Background. Pregnancy has often been associated with cognitive deficits, but results are equivocal and little is known about how these deficits progress with time.

Method. In the present study, the cognitive performance of 57 pregnant women was compared with that of 50 non-pregnant women matched for age and education, using a well-validated neurocognitive test battery at weeks 14, 17, 29, and 36 of pregnancy, and 32 weeks postpartum in the pregnant group and at comparable times in the non-pregnant group.

Results. Memory encoding and retrieval, as assessed with a word learning task, were significantly lower in the pregnant group than in the control group. This difference was still present at 32 weeks after delivery. The two groups did not differ in complex speed of information processing at any of the test moments; however, general speed of information processing was significantly compromised during early motherhood (week 32 postpartum).

Conclusion. Thus, memory performance is poorer during pregnancy and early motherhood, and general speed of information processing is slower during early motherhood.