Maternal anxiety, depression, and stress during and after pregnancy are negatively associated with child cognitive development. However, the contribution of positive maternal experiences, such as social support, to child cognitive development has received less attention. Furthermore, how maternal experience of social support during specific developmental periods impacts child cognitive development is largely unknown.

Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC; n = 5784) and the Prediction and Prevention of Preeclampsia and Intrauterine Growth Restriction study (PREDO; n = 420), we investigated the associations between maternal perceived social support during and after pregnancy and child's general cognitive ability at 8 years of age, assessed with the Wechsler Intelligence Scale for Children (WISC). Bayesian relevant life course modeling was used to investigate timing effects of maternal social support on child cognitive ability.

In both cohorts, higher maternal perceived social support during pregnancy was associated with higher performance on the WISC, independent of sociodemographic factors and concurrent maternal symptoms of depression and anxiety. In ALSPAC, pregnancy emerged as a sensitive period for the effects of perceived social support on child cognitive ability, with a stronger effect of social support during pregnancy than after pregnancy on child cognitive ability.

Our findings, supported from two prospective longitudinal cohorts, suggest a distinct role of maternal perceived social support during pregnancy for cognitive development in children. Our study suggests that interventions aimed at increasing maternal social support during pregnancy may be an important strategy for promoting maternal and child well-being.

Maternal depression during pregnancy increases the risk for adverse developmental outcomes in children. However, the underpinning biological mechanisms remain unknown. We tested whether depression was associated with levels of and change in the inflammatory state during pregnancy, if early pregnancy overweight/obesity or diabetes/hypertensive pregnancy disorders accounted for/mediated these effects, and if depression added to the inflammation that typically accompanies these conditions.

We analyzed plasma high-sensitivity C-reactive protein (hsCRP) and glycoprotein acetyls at three consecutive stages during pregnancy, derived history of depression diagnoses before pregnancy from Care Register for Healthcare (HILMO) (N = 375) and self-reports (N = 347) and depressive symptoms during pregnancy using the Center for Epidemiological Studies Depression Scale completed concurrently to blood samplings (N = 295). Data on early pregnancy body mass index (BMI) and diabetes/hypertensive pregnancy disorders came from medical records.

Higher overall hsCRP levels, but not change, during pregnancy were predicted by history of depression diagnosis before pregnancy [HILMO: mean difference (MD) = 0.69 standard deviation (s.d.) units; 95% confidence interval (CI) 0.26–1.11, self-report: MD = 0.56 s.d.; 95% CI 0.17–0.94] and higher depressive symptoms during pregnancy (0.06 s.d. per s.d. increase; 95% CI 0.00–0.13). History of depression diagnosis before pregnancy also predicted higher overall glycoprotein acetyls (HILMO: MD = 0.52 s.d.; 95% CI 0.12–0.93). These associations were not explained by diabetes/hypertensive disorders, but were accounted for and mediated by early pregnancy BMI. Furthermore, in obese women, overall hsCRP levels increased as depressive symptoms during pregnancy increased (p = 0.006 for interaction).

Depression is associated with a proinflammatory state during pregnancy. These associations are mediated by early pregnancy BMI, and depressive symptoms during pregnancy aggravate the inflammation related to obesity.

Synthetic glucocorticoids, to enhance fetal maturation, are a standard treatment when preterm birth before 34 gestational weeks is imminent. While morbidity- and mortality-related benefits may outweigh potential neurodevelopmental harms in children born preterm (<37 gestational weeks), this may not hold true when pregnancy continues to term (⩾37 gestational weeks). We studied the association of antenatal betamethasone exposure on child mental health in preterm and term children.

We included 4708 women and their children, born 2006–2010, from the Prediction and Prevention of Pre-eclampsia and Intrauterine Growth Restriction Study with information on both antenatal betamethasone treatment and child mental and behavioral disorders from the Finnish Hospital Discharge Register from the child's birth to 31 December 2016. Additional follow-up data on mother-reported psychiatric problems and developmental milestones were available for 2640 children at 3.5 (s.d. = 0.07) years-of-age.

Of the children, 187 were born preterm (61 betamethasone-exposed) and 4521 at term (56 betamethasone-exposed). The prevalence of any mental and behavioral, psychological development, emotional and behavioral, and comorbid disorders was higher in the betamethasone-exposed, compared to non-exposed children [odds ratio 2.76 (95% confidence interval 1.76–4.32), 3.61 (2.19–5.95), 3.29 (1.86–5.82), and 6.04 (3.25–11.27), respectively]. Levels of psychiatric problems and prevalence of failure to meet the age-appropriate development in personal-social skills were also higher in mother-reports of betamethasone-exposed children. These associations did not vary significantly between preterm and term children.

Antenatal betamethasone exposure may be associated with mental health problems in children born preterm and in those who end up being born at term.

Although schizotypal traits, such as anhedonia and aberrant perceptions, may increase the risk for schizophrenia-spectrum disorders, little is known about early-life characteristics that predict more pronounced schizotypal traits.

To examine whether birth size or several other early-life factors that have been previously linked with schizophrenia predict schizotypal traits in adulthood.

Participants of the Northern Finland 1966 Birth Cohort Study (n = 4976) completed a questionnaire on positive and negative schizotypal traits at the age of 31 years.

Lower placental weight, lower birth weight and smaller head circumference at 12 months predicted elevated positive schizotypal traits in women after adjusting for several confounders (P<0.02). Moreover, higher gestational age, lower childhood family socioeconomic status, undesirability of pregnancy, winter/autumn birth, higher birth order and maternal smoking during pregnancy predicted some augmented schizotypal traits in women, some in men and some in both genders.

The results point to similarities in the aetiology of schitzotypal traits and schizophrenia-spectrum disorders.