Secret births (a regulated situation in France where a woman does not reveal her identity and wishes for the newborn to be made a ward of the state) were excluded. Previous ENPs followed similar protocols. Age-standardised seroprevalence decreased from 55.0% in 1995 to 33.7% in 2016. Among French women, significant associations MAPK3 with age, Paris and south-west regions persisted across all MS417 ENPs. Conclusion Higher prevalences in older women may reflect a higher past risk of exposure while persistent geographical differences may reflect dietary or environmental differences. seroprevalence among pregnant women continues to fall and will impact screening effectiveness. This warrants a comprehensive review to determine the appropriate future of prevention in France. infection, and to compare the results with previous ENPs. Methods Study population and national MS417 perinatal survey The ENP is a periodic cross-sectional survey of births in France conducted in 1995, 2003, and 2010. The methodology is detailed elsewhere [17-19]. In brief, in the 2016 survey, all births greater than 22 weeks gestation and/or a birthweight over 500?g in all public and private maternity units between 14 and 22 March 2016 were eligible for inclusion. A face-to-face interview post-delivery collected information on a range of sociodemographic and pregnancy-related factors while data collectors extracted specified medical information from clinical records, including toxoplasmosis-related data. Stillbirths, terminations of pregnancy (TOP), births by minors ( 18 years), or where the mother was medically unfit to participate, were excluded from full participation. In such a case, or in the case of refusal to participate, a minimum dataset of non-identifying birth-related indicators was collected from clinical records as authorised by the national data protection agency. Secret births (a MS417 regulated situation in France where a woman does not reveal her identity and wishes for the newborn to be made a ward of the state) were excluded. Previous ENPs followed similar protocols. Prior to 2016, births to minors and stillbirths were not excluded from full participation. Of note, the overseas department of Martinique did not participate in 2010 due to a lack of personnel, and Mayotte did not participate until 2016, after becoming an overseas department in 2011. Specifically in relation to toxoplamosis, the 2016 ENP included only the serological status based on the last toxoplasmosis test during pregnancy (categorised as: absence of antibodies to present, seroconversion during this pregnancy, or unknown). Previous ENPs recorded the dates of the last negative and the first positive serological tests in the event of a seroconversion. Determination of toxoplasmosis serological status We classified a woman as seropositive if she was documented as having IgG antibodies present or she was documented as having seroconverted during the pregnancy, and seronegative if she was documented as having no antibodies. Of note, analyses of previous ENPs defined a seroconversion only when dates for the last negative and the first positive test were available. Data analysis We included women with a known toxoplasmosis serological status. We calculated the seroprevalence by sociodemographic characteristics and compared differences using chi-squared tests. Univariable and multivariable analysis (UVA and MVA) was undertaken to estimate prevalence ratios (PRs) and evaluate statistically significant factors associated with seropositivity. Due to interactions between age and nationality, we stratified according to self-reported nationality grouped into French women, women from North Africa and women from sub-Saharan Africa (SSA) (categories used in the ENP questionnaire). In the MVA, regions in mainland France were grouped by Zone dEtudes et dAmnagement du Territoire (study and regional planning zone; ZEAT), equivalent to the European Union Nomenclature of territorial units for statistics (NUTS) level 1, and overseas departments were MS417 combined [20]. We constructed the MVA model using a backward stepwise elimination procedure starting with those variables that had a revealed p value of? ?0.01 in the UVA. We used a Poisson model with robust error variance. This model with robust error variance is a recommended alternative to estimating prevalence ratios [21]. The MVA model constructed MS417 for French women was then applied to the other nationality groupings. When interpreting results, we considered estimates with a p value of ?0.05 as significant. Available datasets for the 1995, 2003, and 2010 ENPs included the common variables: serological status, age, gravidity, nationality, level of educational achievement and region of residence. We compared the seroprevalences between ENPs through direct age-standardisation, using females ages 1544 years from the 2014 census as the reference population..