Memory performance in late pregnancy and erythrocyte indices

A previous study in elderly people observed an association between chronologically younger erythrocyte population and memory impairment. The aim of this study was to assess whether a similar shift in erythrocyte population in pregnant women in late pregnancy is associated with changes in memory performance in healthy pregnant women.

Thirty healthy pregnant women were included in a prospective cross-sectional study. Explicit memory and autobiographic memory tests were performed in the late third trimester and 4 months postpartum. Mean corpuscular volume (MCV) was considered the primary predictor variable.

The mean explicit memory recall scores were significantly higher at post-delivery compared to pre-delivery: 8.3 +/- 1.7 and 7.4 +/- 1.4, respectively (P = .015). The difference in mean autobiographic memory test score pre- and post-delivery did not reach statistical significance. A positive correlation between post-delivery explicit memory recall scores and the difference between pre- and post-delivery MCV was detected (r = 0.458, P = .01). The correlation between delta MCV and delta explicit memory recall scores was r = 0.2, P =.311. Pre-delivery autobiographic memory test scores were positively correlated with MCV (r = 0.50, P = .006), mean corpuscular hemoglobin (r = 0.57, P = .001), and mean corpuscular hemoglobin concentration (r = 0.46, P = .013).

The change in erythrocyte population that is present in late pregnancy predicted explicit memory performance after delivery, when it was improved. The younger erythrocyte population that exists in late pregnancy is associated with a better autobiographic memory.