Introduction There is a lack of epidemiological studies on early social and biological environmental factors, which may have an effect on development during childhood. The aim of this life-course cohort study is to explore the association between maternal gestational factors, by focusing on hypertensive disorders, and mild cognitive limitations (MCL, intelligence quotient, IQ 50–85) in the offspring.

Study population and Methods An 11.5 year follow-up study of the Northern Finland Birth Cohort 1986 (NFBC 1986). The study included 8847 singleton children, whose IQ was not below 50. 198 children had MCL. Maternal gestational hypertension (GH) was defined as de novo hypertension arising after mid-pregnancy in previously normotensive mother (systolic blood pressure of ≥140 mm Hg, diastolic of ≥90 mm Hg). Data were collected from maternal healthcare centers to antenatal clinic records. Assessment of the child's intellectual level was based on psychometric test results collected from multiple sources.

Results In multivariate analyses, maternal GH (OR 2.37, 95% CI 1.44 to 3.89) and pre-pregnancy obesity (OR 2.20, 95% CI 1.24 to 3.89) were independent risk factors associated with MCL in addition to high parity, familial socio-economic status lower than professional and small birth weight for gestational age of the newborn.

Conclusions Besides factors indicating adverse maternal health and socio-economic status during pregnancy, also maternal GH should be considered as one of the early risk factors, which may predispose to impaired cognitive development in childhood. However, replication study is needed for delineating the association between maternal GH and MCL in the offspring.