Background: Although smoking in pregnancy has well known deleterious effects, about 50% women who smoked out of the pregnancy continue to smoke while pregnant. The main is to study changes in smoking in pregnancy during covid-19 pandemic.
Methods: We compare two cohorts of pregnant women: one recruited in 2018 (pre-pandemic cohort) and one recruited from March 2020 on (pandemic cohort).
Results: The percentage of women who smoked decreased from 13% in the pre-pandemic cohort to 8% in the pandemic cohort (p<0.001). This step-down was similar in all age groups and both employed and unemployed/no active women. Among women in the pandemic cohort, those whose pregnancy began after March-2020 (when the pandemic was declared) reported 1% smoking prevalence, which is much lower than smoking prevalence in women whose pregnancy began before the pandemic was declared.
Conclusion: Smoking was less frequent in pregnancies during the covid-19 pandemic and even less frequent in women whose pregnancy began after the pandemic was declared. The effect that lockdown, stay-at-home orders or healthier behaviour habits could have had on smoking in pregnancy would require further research.
Trial registration: The study was approved by the Clinical Research Ethics Committee of Cantabria (reference: 2020.174).