The normal length for a pregnancy is between 37 and 42 weeks. If a baby is born before the 37th week, or 259 days of gestation, the baby will be considered a premature baby. Most babies born after about 32 weeks will usually be fine, but those born before 32 weeks often experience complications and will need some form of special care.
Around 1 in 9 babies are born prematurely in the UK and require special care.
The longer your baby stays in the womb, the less likely your baby will have serious health problems. For this reason, unless it is not safe for the mother or baby to continue with the pregnancy, doctors will try to ensure you don't have a premature birth before 37 weeks.
How will my premature baby look when he or she is born?
Depending on how premature the baby is, his or her appearance may differ from that of a full-term baby.
At 24-28 weeks: The baby's head will look large and have soft skull bones, with a small face, pointed chin and eyes fused closed; the baby will be very thin and the fragile skin will be red and covered with lanugo, a downy hair. Typical weight: 1-3.5lb (450-1600g). Typical length: 10-13in (25-33cm).
At 29-34 weeks: While the baby will still be very thin, the skin will be slightly translucent with lanugo; the baby may move vigorously and be capable of grasping your finger and may be able to suck or lick. From 32 weeks onwards most premature babies have a mature suck. Girls may develop tiny nipples. Typical weight: 2-5.5lb (1-2.5kg). Typical length: 12-14in (30-35cm).
At 35-37 weeks: The baby will look similar to a full-term baby but will be thin and with some hair; the baby will still need help staying warm and with feeding and breathing. Typical weight: 3.5-7lb (1.6-3.4kg). Typical length: 15-18in (38-45cm).
What complications may occur if my baby is born after 32 weeks but before 37 weeks?
Babies that are born before 37 weeks but who stay in the womb for at least 32 weeks are normally expected to do well. Babies born between 34 and 36 weeks are considered 'near-term' - there is a risk of problems with blood pressure and blood sugar levels as well as infection, and the baby may not be able to breast or bottle-feed. Babies born between 32 and 33 weeks are considered 'moderately preterm'. They will need special care for mild breathing and blood sugar problems and a risk of hypothermia, low blood pressure and infection. Although these may need to stay in the hospital longer than average and may be smaller than normal, they are expected to eventually catch up on the developmental stages with other babies that are born at full term between 37 to 42 weeks.