Venlafaxine (VLF) is an antidepressant drug often used by pregnant women. Its possible adverse effects on fetal CNS development have not been studied. The present study will fill the knowledge gap.

To assess neurodevelopment of children exposed to VLF during gestation.

Cohort study -controlled, matched, and blinded. Assessment of 5 groups of mother-child pairs: exposed to VLF (n=32) or other SRIs (n=29), healthy controls (n=42), and 2 groups of siblings (n=15). Siblings were unexposed relatives of children from the VLF or ‘other SRIs’ groups. Primary outcome: WPPSI-III Scales of Intelligence. VLF exposed children will be compared with those of children in control groups and their non-exposed siblings.

There were no differences in Full Scale IQ, Performance IQ and Verbal IQ between the VLF and SRIs groups (103+10vs105+12; 102+11vs102+15; 103+11vs105+12), VLF group and their siblings (105+12vs100+8; 102+15vs105+7; 105+12vs95+10), or the the SRIs group and their siblings (103+10vs104+8; 102+10vs104+8; 103+11vs106+12). Healthy controls scored significantly higher than the VLF group and the other 3 groups in Full Scale IQ, Performance IQ and Verbal IQ (P= 0.011; 0.041; and 0.028 respectively).

Preliminary results show that factors such as maternal depression, genetics, and environment (not necessarily the antidepressant) are strongly associated with the child's cognitive abilities. Assessment of siblings helps to verify the impact of these factors and is possibly the strongest evidence in drug safety studies.

Wyeth Pharmaceuticals