BackgroundIn the context of the SARS-CoV-2 pandemic, consultations and pregnancy monitoring examinations had to be reorganised urgently. In addition, women themselves may have postponed or cancelled their medical monitoring for organisational reasons, for fear of contracting the disease caused by SARS-CoV-2 (Covid-19) or for other reasons of their own. Delayed care can have deleterious consequences for both the mother and the child. Our objective was therefore to study the impact of the SARS-CoV-2 pandemic and the first lockdown in France on voluntary changes by pregnant women in the medical monitoring of their pregnancy and the associated factors.MethodsA cross-sectional study was conducted in July 2020 using a web-questionnaire completed by 500 adult (>18 years old) pregnant women during the first French lockdown (March-May 2020). A robust variance Poisson regression model was used to estimate adjusted prevalence ratios (aPRs). ResultsAlmost one women of five (23.4%) reported having voluntarily postponed or foregone at least one consultation or pregnancy check-up during the lockdown. Women who were professionally inactive (aPR=1.98, CI95%[1.24-3.16]), who had experienced serious disputes or violence during the lockdown (1.47, [1.00-2.16]), who felt they received little or no support (1.71, [1.07-2.71]), and those who changed health professionals during the lockdown (1.57, [1.04-2.36]) were all more likely to have voluntarily changed their pregnancy monitoring. Higher level of worry about the pandemic was associated with a lower probability of voluntarily changing pregnancy monitoring (0.66, [0.46 -0.96]).Conclusions Our results can guide prevention and support policies for pregnant women in the current and future pandemics.