Premature delivery or preterm delivery is the one that takes place before the 37th week of pregnancy. It presents gynaecological complications and complications for the newborn baby, since it may lead to many health problems in the child, or even to his death. It’s calculated that approximately 5% to 10% of the deliveries are premature.
It must be taken into account the fact that pregnancy usually lasts 40 weeks and they begin to count from the woman’s last period.
Even though in some cases the suspicion of a premature deliver may arise, the cause of the premature delivery is not known yet. There are several factors that must occur in order for delivery to take place, but four main causes have been identified over the years: uterine overdistension, uterine infection or inflammation, decidual bleeding and precocious fetal endocrine activation.
Although a woman may have a normal pregnancy and take all the necessary precautions, it’s possible that preterm delivery takes place. There are several studies that show that black women have more possibilities to suffer from premature delivery than white women, however the cause of the differences between races is still unknown, even though research is being carried out.
Even though the cause is usually unknown, there are several factors that play a role on premature delivery.
In order to analyse the risk factors, they tend to be divided depending on their nature.
On the one hand, we can talk about the habits of the mother during pregnancy: unhealthy behaviours while pregnant, such as the consumption of alcohol and drugs or smoking are risk factors. If the pregnant woman suffers from obesity or has put on a lot of weight during pregnancy, the likelihood of preterm delivery increases.
Some conditions during gestation may increase the probability of premature delivery, for instance:
- Multiple pregnancy
- Polyhydramnios: excessive amount of amniotic fluid.
- Infection in the mother, which not necessarily is a uterine infection, any kind of infection may lead to preterm delivery.
- High blood pressure in the woman.
- Pre-labour rupture of membranes.
Uterine alterations, such as a short cervix, uterine malformations, or a bad functioning of the placenta, such as placenta praevia or placental abruption, can cause preterm delivery.
When there are evident signs of preterm delivery, what must be done is delaying labour as much as possible and preparing for the baby’s birth, which is usually done simultaneously.
If it’s achievable, birth tends to be delayed as much as possible, so that the foetus can carry on developing and growing. In these situations, absolute rest is advised for women. Lying in bed decreases the pressure on the cervix and avoiding the weight of pregnancy, the likelihood of contractions is reduced. In the case that the woman is in hospital, intravenous serum is applied, so that the woman is as hydrated as possible and medication against the apparition of contractions may be provided.
Despite these strategies, many preterm deliveries are unavoidable. One of the most common complications in preterm babies is the fact that their lungs are not still mature and don’t produce the lung surfactant substance, provoking severe respiratory complications. Glucocorticosteroids are supplied to pregnant women to stimulate the maturation and growth of foetal lungs, but in order for them to be provided, pregnancy must have reached week 24.
Depending on the moment when the premature delivery has taken place, the newborn baby will suffer from more or less complications. Before week 28 it’s considered as extremely premature labour, between week 28 and 31 they are considered severely premature infants, and moderately premature is between week 32 and 33. The best prognosis is for those babies born between weeks 34 and 36, considered slightly premature.