Due to the controversial effects of mental health disorders during pregnancy on infant health, the present study aimed to evaluate the effect of gestational depression, stress, and anxiety on the growth of offspring at six months of age in disadvantaged communities in South of Iran.

The sample comprised of 470 pregnant women (response rate=98%) who are participated in the Bandar Abbas Pregnancy Cohort study. Maternal mental health was measured by the DASS-21 questionnaire during pregnancy. Data on infant growth was collected based on infant`s growth chart at six months of age. The relative risk of suboptimal infant growth was calculated by Modified Poisson regression models at 5% significant level.

The prevalence of depression, anxiety, and stress was 19.0%, 26.1% and 6.5%, respectively. At six months of age, the mean (SD) of infant`s weight (gram), height (cm) and head circumference (cm) were 7287.30 (1019.85), 63.23 (5.62) and 41.39 (2.70), respectively. Compared to normal mothers, the risk of suboptimal weight at six months of age significantly increased by 71% in mothers who were classified as having depression (Adjusted RR: 1.71, 95% CI: 1.07, 2.09). The presence of anxiety significantly increased the risk of suboptimal height at six months of age by 43% (ARR: 1.43, 95% CI: 1.07, 1.92). There were no statistically significant effects of ‎either depression anxiety or stress on the suboptimal head circumference at six months of age.

Our results showed that mental health disorders of pregnant women might adversely influence the weight and height growth of offspring within the first six months of age. Screening protocols to early diagnose of mental health disorders during pregnancy, and to strict follow up of diagnosed cases postpartum are proposed.