Endocrine Abstracts

Background: The influence of the hypothalamic pituitary adrenal axis is not limited to reproduction. Female sex steroids influence learning and memory and the neurobiology of brain regions involved in memory processing such as the hippocampus. Pregnancy allows overriding of regulatory feedback loops leading to elevation of endogenous serum hormone levels, depending on concentration; oestradiol can be either neurologically protective or toxic. This investigation aims to increase understanding of sex steroid influence on memory and attention during pregnancy.

Method: Participants are tested each trimester and at three months following birth, a non-pregnant control group are being tested following the same methodology. Working and spatial memory, attention and planning ability are being examined using the Cambridge Neuropsychological Test Automated Battery, a computer based assessment tool. Demographic, mood and general health data are collected at each session and verbal intellectual ability is assessed using the national adult reading test (NART). Steroid/peptide analysis will be performed when collection is complete and results correlated with cognitive outcomes. Data were analysed using SPSS version 16 and found to be normally distributed. Independent t-test compared antenatal/postnatal and control group scores for each test session outcome measure. The study received ethics approval.

Results: Initial data suggest spatial recognition memory was similar between groups during the first trimester, however there was a significant second trimester antenatal group deficit (antenatal group n=17, control group n=23, P=<0.001), the difference was not significant in the third trimester (antenatal group n=13, control group n=21, P=0.08) or following birth (postnatal group n=10, control group n=18, P=0.08). Spatial planning differed, but not significantly between groups, antenatal group mean initial thinking time was less and subsequent thinking time greater than the control group across all test sessions, possibly indicating subtle steroid induced processing effects, reflected by antenatal group impulsivity in task planning. Group NART, age, mood and general health were not significantly different.

Conclusion: Initial data support the hypothesis that pregnancy adversely affects performance of certain cognitive tasks, specifically spatial planning and spatial memory.