The March for Babies: Infant Prematurity

Barbara Head, MD, and JT Christmas, MD
Commonwealth Perinatal Services

Over 4 million babies are born in the United States each year and unfortunately, 1 in 9 is delivered prematurely, prior to 37 weeks of pregnancy. Prematurity can be the result of either spontaneous preterm birth from spontaneous preterm labor or preterm premature rupture of the membranes. It can also be indicated because of serious maternal or fetal complications, such as fetal growth restriction, hypertension, uncontrolled diabetes, or preeclampsia. Regardless of the reason for delivery, prematurity has significant impact both in terms of potential life-long medical complications, including infant mortality, as well as profound impact on families and society.  Preterm birth is the leading cause of neurologic handicaps of childhood. Efforts have been underway for years to identify pregnancies at risk for preterm birth so that measures can be taken to avoid premature delivery.

Prematurity is a complex problem with no clear single pathway.  We are aware of many risk factors, including, but not limited to, enlargement of the uterus from multiple (twin, triplet, or more) pregnancy, conditions which cause increased amniotic fluid volume, a previous premature delivery, previous cervical surgery, uterine abnormalities and tobacco use. However, many pregnancies with these risk factors do not deliver prematurely; and many patients who deliver prematurely do not have any of these risk factors. In addition, ethnicity appears to play a role in preterm birth with an increased risk of preterm delivery in African American women regardless of their other risk factors.  Researchers have identified genetic differences in African American women which may contribute to this increased rate of preterm delivery.

Women with a history of prior preterm delivery are at particularly high risk for recurrence. Research studies have demonstrated that therapy with a hormone called progesterone can significantly decrease the risk of recurrent preterm birth in this group.  Beginning in the middle of the second trimester, patients with prior preterm deliveries may be offered progesterone to be continued through the term of the pregnancy. Additional research has shown that in women who have already delivered prematurely, as the cervix of the uterus thins out or shortens, the risk of premature delivery increases. In such pregnancies felt to be at the highest risk of preterm birth, glucocorticoids, a type of steroid, may be administered to enhance the maturity of the fetal lungs.  Studies both in the United States and Europe have shown that administering magnesium sulfate to women at risk of imminent preterm birth can help to decrease the risk of infant death or moderate to severe cerebral palsy.

Interestingly, multicenter research initially performed in and published by the Hospital Corporation of America revealed that a large number of babies admitted to the neonatal intensive care units (NICUs) were because of non-medically indicated deliveries prior to 39 weeks gestation. With the efforts of the March of Dimes, a nationwide initiative is under way to reduce the practice of elective delivery prior to 39 weeks, resulting in a significant decrease in NICU admission.

Unfortunately, the majority of babies delivered prematurely are not delivered to women at increased risk. Ongoing efforts in Maternal-Fetal Medicine are directed at appropriately identifying those pregnancies well before they present in active preterm labor. Ultrasound evaluation of cervical length in the mid-trimester has promise to identify such women. In women with a shortened cervix at mid-trimester, ultrasound therapy with vaginal progesterone has been shown in several studies to decrease preterm birth risk. Decreasing the risk of cervical surgery by immunizing women against human papilloma virus (HPV) and avoiding abnormal pap smears may significantly impact the preterm delivery rate in years to come. Public education regarding the ill effects of tobacco use in pregnancy, the impact of obesity on pregnancy outcomes, and the signs and symptoms of preterm birth may have a further role in decreasing infant prematurity rates.

The March of Dimes, now devoted to helping mothers have full term births and healthy babies, was originally established by Franklin D. Roosevelt to fight polio. Originally called the National Foundation for Infantile Paralysis, the organization’s original mission was accomplished when polio vaccines were developed by Jonas Salk, MD, and Albert Sabin, MD. After accomplishing this revolutionary mission, the March of Dimes shifted its focus to the prevention of birth defects and infant mortality. Since 2003, the Prematurity Campaign has been the hallmark of the March of Dimes, having raised awareness of prematurity locally, nationally, and internationally. Thanks to the efforts of the March of Dimes, the work of numerous researchers, and obstetric care providers in every community, the rate of prematurity has finally begun to decrease nationwide to a recently reported rate of 11.5%. All states have signed a pledge to continue work toward this goal by decreasing the number of uninsured women, decreasing the rate of smoking in pregnancy, increasing the use of progesterone in at-risk women, and decreasing unnecessary inductions and cesarean deliveries prior to 39 weeks.

For further inquiries about infant prematurity or high-risk pregnancy, contact JT Christmas, MD, or Barbara Head, MD, at Commonwealth Perinatal Services at 804.289.4972.