Effects of normal pregnancy on maternal EEG, TCD, and cerebral cortical volume

Objective: Pregnancy causes many changes in our body and some of them may affect our ability of learning and memory. We examined the cerebral cortical volume of brain during pregnancy and measured changes in the brain electrical activity and cerebral blood flow. Method: 35 women (20 normal full-term primigravida and 15 non-pregnant women) received the Electroencephalography (EEG) and Transcranial Doppler ultrasonography (TCD). 8 non-pregnant women and 9 primigravida after vaginal delivery underwent brain magnetic resonance imaging (MRI) voluntarily within 24 h. Results: Compared with the non-pregnant, changes were shown by EEG through electrodes of T5, Pz, Cz, T6, F3 and F8. The results displayed increased activity in the central parietal area of pregnant women, while that in the temporoparietal junction decreased. The result of TCD revealed that pulsation index (PI) values of left and right internal and external carotid arteries were asymmetrical, but they all decreased in pregnancy. Atrophy of cortical volume had been found in many brain functional areas of pregnant women. The percentage of atrophy varied between 6.76% and 13.17%. Conclusion: Atrophy of cerebral cortex, changes in cerebral blood flow and neuron electrophysiology may be the physiological basis of the emotional, cognitive changes in pregnant women.