antagonists are given to newborn mice, it completely inhibits suckling and growth in the pups, and they die within days of its administration. Formula-fed babies may get fatter for the same reason pot smokers have smaller waistlines than nonpartakers. Even though stoners might ingest more calories, it does not result in a higher body mass index. Cannabinoids in breast milk likewise help to regulate the baby’s metabolism.
One downside of nursing? Because of our increasingly contaminated environment, our breast milk now has appreciable levels of pollutants like flame retardants and polybrominated diethyl ethers (PBDEs). These can interfere with thyroid function and cause masculinizing features in our girls and feminizing ones in our boys. I still believe that the upsides, particularly the substances found only in breast milk, outweigh this horrific fact. But one more upside: you burn about thirty calories for every ounce of milk you produce. I ate like crazy during those early motherhood years and managed to lose the “baby fat” fairly quickly. I’d be pumping breast milk into a bottle, counting the calories as the ounces accumulated. Ten ounces were as good as a three-mile run!
Bonding
Attachment is crucial for our mates and our children, hence the postcoitus bump in oxytocin as well as those sustained high levels when nursing. The bonding hormone oxytocin is the glue that keeps mother and child together, mother and father together, and even father and baby together. Babies have oxytocin just like moms. Cuddling and nurturing produce elevated levels of oxytocin, calming their stress response. And it turns out that dads have oxy too. During the early phases of parenthood, cohabiting parents share elevated oxytocin levels, which are often interrelated. Although some men may be more likely to cheat when their mates are pregnant or are new mothers, it could be that if you allow your partner more time with his baby, his bond will be stronger not just with his child but with you as well. Vasopressin is the biggest factor in paternal behavior, helping a dad to protect his child and bond with its mother. Men have prolactin as well, which elevates as they hear their baby’s cry, just as a woman’s prolactin levels do.
Like other animals, and especially primates, we thrive on attachment and perish without it. Monkeys reared without physical contact with their mothers become violent and socially impaired as adults, their brain chemicals imbalanced after only a few days of separation from them. In laboratory animals, if a mother doesn’t respond to her pup’s distress call, the pup will die even if it’s fed. The type of attachment we receive early on will affect our emotional functioning thereafter. Maternal care in infancy affects anxiety regulation in the brain of the offspring. Any disruption of attachment in infancy can lead to exaggerated stress reactions down the road in adulthood. Unmet emotional needs will trigger a stress response not just in childhood but potentially throughout adulthood as well. This is important to remember not just in mothering but also in being an attentive wife or partner. Disrupting the attachment bond causes all sorts of heartbreak and behavioral upheaval whenever it happens.
Attunement to our children’s emotional states and needs helps us to fine-tune our relationship with them. When we give our children loving attention, we not only influence their brain circuitry but also affect their future relationships. When we’re distracted, stressed out, or unavailable, our children suffer for it. Down the line, they may choose partners who treat them similarly, reenacting those early separations.
A tuned-in parent can help produce a healthy child. What our kids need most is our genuine presence. For children today, it is confusing and traumatizing to have a parent’s face on a computer or smartphone screen most of the day. We may be physically present, but we are not emotionally available. It’s hard for toddlers to wrap their heads around that paradox, called proximate separation. I’m here, but I’m not really here for you. We need to engage deeply and authentically with our kids, provide an anchoring gaze, mirror their communications, and validate and empathize with their emotions and experiences. This takes attention and focus, which can’t be divided between their faces and our glowing devices.
Postpartum Depression
The biggest disrupter of early infant-mother bonding is severe depression, which may occur after delivery. I have a colleague whose mother committed suicide when he was four months old, convinced he’d be better off without her. It has colored his entire narrative; that attachment disruption was forever wired into his stress response and temperament.
Postpartum is a vulnerable time for women both pharmacologically and psychologically, and it’s common to be down. As many as 50 to 80 percent of women report a milder form of depression, sometimes called the baby blues, which may last a week or two. But roughly 10 to 15 percent have a true postpartum depression, disrupting functioning in a number of areas for at least two weeks: energy, appetite, sleep, and libido. More rare is a syndrome called postpartum psychosis, occurring in one out of a thousand deliveries, often accompanied by dangerous thoughts. I’ve interviewed new mothers in emergency rooms at Mount Sinai and Bellevue with a similar delusion, that their baby was the root of all evil, and if they could smother the baby, they’d save the world. Scary stuff, and those women had to be hospitalized and treated with antidepressants and short-term antipsychotics and were separated from their infants temporarily. This is why I do recommend that a psychiatrist get involved to assess whether you need treatment if your mood is down more days than not after you’ve delivered.
Prolactin, the hormone responsible for milk production, reaches its highest levels when we’re nursing. Good news for a hungry baby. Not always great for the mom. Prolactin can make us sleepy and depressed. Sometimes the postpartum blues are associated with higher prolactin levels. Other times, the culprit is a quick drop-off of estrogen that occurs after delivery. Although there are massive changes in hormones that occur during pregnancy, they tend to occur gradually. Many of these changes quickly return to baseline right after delivery. Because of this, you can go from being blissed out to being an anxious mess in a matter of days. If you think about it, you can see why it would be biologically advantageous to be a bit jumpy and hypervigilant after your baby is born. Nature sets you up to be a hovering mother so you can keep your baby safe and attend to its every need. These hormonal drop-offs can be an uncomfortable and rocky time for many new mothers. Add being sleep-deprived and in constant need of a shower, and it’s understandable why you’d be irritable and weepy.
The peak time for postpartum depression isn’t right after the baby is born, but rather at ten weeks. Depending on when you wean your baby off breast milk, you may end up with a delayed postpartum depression as the oxytocin wanes. Breast-feeding reliably reduces the risk of postpartum depression, but in women who wanted to nurse but couldn’t, the rate of postpartum depression is actually higher. So these women need more
