What is premature labour (preterm labour) and premature birth?
A normal pregnancy lasts about 40 weeks, measured from the first day of the last period (38 weeks after fertilisation). Uterine contractions and dilation, which is the opening of the cervix, before the 37th week of pregnancy is called premature or preterm labour. Babies born before the 37th week of pregnancy are called premature babies.
In the UK, about 10% of all pregnancies result in premature birth. The more premature a child is when born, the greater the risk of problems. However, the longer the duration of pregnancy - that is, the less premature a baby is - the lesser the chance of problems and the greater the chance that a child will survive.
The problem with premature labour is that a baby will be born prematurely and his or her bodily organ systems will not be fully developed. In turn, this means a child may not be able to function and sustain life without medical support. Fortunately nowadays with the availability of neonatal intensive care units (NICU), where babies can be cared for whilst their organ systems mature, most babies born prematurely survive and do very well.
Depending on how premature a child is when they are born problems experienced by the baby may include:
Premature babies are at higher risk of long-term complications, which may include visual impairment or blindness, hearing impairment, cerebral palsy and chronic lung problems. The earlier the baby is born, the more likely that he or she will have these problems.
Who has premature labour?
About one in three premature babies are delivered for medical reasons, either for your safety or your baby’s. You should know that you are more likely to experience premature labour or premature birth if:
- You've had premature labour or delivered a premature infant in the past.
- You're carrying more than one baby (multiple pregnancy).
- Your mother used the medication diethylstilboestrol (DES) while she was pregnant with you.
- You have an abnormally shaped uterus or an abnormal cervix.
- You've had a cone biopsy of your cervix.
- You're younger than 17 or older than 35.
- You became pregnant while using an IUD, and the IUD was left in place during pregnancy.
- You were significantly underweight when you became pregnant.
- You smoke or use illegal drugs.
- You've had second-trimester miscarriages during previous pregnancies, or you've had three or more elective abortions.
- You have pre- eclampsia, kidney disease, heart disease, diabetes, an infection or other medical condition.
- You're not receiving antenatal care from a qualified healthcare provider.
- You have a cervical infection, such as group B streptococci, gonorrhoea, chlamydia, syphilis, trichomoniasis or gardnerella.
- Your job involves extremely strenuous, physical work.