 45 and older were much lower than anticipated (40% and 41% respectively).
If we isolate the data for mothers ages 50 and up (yes, in recent years there have been around 1,000 births per year in the US to women ages 50 and up), the effect is even greater.
In this age group, live births fell 61% and 52% from expected counts in December 2020 and January 2021. Note also that I’ve highlighted another unusually quiet month for births in this age group that occurred back in September of 2016. On a hunch, I looked back at Google searches for the Zika Virus. Interest in that disease, which can cause birth defects (albeit rarely), began taking off right around 9 months prior to that sudden dip in births. I’m not sure this finding has ever been discussed in public—and I’m not even sure it has been described in the medical literature! (If I’m wrong, please tell me.)
Why did this happen?
Infertility becomes more common with age. By the mid-40s, a majority of births are aided by fertility treatments of one kind or another. When Covid-19 broke out, fertility experts advised that the initiation of fertility treatments be halted for a time. By May, the same experts advised a cautious return to the initiation of fertility treatments. For older women wishing to become pregnant, the short-term effects of this policy were noticeable 9 months later. (Meanwhile, for the Zika dip, a short-term scare seems to have abated after initial panic subsided.)
What will we do next time?
I’ve been spending a lot of time thinking about “the next pandemic” lately. My worry is that people mistakenly think that many measures we took did not work. They’re often wrong, but that leaves us vulnerable to a very, very bad set of outcomes in the future. Still, I’ve been mulling over what we can do better next time.
There will be little things that we’ll want to keep doing, if it is safe. (The less we ask of people, the more they’ll do the things we do ask.) Stopping fertility treatments was probably a necessary measure early in the Covid-19 pandemic. But if we’d had rapid antigen tests at the time (instead of more than a year later), medical visits for reasons like infertility could have safely continued—that is, when the hospitals and clinics were not full of Covid-19 patients. With test (and masks), outpatient visits for things like hormone injections and testing could have probably safely continued. Hopefully, if we have another pandemic, we’ll have tests earlier. Indeed, better mitigation is not always more mitigation. The more we do right early on, the less disruptive the next pandemic will be.
We should be more honest next time, tell the truth about everything, even if you think it will make people comply less, because the credibility of institutions is too important, the day we learned that you could still transmit and get Covid even if your vaxed should have been the day we ended all mandates, I remember it vividly, the Providence-town outbreak was among a fully vaxed community, when institutions aren’t honest, even for honorable reasons, it makes people cynical like it was all a big money grab by big pharma,
A leading jewelry chain CEO (Signet), in explaining a downturn in revenue, stated that marriages will be down to 2.4m this year from a more typical 2.8m (and I note that David's Bridal also recently declared bankruptcy). This is attributed to the fact that couples tend to marry 3-3.5 years after meeting and far fewer connections were made during the first half of 2020. Birth rate impact, if any, might show in 2024 and 2025.