Pregnancy Planning and Its Association with Autism Spectrum Disorder and Other Developmental Disabilities: Findings from the Study to Explore Early Development

Background: Nearly half of all U.S. pregnancies are unintended at the time of conception. Previous studies demonstrate that women who have unintended pregnancies are more likely to delay prenatal care, smoke and drink during pregnancy, lack daily supplemental folic acid intake prior to pregnancy, and experience certain adverse perinatal outcomes such as preterm birth. Whether pregnancy planning is associated with risks for longer-term developmental disability (DD) outcomes such as autism spectrum disorder (ASD) is not well studied.

Objectives: To examine associations between pregnancy planning and the risk of ASD and other DDs.

Methods: Data for this analysis were obtained from the Study to Explore Early Development (SEED), a multi-site case-control study of ASD risk factors in children ages 30-68 months in 2007-2016. Study groups were children with ASD, children with other DDs, and population-based control children (POP). At enrollment, all children were screened for ASD symptoms with the Social Communication Questionnaire (SCQ); children with a positive screen and/or previous ASD diagnosis underwent further in-person assessments to determine final case status. Children with a DD who had a positive SCQ screen but did not meet ASD case criteria were classified as DD with ASD symptoms. Risk factor data were obtained via maternal telephone interview that included a pregnancy planning question (“At the time of your pregnancy were you trying to get pregnant?”). Mothers who responded yes were scored as having planned their pregnancy. We examined associations between pregnancy planning and 1) ASD (n=1275), 2) ASD or other DD with ASD symptoms combined (n=1743), and 3) DD without ASD symptoms (n=1212) (each vs. POP group [n=1716]). We computed odds ratios adjusted for maternal age, education, parity, and child sex (aORs) and 95% confidence intervals via logistic regression. We repeated analyses in a restricted sample that excluded participants who had certain health outcomes/behaviors possibly in the causal pathway: preterm delivery, multiple birth, pregnancy complications (hypertension, diabetes), smoking just before or during pregnancy, and no folic acid intake just before or during pregnancy.

Results: Initial analyses indicated differential associations by race-ethnicity; we thus conducted subsequent analyses within race-ethnicity strata. Among non-Hispanic white (NHW) mothers, 61.7%, 62.1%, 73.5%, and 80.1% in the ASD, ASD/DD with ASD symptoms, DD without ASD symptoms, and POP groups, respectively, reported they planned their pregnancy. Additionally, after adjustment, pregnancy planning was inversely associated with both ASD (aOR=0.67 [0.54-0.84]) and ASD/DD with ASD symptoms (aOR=0.71 [0.56-0.91]) but not DD without ASD symptoms (aOR=0.94 [0.76-1.17]). Restricting the sample to pregnancies without various health risks or adverse outcomes did not attenuate the findings. In other race-ethnicity groups (non-Hispanic black, Hispanic, and Asian mother-child pairs), pregnancy planning was less common than for NHW mother-child pairs and was not significantly associated with any ASD or DD outcomes.

Conclusions: Our findings suggest an inverse association between pregnancy planning and ASD in NHW children that is not explained by selected demographic, health behaviors, or pregnancy outcomes. Further research is needed on the health and/or behavioral characteristics underlying the observed association and the reasons findings varied by race-ethnicity.