Available online 26 January 2024

Author links open overlay panel, , , ABSTRACTPurpose

A recent meta-analysis finds reduced risk of preterm birth (PTB; <37 weeks gestational age) during the initial stage of COVID-19 in which infection rates remained relatively low but many societies imposed restrictions on movement. None of this work, however, examines sex-specific responses despite much literature on other ambient “shocks” which would predict male sensitivity. We use a conception cohort approach to explore potential sex-specific PTB responses in France, a country which imposed a lockdown in Spring 2020.

Methods

We applied interrupted time series methods using national data in France for 207 weeks among 1,403,284 males and 1,341,359 females conceived from 19 Jan 2016 to 6 Jan 2020.

Results

For males in utero, the 1st COVID-19 societal lockdown corresponds with a -0.60 per 100 conception reduction in PTB cases per week, for 12 consecutive weeks (95% confidence interval [CI]: -.36, -.84). For females in utero, the PTB reduction is smaller (-0.40 reduction per 100 conceptions, for 10 consecutive weeks, 95% CI: -.15, -.61). A formal test of sex differences in the PTB response indicates a stronger reduction in male (vs. female) PTB during the lockdown (p=.001).

Conclusions

Explanations for the counterintuitive reduction in PTB during COVID-19 among cohorts in utero during Spring 2020 should consider mechanisms that disproportionately affect males.

Section snippetsINTRODUCTION

Ambient shocks such as terrorist attacks, earthquakes, and sudden economic contraction increase the risk of adverse birth outcomes among gestations in utero at the time of the shocks [1], [2], [3], [4]. The initial onset of the COVID-19 pandemic in many high-income countries elicited increases in depression, anxiety, and substance use which mirrored population responses to prior unexpected shocks [5], [6], [7]. A recent meta-analysis of 63 studies during the initial months of the pandemic,

Data and Variables

French hospital discharge data in the Programme de médicalisation des systèmes d’information (PMSI) serve as our source dataset. We accessed these data through the French National System of Health Data (Système national de données de santé [SNDS]). We created a linked mother-baby cohort from delivery and birth hospitalizations using data from 2016 to 2020 in Metropolitan France. Delivery hospitalizations include all deliveries occurring from 22 weeks of gestation and over while birth

RESULTS

We analyzed 2,765,723 singleton and 44,401 twin conceptions over 207 weeks, of which 51.1% of singletons and 50.1% of twins were male. The PMSI data contain information on 1,414,334 male and 1,351,389 female singleton conceptions, which averages to 13,361 singleton conceptions per week over the 207 study weeks. The incidence of singleton PTB is greater for males (average: 5.6 per 100 conceptions; see Figure 2) than for females (average: 4.8 per 100 conceptions; see Figure 3).

Inspection of the

DISCUSSION

Our sex-specific analysis of PTB in France during the initial COVID-19 societal restrictions in Spring 2020 makes several contributions. First, whereas PTB fell below expected levels in both male and female singletons, male PTB fell more steeply, and for more conception cohorts, than did females. Second, declines in PTB among male twins (but not females) also occurred, albeit for only one weekly conception cohort that was “scheduled” to deliver preterm for the first six weeks of the Spring 2020

CRediT authorship contribution statement

Fresson Jeanne: Data curation, Methodology, Resources, Writing – review & editing. Zeitlin Jennifer: Data curation, Resources, Supervision, Writing – review & editing. Bruckner Tim Allen: Formal analysis, Investigation, Methodology, Project administration, Supervision, Writing – original draft. Huo Shutong: Methodology, Visualization, Writing – review & editing.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

The authors thank Alice Bergonzoni for her assistance preparing data tables for this study.

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© 2024 Published by Elsevier Inc.