Pregnancy and childbirth take an awful lot out of women. Their organs get shifted out of place, they may suffer from pregnancy- and breastfeeding-related osteoporosis, they could be (and probably are) permanently scarred from surgical cuts (either episiotomies or C-sections) made during delivery, and a good number endure gestational diabetes and a host of other health problems they never dreamt they’d have before they got pregnant. Not to mention the exhausting process of taking care of the newborn after they’ve finally evicted the baby from their womb, the lack of sleep, and the danger of post-partum blues.
The only “renewal” I can think of is a teensy bit sinister: the cells of the foetus often make it past all the barriers that are supposed to keep the developing baby separate from the mother’s immune system, and these cells are known to invade the mother’s brain, her bloodstream, her organs, her breast cells, her skin… potentially any part of her body, really. And they lodge inside the mother for the rest of her life, long after the baby is born and the kid grows up. Some studies have put a positive spin on this foetal-cell invasion by suggesting that the cells could help the mother heal from various illnesses and injuries. Others have suggested that these foetal cells behave more like cancerous cells and may raise the mother’s risk of cancer. Either way, they’re a kind of “renewal”, aren’t they? Whether they heal, or whether they “renew” cells the way cancer cells are so good at growing on and on, foetal cells that have permanently invaded the mother’s body are one way I can think of for childbirth to be a factor in a woman’s body renewing itself.
Here’s a link to one of the reports that takes the more positive perspective:
Fetal Cells May Protect Mom From Disease Long After The Baby's Born