Motherhood changes a woman forever. She is no longer the same person as she was before the pregnancy. Not only her body but also her brain undergoes changes both structurally and functionally. It is the nature’s way of ensuring the survival of the species.

Interestingly some of these changes are not only seen in the biological mothers but also in adoptive mothers who are primary caregivers. The physical cues from the infant forge new neurochemical pathways in the brain that create and reinforce maternal brain-circuits. These changes transform the woman into a highly attentive, motivated, and aggressively protective mother.

Rollercoaster Ride of Brain Changes begins at Conception

Mommy brain’s symptom starts at conception. The brain circuits related to hunger, thirst, and smell see an enlargement to keep the fetus well nourished and to double the volume of blood. The heightened sensitivity to smells helps the mother to guard against consuming anything that may harm the fetus in any way. The surge of progesterone during the first two to four months of pregnancy keeps the brain at rest despite the high production of stress hormone by the fetus and placenta. The role of the stress hormones is to make the mother more vigilant about her safety and nutrition.

Shrinking of Mommy’s Brain

While the heavy concoction of hormones makes the mother more attentive towards her fetus, it also makes her distracted, forgetful and preoccupied. An erstwhile highly efficient woman may struggle to concentrate or remember names. This may be due to the loss of the gray matter in certain regions of her brain.  A new study published in Nature Neuroscience found that shrunken brain areas remain unchanged even after two years of childbirth suggesting permanent nature of the change. The biggest loss of gray matter happens in the front area of the brain responsible for social understanding and interactions. Some scientists have pointed out that bigger is the loss of volume in this region the more a mother is attached to her child.

Formatting the Brain for Motherhood 

Shrinking of the brain, it appears, is a sign of brain refining itself to become more attuned to the needs of the child. But rest assured that loss of gray matter does not connote loss of cognitive power. Rather it is brain’s way of becoming more organized and efficient to face the challenges of motherhood.

Growth of New Brain Circuits

At the birth of the child, a burst of oxytocin(love hormone) in the brain activates new receptors and forges thousands of new connections between neurons. The mother becomes acutely sensitive to the needs of her child. Also, maternal aggression sets in with the resolve to care for and protect this little being. Surges of oxytocin and dopamine not only help in establishing the bond between the child and mother but also help her in coping with the loss of sleep. New mothers lose on an average 700 hours of sleep in the first year of birth.

Bonding with the child – Growth of Love Circuit

The tender nurturing response of the oxytocin circuit is reinforced by the feeling of pleasure by bursts of dopamine. The reward circuitry is now working full throttle. This is the same circuitry that set off in a woman’s brain by love and orgasm. No wonder a new mother does not feel the need for sex!

These bonding circuits get reinforced daily with the trials and tribulations of taking care of a newborn. A mother who breastfeeds her infants has an extra stimulation of some of the most pleasurable aspect of Mommy’s brain.

The long-term impact on the brain

It is known for long that fetal cells may pass on to the tissues and organs of a mother. However, no study has been carried out to see the effect of these cells on mother’s brain. Recently a study has found those mothers who have more fetal cells in their brains are less likely to suffer from Alzheimer’s disease. Perhaps the fetal cells act as stem cells to replace mother’s old and diseased cells.

Nature ensures that the mother’s brain remains in the mom mode throughout her life. Even after resuming her menstrual cycle her hormone levels will remain lower than her pre-pregnancy levels. This bio tagging on the body also helps to lower risk of some types of cancer. In a nutshell, the changes mother’s brain undergoes is to keep the mother eternally engaged with her child.