Association of cryptic pregnancy and alcohol consumption with fetal alcohol spectrum disorder: a nationwide population-based study of 5 million women in 2015–2022

Cryptic pregnancy (CP) also known as pregnancy denial remains an underexplored risk factor for FASD. To our knowledge, there is no available epidemiologic data in the scientific literature exploring the association between CP and FASD. This study aimed to examine the association between CP and FASD, isolate other contributing factors, and provide insights to inform more effective prevention strategies. This nationwide study utilized the French hospital database. We included all women aged 18–55 who gave birth to a live singleton after 22 weeks of gestation in France, in 2015–2022 ( N = 5,315,906). To estimate the effect of CP on the risk of FASD on child at 1-year, we performed multivariate Cox models, stratified by alcohol consumption. During the study period, the number of CP doubled, while the rate of FASD remained stable at 0.07%. The rate of FASD was ten times higher in cases of CP compared to non-CP (0.77%vs.0.06%, p < 0.01). Multivariate analysis showed that CP was significantly associated with a higher risk of FAS (aHR = 1.71[1.39–2.09]) along with psychiatric disorders and younger maternal age. After stratifying by alcohol consumption history, CP was highly significantly associated with the risk of FASD in women without a documented history of alcohol use (total CP: aHR = 6.85[5.00–9.37], partial CP: aHR = 3.05[1.63–5.71]). CP seems to be highly associated with FASD. Establishing multidisciplinary support for mothers, particularly young women, even without identified alcohol misuse, as well as developing effective prevention strategies on CP appears crucial to reduce FASD incidence.