DefinitionThe number of live births under 37 weeks gestation divided by the total number of live births over the same time period.
NumeratorNumber of live born infants born less than 37 weeks gestation.
DenominatorTotal number of live births.
Data Interpretation IssuesReporting of Preterm Birth (PTB) has been complicated by a change in how gestational age (GA) is calculated. PTB is defined as a birth less than 37 weeks gestation. Historically, GA was calculated by the mother's last menstrual period (LMP) and PTB rates were reported this way. Since the 2003 revision of the birth certificate, GA is more accurately calculated by obstetric estimate (OE). Now, almost all PTB rates are done with the OE. However, in order to compare PTB trends, sometimes LMP rates are still used so previous years of data can be compared.
Why Is This Important?Preterm birth, birth before 37 weeks gestation, is the leading cause of perinatal death in otherwise normal newborns and is a leading cause of long-term neurological disabilities in children. Infants born before 32 weeks gestation bear the biggest burden representing more than 50 percent of infant deaths. Babies born preterm also have increased risks for long term morbidities and often require intensive care after birth. Health care costs and length of hospital stay are higher for premature infants. For a preterm infant without complications, average hospital stays are three times longer than a term infant, and for a preterm infant with complications, average hospital stays are over seven times longer than a term infant. Utah inpatient hospital discharge data (2014) indicate that average hospital charges for a premature infant was $73,796 (DRG 386, 387, 388) compared to $2,922 for a normal newborn infant (DRG 391). Utah inpatient hospital discharge data (2014) indicate that average length of stay for a premature infant was 16.8 days (DRG 386, 387, 388) compared to 1.9 days for a normal newborn infant (DRG 391).
Healthy People Objective MICH-9.1:Reduce total preterm births
U.S. Target: 11.4 percent
State Target: 8.9 percent
How Are We Doing?Utah's preterm birth percentage increased from 8.8% in 1990 to 10.1% in 2005 and had been declining until 2015 where Utah's preterm birth rate increased from 9.1% in 2014 to 9.3% in 2015. This increase followed national increasing trends and was the first increase seen in six years. Utah's rate is still below the Healthy People 2020 Objective of 11.4%.
How Do We Compare With the U.S.?Nationally, the percentage of preterm births has been declining since 2007, reaching a low of 9.57% in 2014 with a slight increase to 9.62% in 2015 (preliminary). In 2013, the U.S. began reporting preterm birth rates based on obstetric estimates rather than based on last menstrual period (LMP) making it difficult to compare Utah to the U.S. farther back than 2013. The obstetric estimate has been shown to more accurately reflect the true gestational age of the infant than LMP.
What Is Being Done?Approximately half of preterm births in Utah are due to complications of the pregnancy (multiple births, placental problems, fetal distress, infections) or maternal health factors such as high blood pressure or uterine malformations. The remaining preterm births have unexplained causes. In an effort to reduce the preterm birth rate, emphasis is being placed on maternal preconception health to help women achieve optimal health prior to pregnancy. Some ways women can achieve optimal health would be to stop use of tobacco and alcohol, get chronic diseases such as diabetes and high blood pressure under control, and obtain an optimal pre-pregnancy weight. Early and continuous prenatal care is encouraged to detect problems that may arise during pregnancy. Women should be educated regarding the danger signs of pregnancy and the importance of recognition and treatment for these symptoms. Standards for assisted reproductive technology should be followed to reduce the frequency of twins or higher order multiple pregnancies. Pregnant women should also be referred for appropriate services such as WIC and psychosocial counseling.
Studies have demonstrated a substantial reduction in the rate of recurrent preterm birth in women receiving progesterone supplementation. Pregnant women who have had a previous spontaneous preterm birth, particularly in the immediately preceding pregnancy, should be offered progesterone supplement beginning at 16-20 weeks gestation. Women pregnant with twins or triplets may not benefit from this medication. It is likely that the ability to more precisely define who is, and is not a candidate for this treatment will be improved in the next few years. In addition, the optimum dosage(s) and method(s) of administration remain uncertain.
The maternal intervention group of the Utah Women and Newborns Quality Collaborative (UWNQC) ([http://uwnqc.org/]) has identified optimization of 17 alpha hydroxyprogesteronecaproate (17P) use to prevent recurrent spontaneous preterm birth (SPTB) in women with a previous history of SPTB as the primary focus of their efforts. This group has developed a series of videos on preterm birth prevention and is working to educate providers on the use of 17P. Efforts are also underway to educate families who have delivered prematurely on what they can do to prevent preterm birth from happening in future pregnancies. In addition, the maternal intervention group has also begun projects relating to access to immediate postpartum long-acting reversible contraception.