How Pregnancy Changes the Female Brain

Pregnancy is a complex and delicate process involving numerous aspects of female anatomy and physiology. During the last decades, science has uncovered several previously unknown effects on the brains of women during and after gestation. Some of these effects now provide clues that could help understand psychological and cognitive symptoms often experienced as a result of pregnancy, such as pregnancy-induced brain fog or even postpartum depression.

Brain tumors: Scientists still don’t understand what exactly causes meningiomas – a type of relatively common benign (usually asymptomatic) brain tumor. It has been observed that their occurrence is more frequent among pregnant women. In 2012, a report authored by researchers from the Washington University School of Medicine (published in the official journal of the Congress of Neurological Surgeons) revealed that the higher rates of symptomatic meningiomas among pregnant females are likely caused by “hemodynamic changes.” Scientists studied extensive medical records from the university and identified 17 cases of women who were operated for symptomatic or fast-growing meningiomas during or shortly after their pregnancies.

By studying these cases, researchers discovered that these tumors were unlike those of non-pregnant females because they had an abnormally large amount of blood vessels. This ultimately suggests that the rapid growth of these tumors in pregnant women is triggered by the natural changes in blood flow during pregnancy.

Brain shrinkage: Possibly intertwined with the above phenomenon — and the cognitive symptoms associated with pregnancies — is the fact that the female brain shrinks during pregnancy. This has been scientifically observed for at least two decades. Several explanations have been proposed to explain this phenomenon, but no consensus has yet been achieved. In a recent study that tracked the long-term structural brain changes caused by pregnancy, Spanish scientists discovered that some of the affected regions are responsible for social cognition. They believe that these could be adaptations to the parental requirements of raising a child.

In 1997, the London’s Royal Postgraduate Medical School published the surprising discovery of brain shrinkage for the first time, proposing that it could be causally associated with the frequent memory and concentration problems among pregnant women.

Brain growth: During the months immediately following childbirth, the brain starts to regain its normal size. Some of the regions that benefit from the recovery are the hypothalamus and amygdala. These brain structures play critical roles in the process of interpersonal emotional connections, and scientists believe that the respective increase in grey matter facilitates the strong affective bonding that mothers develop for their babies. The maternal-infant bond provides the psychoemotional drive that enables mothers to assist their babies without stressing over the burden of constantly satisfying the newborn’s calls for attention. Oxytocin receptor deficiencies in these regions of the brain have been linked with the onset of postpartum depression, although sleep deprivation may also play a role.