“You go home with a 6 months pregnant body and your short term memory temporarily gone.”
Motherhood alters a woman’s brain – structurally & functionally. Our genetic code has triggers for basic mothering that are primed by the hormones of pregnancy, activated by labor, and reinforced by close, physical contact with our child. Physical cues from the infant stimulate new neurochemical pathways in the brain, chemical imprinting, huge amounts of oxytocin – all of which result in a motivated, highly attentive, and aggressively protective brain that forces the new mother to alter her responses and priorities in life. She is relating to this person in a way that she has never related to anyone else in her life.
The mommy-brain transformation gets underway at conception and can take over even the most career-oriented woman’s circuits, changing the way she thinks, feels, and what she finds important.
First comes the mellow, sedated brain. She needs to rest, eat & drink more. Her brain reacts to certain smells & foods (speculated to be certain instincts against harming the fetus). By the 4th month, hunger increases, but the hormones still have a tranquilizing effect, a protection against stress. She may feel vigilant about safety, nutrition, and her surroundings. In the last months of pregnancy, the mom-to-be brain may be forgetful, distracted, and preoccupied.
It is a biological reality that the brain is actually changing in size and structure. Some parts of her brain get larger, others smaller, and it will return to its normal state at about 6 months postpartum.
Near birth, her circuits switch to preoccupation with the baby and high alert. Huge cascades of hormones during labor will help forge new connections between neurons. In the days following birth, these neurons will impact hypervigilance, protectiveness, and imprinting, because the instincts are activated for monitoring and tracking baby.
Brain scans show that mother love looks like romantic love. Highly increased Oxytocin-activated regions of the brain result in passionate love for the child. Surges of dopamine, prolactin, and oxytocin switch off judgment and negative thinking – switch on pleasure circuits. Breastfeeding activates even more pleasure circuits. (In experiments, rats pressed the lever for getting their pups to suck over the lever for a squirt of cocaine).
After any initial breastfeeding pain or struggle, the experience becomes pleasurable, dreamlike, peaceful, relaxed. These are hardwired responses in the maternal brain. Being physically separated from new baby or later weaning of baby creates a neurochemical state mirroring drug “withdrawal” symptoms.
The downside of the warm, nurturing mommy brain is a lack of mental focus, “fuzzy brain.” Experienced as absentminded, memory loss, harder to concentrate, mental fog, some women may even find it difficult to hold a conversation!
The male brain changes as his mate’s pregnancy progresses. He has emotional, physical, and hormonal shifts in parallel to the pregnancy. Some of these changes may be from airborne chemicals – pheromones – from her skin and sweat glands. These hormones are priming him for paternal behavior.
Fathers have instincts too. Research during the last trimester shows that for men prolactin levels increased by over 20% and testosterone dropped 33 % during 3 weeks before the birth. By the time of birth, the men were also better at hearing and emotionally responding to crying babies than non-dads were. Testosterone & prolactin levels will begin to readjust when baby is around 6 weeks old, returning to pre-fatherhood levels by the time the baby is walking.
The making of the daddy brain requires not only hormones and paternal brain circuits but also physical touch. Hormone levels depend on how much on-hands care the dads give. Skin to skin contact with a baby promotes bonding – like the mom, his brain circuits respond as if falling in love. His brain has receptors for “fathering hormones”: prolactin, oxytocin, vasopressin, and hands-on fathering increases the number of connections in the male brain for paternal behavior. Moms’ brains may be on high alert from day one; dads’ brains can quickly catch up.
The baby is initially more bonded to mom from the intensely pleasurable sensations of breastfeeding, but around 3 months old, dad begins to play a starring role. There is less time sleeping and more time interacting.