Preterm/ premature labor is defined as onset of labor symptoms prior to 37 weeks of pregnancy. The symptoms may include regular uterine contractions, “show” or spontaneous leaking of amniotic fluid. There is an associated cervical dilatation on vaginal assessment.
Preterm birth understandably is a concern, as babies who are born too early may not be fully developed. This leads to serious health problems including cerebral palsy, that last a lifetime. They can also suffer blindness, deafness and learning disabilities, later in childhood or even in adulthood. The risk of health problems is greatest for babies born before 34 weeks of pregnancy.
Complications of prematurity
- Respiratory distress syndrome (immature lungs)
- Cerebral palsy
- Necrotizing enterocolitis
- Intraventricular/Brain hemorrhage
- Patent ductus arteriosus
- Retinopathy of prematurity, Deafness
- Hypothermia, low birth weight, jaundice
- Complications of hospitalization including infection/sepsis
Premature birth remains a leading cause of perinatal morbidity and mortality. Currently, there is no effective measure to prevent this pregnancy complication. However, some risk factors have been identified, which include the following:
- Previous history of preterm birth
- Having a short cervix
- Short interval between pregnancies
- Previous history of certain types of surgery on the uterus or cervix
- Pregnancy complications, such as multiple pregnancy and vaginal bleeding
- Lifestyle factors such as low pre-pregnancy weight, smoking during pregnancy, and substance abuse during pregnancy
In the presence of one or more of the risk factor, it is advisable to seek early consultation with your obstetrician even before pregnancy (pre-conception assessment). The doctor will attempt to identify factors that can be optimized including making sure you are in good health, discussion on antenatal care and delivery.
What if I have symptoms of premature labor?
You need to be attended by the obstetrician to confirm the diagnosis. It is difficult to predict which will go on to have preterm birth. Only about 10% of women with preterm labor will give birth within the next 7 days. For about 30% of women, preterm labor stops on its own. If preterm labor continues, some medications that are commonly prescribed to improve the baby’s outcome are tocolytics, steroid and magnesium sulfate.
Tocolytics are drugs used to delay delivery for a short time (up to 48 hours). They may allow time for corticosteroids or magnesium sulfate to act on the fetus and/or for transfer to a hospital with specialized care for preterm babies. Oral Nifedipine is the commonest tocolytic used in preterm labor.
The steroids are drugs that are used to mature the fetal’s lungs, brain, and digestive organs. It is most beneficial if given between 24 weeks to 34 weeks of pregnancy.
Magnesium sulfate is a medication that may be given if you are less than 32 weeks pregnant and are at risk of delivery within the next 24 hours. This medication may help reduce the risk of cerebral palsy that is associated with early preterm birth.
If the premature labor is imminent, your baby will be arriving earlier that it should be. Generally, the outcome is better if delivery is between 34-37 weeks, as most organs (especially the lungs) would have matured. For babies delivered between 28-34weeks, they are at risk of respiratory complications associated with lung immaturity. Most research had shown that tocolysis and steroid administration improve the fetal outcome. Meanwhile, the prognosis is guarded if the baby is born before 28 weeks.
Irrespective of the timing of premature labor, there is always an anticipation for the need to be care at a neonatal intensive care unit (NICU). The baby may need specialized care for ventilation and associated complications, low birth weight and hypothermia, amongst others.
Premature labor is not common but can be associated with significant newborn complications. When it is imminent, tocolysis and steroids, are commonly administered to enhance the prognosis. A tertiary level care is required in anticipation of the associated complications of prematurity.