Preterm birth is the single largest contributor to neonatal morbidity and mortality. Nearly 12 percent of all deliveries occur prior to 37 weeks.
Babies who are born preterm are at an increased risk for neurologic, respiratory and digestive complications. These risks are inversely correlated to the child’s gestational age at birth. The devastating effect of premature birth may follow a child through life.
Not all premature births are a result of preterm labor. Nearly half of preterm births occur due to a maternal or fetal condition that necessitates early delivery. Spontaneous preterm labor precedes almost half of preterm births. It is in the second group that efforts to reduce neonatal morbidity and mortality must focus on two questions:
▪ What can be done to reduce the rates of preterm birth?
▪ For infants destined to be born prior to term, what steps can be taken to reduce the affect of prematurity?
The two greatest predictors of preterm birth are prior preterm birth and multiple gestation. For women with a history of prior spontaneous preterm birth who are now carrying a single fetus, weekly progesterone injections starting between 16-24 weeks have been shown to be an effective way to decrease the chances of recurrent preterm birth.
Also, the use of ultrasound to measure the length of the cervix may help to predict increased risk for recurrent preterm birth. In a woman with a shortened cervix prior to 24 weeks, cervical cerclage (placement of stitches in the cervix to hold it closed) has been associated with a 30 percent reduction in birth at less than 35 weeks.
For a woman with multiple gestation, the average age of birth is inversely related to the number of fetuses carried. For this reason, reproductive endocrinologists who perform in vitro fertilization have taken great care to refine their techniques to reduce the likelihood of triplet gestation.
For those patients in preterm labor who will eventually deliver preterm, several interventions may improve neonatal outcome. Antibiotics given to the woman in preterm labor may reduce the frequency of neonatal infection (i.e. pneumonia, meningitis and sepsis).
Furthermore, parenteral steroids given to the mother in the hours preceding delivery have been shown to improve newborn lung function and decrease the rates of neurologic and digestive complications.
Finally, magnesium sulfate administered intravenously to the woman who is likely to deliver within 24 hours may reduce the likelihood of neurologic complications, including cerebral palsy.
Dr. Bradley Youkilis is an OB/GYN with Baptist Health Medical Group Women’s Care Lexington and practices at Baptist Health Lexington.