The 4th trimester concept
We measure pregnancy over nine months divided into thirds: the first trimester is a secret time, when an embryo develops into a foetus hidden away from the outside world; in the second trimester news of the pregnancy is shared and celebrated and preparations begin; in the third trimester the focus moves to the impending birth and plans made for labour and delivery. We celebrate the arrival of the newborn as though the journey has ended. But for the newborn, an even bigger transition must now be made.
“Birth no more constitutes the beginning of the life of the individual than it does the end of gestation. Birth represents a complex and highly important series of functional changes which serve to prepare the newborn for the passage across the bridge between gestation within the womb and gestation continued out of the womb.” (Montagu, 1986, 57)
Adjusting to life outside the womb is probably the biggest change we experience in a lifetime, yet little thought is given to how that transition is made. What is often referred to medically as the postnatal period, has been better described as The Fourth Trimester by Harvey Karp, renowned paediatrician and author of “The Happiest Baby on the Block”.
The Fourth Trimester, roughly the first twelve weeks, is also described as exterogestation: literally Gestation Outside of the Womb. Compared to many other mammals, humans are born in a very immature state. While some herd animals need to stand and walk within hours after birth, human infants can barely support their own head! It is even suggested, in comparison to other mammals, that humans would need another twelve to eighteen months in the womb to reach neonatal maturity! But I doubt any of us would be up for a 27-month long pregnancy, let alone the prospect of birthing a toddler. And therein lies the problem.
Karp suggests that humans have evolved to birth at least three months prematurely, as the typical newborn skull and typical maternal pelvis are basically incompatible beyond 42 weeks. Leaving us with babies who are mature enough to survive outside the womb by breathing on their own but not independently capable of any other aspect of survival.
Human society has long understood the special needs of newborns and their mothers in the early weeks after birth: the 40 days has traditionally been a period where new mothers are secluded and nurtured by the women of their community, while others take on her domestic and familial responsibilities. But modern western lives have gradually worn away these traditions for most mothers.
