U. S. Sen. Hillary Rodham Clinton, D-NY, and, former President Bill Clinton, blow out the candles on a cake at Hillary Rodham Clinton's 59th birthday party at Tavern on the Green in New York, Thursday, Oct. 26, 2006.
The unborn baby spends around 38 weeks in the uterus, but the average length of pregnancy, or gestation, is counted at 40 weeks. Pregnancy is counted from the first day of the womanâs last period, not the date of conception which generally occurs two weeks later.
In other words, a premature birth is one that occurs before the start of the 37th week of pregnancy. Normally, a pregnancy usually lasts about 40 weeks. Premature birth gives the baby less time to develop in the womb. Premature babies, especially those born earliest, often have complicated medical problems. Depending on how early a baby is born, he or she may be: Late preterm, born between 34 and 36 weeks of pregnancy.