The Long-Term Effects of Maternal Postnatal Depression on a Child's Intelligence Quotient: A Meta-Analysis of Prospective Cohort Studies Based on 974 Cases.

OBJECTIVE: Epidemiologists have explored the relationship between maternal postnatal depression (PND) and the intelligence quotient (IQ) of the resulting offspring, but the results remain inconclusive. This study aims to analyze the literature regarding the association between maternal PND and a child's IQ.

DATA SOURCES: A search of articles in PubMed, Web of Science, and MEDLINE databases from inception to September 2015 was conducted and supplemented by a manual search of relevant reference lists. The following search terms were used: (postpartum OR postnatal OR puerperal) AND (depression OR depressive symptoms OR blues OR dysthymia OR disorders OR psychosis) AND (intelligence quotient OR IQ OR intelligence tests OR intelligence OR cognitive OR cognition) AND (children OR child OR adolescent OR offspring) AND (cohort OR prospective OR follow-up OR follow OR longitudinal).

STUDY SELECTION: Articles exploring the association between maternal PND and IQ of offspring aged 2 years and older were included. A total of 510 records were retrieved.

DATA EXTRACTION: Two authors independently selected eligible studies and extracted data. Three authors assessed the quality of the studies. To explore the associations between maternal PND and full IQ and verbal IQ, random-effects meta-analyses were performed, followed by subgroup analysis of impact on full IQ.

RESULTS: Nine articles were eligible for review. On the basis of the Newcastle-Ottawa Scale, 7 studies were considered to be of high quality. When one study of participants aged 3.8 years was excluded from the meta-analysis, the pooled weighted mean difference of full IQ between the children of PND mothers and non-PND mothers was -4.086 (95% CI, -6.578 to -1.594), and the pooled standard mean difference of verbal IQ between the children of PND mothers and non-PND mothers was -0.361 (95% CI, -0.564 to -0.158). Subgroup analysis showed that the child's age at evaluation, diagnostic method of PND, study quality, and socioeconomic status did not affect the mean difference in full IQ between children of PND mothers and those of non-PND mothers. When the excluded study was included in the meta-analysis, the results did not vary.

CONCLUSIONS: Maternal PND may be a risk factor for a child's lower IQ. More studies of high methodological quality may be needed.