In terms of its impact on infant health, preterm delivery (PTD) is the most significant complication affecting pregnancy. By definition, preterm refers to a gestational age of 37 weeks or less.

A woman’s due date is 40 weeks from the first day of her last menstrual period. PTD may be medically indicated because of a maternal problem (e.g. high blood pressure) or a fetal problem. This situation is called indicated preterm delivery (IPTD) and is usually unavoidable. PTD that follows spontaneous onset of preterm labor is referred to as spontaneous PTD (SPTD). This needs to be medically evaluated and treated because of the high risk to the infant associated with SPTD. As spontaneous preterm labor occurs at progressively earlier gestational ages, the risk to the infant, if delivered, increases steadily. The infant may be born with various health problems, including breathing difficulty (respiratory distress syndrome), feeding problems, visual problems, or kidney or intestinal problems.

Causes

Preterm labor is more common in women who have uterine problems such as fibroids, uterine over distension (due to twins, triplets, or excessive amniotic fluid) or cervical weakness (incompetence). Other risk factors for spontaneous preterm labor include previous SPTD, smoking, multiple gestations, drug use and rupture of the bag of waters.

Signs and Symptoms

Signs or symptoms of spontaneous preterm labor include uterine contractions/cramps, backache, pelvic pressure, vaginal bleeding, and increased vaginal discharge. More recent indicators or markers of an increased risk for preterm labor include shortened cervical length measured by vaginal ultrasound examination and a laboratory test of cervical-vaginal secretions for a substance called fetal fibronectin (FFN).

Treatment

Treatment for preterm labor includes immediate medical evaluation, monitoring for uterine contractions, testing for the presence of infection and possibly hospitalization, medications to suppress contractions, antibiotics, and steroid medications (betamethazone) to accelerate fetal lung maturity. This patient evaluation and treatment approach does not always prevent SPTD, but it has been shown to significantly reduce the risk associated with SPTD.

Women with preterm labor who are at risk for SPTD should be cared for in a hospital equipped to take care of their baby if the preterm labor cannot be stopped. If a woman is initially seen in a primary- or secondary-level hospital for evaluation of preterm labor, she may need to be transferred to a tertiary-level hospital, such as Sharp Mary Birch Hospital for Women. This type of a transfer (maternal-fetal transport) allows the woman and her fetus to be cared for in a setting that is best able to manage her labor, as well as her infant, if she delivers preterm.

With appropriate evaluation and treatment for preterm labor, good outcomes can be expected for mom and her baby.