The effects of pregnancy on memory: recall is worse but recognition is not

Women who are pregnant frequently complain of memory problems. Past research suggests that pregnancy is associated with a measurable decline when memory is tested using free recall but not when memory is tested using recognition. However, no prior studies on recognition memory tested performance across two time periods (e.g., pregnant vs. postpartum). A repeated measures design has greater power than a between-subject design to detect any difference in recognition memory performance that might exist. We administered a standardized memory test to 37 women during pregnancy and then again during the postpartum period 3 to 12 months later. Our results show that during pregnancy free-recall performance was somewhat worse (in agreement with prior research) than postpartum but that recognition performance was not worse and was, if anything, slightly enhanced. These results weigh against a purely biological explanation of the memory difficulties associated with pregnancy and instead point to a strategic explanation. In particular, the results suggest that when women are pregnant they rely more on item-specific processing (which can enhance recognition) but when they are no longer pregnant they rely more on relational processing (which enhances recall).