The female body has amazing powers of recuperation. Within minutes of the birth, the uterus (womb) changes from a smooth-sided bag with a capacity to hold four-and-a-half litres of water to a grapefruit-sized pouch of muscle. Within six weeks, the uterus will have reduced in weight from 1000g, close to its pre-pregnant weight of 50g. The soft lining breaks down and is washed away in the lochia (the vaginal loss that lasts for a few weeks after giving birth). Heart, lungs and circulation, relieved of the burden of pregnancy, return quietly to normal.
The vagina will also gradually regain its former tone and the pelvic floor will return to its usual position. Tears to the neck of the womb, vagina and perineum usually heal quickly.
Levels of the hormone progesterone fall rapidly after childbirth. As a result, heartburn is swiftly relieved and constipation and varicose veins improve, although haemorrhoids (piles) generally take longer to resolve.
It also takes time for the joints of the pelvis and spine, softened by the hormones released during pregnancy, to return to normal. Back discomfort may persist for several months following delivery, so take care with lifting and carrying. The abdominal muscles, stretched to twice their normal length during pregnancy, regain their tone within a couple of months.
Getting back to your pre-pregnancy weight takes time.
The most rapid weight loss occurs in the first few days after delivery as the extra two to eight litres of water carried during late pregnancy are passed out as urine. After this, weight loss slows down, although if you breastfeed beyond six months - as nature intends - most mothers find that their weight naturally decreases.