Preterm birth is a serious problem. Complications from prematurity are the most common reason that babies die after birth, accounting for 70 percent of neonatal deaths. Half of the time, preterm birth occurs when a mother enters labor early or the amniotic membrane ruptures prematurely, and the doctor is unable to stop the early labor. The rest of the time, birth occurs due another reason, such as when the doctor feels that a health problem in the mother or baby necessitates delivery.
Preterm birth is defined by delivery occurring before 37 weeks gestation (the due date is set at 40 weeks), and the incidence is increasing in the U.S., where currently 12 percent of babies are born prematurely. Neonatal Intensive Care Units (NICU) may be able to save babies when they are born as early as 22 weeks gestation; although many of these extremely early babies have significant health and developmental problems.
Doctors lack the ability to accurately predict which women are at risk for preterm birth. The most significant risk factor is having a previous baby who was born early. A woman who has given birth early has double the risk of having an early delivery the next time she is pregnant. A recent test that helps doctors predict whether a woman may deliver early involves measuring the length of a her cervix by sonogram. A cervical length less than 2.5 cm prior to 24 weeks gestation usually requires additional treatment.
Other historical factors that may increase a woman’s risk of early delivery include prior cervical surgery (such as LEEP or conization) and uterine instrumentation (such as dilation and curettage for elective or spontaneous abortion). Factors in the current pregnancy that may increase risk include vaginal bleeding, urinary tract infections, genital tract infections, periodontal disease, and not surprisingly, having twins or a higher order gestation. A woman can decrease her risk of preterm delivery by avoiding smoking, substance abuse, and having her babies too close together (delivering another within 18 months).
What can a woman who has experienced an early delivery do to avoid this happening again? Prevention strategies depend on the reason for the early delivery. If a woman delivered due to cervical incompetence (when the cervix dilates early without contractions), her obstetrician can place a stitch after the first trimester in the next pregnancy to hold the cervix closed longer. If the delivery was recommended by her doctor due to severe hypertension, diabetes or other medical disorders, or because the doctor had concerns for the baby’s well-being because of these illnesses, she should work hard to make sure these problems are well controlled prior to becoming pregnant again. This may involve weight loss and working closely with an internal medicine doctor or endocrinologist to make sure she is on appropriate medications that are safe in pregnancy.
Are there medications that are effective in preventing preterm labor? While many medications and strategies have been used to try to prevent or stop preterm labor, most have not been proven effective in clinical trials. These unproven interventions include bed rest, hydration, home uterine activity monitoring, antibiotics, and medications such as indomethacin, nifedipine, and terbutaline. The most successful prevention strategy seems to be weekly progesterone injections starting at about 16 weeks gestation. Sometimes vaginal progesterone is given if the cervix is starting to shorten. Magnesium sulfate is usually given if a woman presents with preterm labor to the hospital, as this will often slow the labor long enough to give steroid shots which will enhance the baby’s lung maturity, and protect his or her brain from complications of prematurity. The best treatment is prevention, and thus a woman with a prior premature delivery will often be followed up with by a high risk specialist, or by her own obstetrician with frequent ultrasounds measuring the cervical length.
If you have had a baby prematurely, it is important to realize how much doctors do not understand about this devastating situation. What we do know is that it is highly unlikely that you did or didn’t do something right that allowed this to occur. So, take a deep breath, and forgive yourself. Having a premature baby does not mean that you have done something wrong to cause the early delivery. It is important now to educate yourself and move forward, and continue to care for your baby in the best way possible. And congratulations… becoming a mother is one of the most fulfilling ways you can live your life. Enjoy the blessing of your baby.
By Ingrid Skop, M.D.