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) trends has been complicated by a change in how gestational age (GA) is reported by the National Center for Health Statistics. 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 also reported by obstetric estimate (OE), which is considered more accurate. Beginning in 2010, national rates are reported using OE and are not consistent with rates reported before 2010. Utah rates have been reported using OE since 1996.
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 (2019) indicate that average hospital charges for a premature infant were $90,734 (DRG 790, 791, 792) compared to $4,127 for a term newborn infant (DRG 795). Utah inpatient hospital discharge data (2019) indicate that the average length of stay for a premature infant was 16 days (DRG 790, 791, 792) compared to 2 days for a term newborn infant (DRG 795).
Healthy People Objective MICH-9.1:Reduce total preterm births
U.S. Target: 9.4 percent
State Target: 8.9 percent
Other ObjectivesThe Healthy People 2030 has an objective of reducing Preterm Births- MICH-07 with a baseline of 10% (2018) and a goal of 9.4%.
How Are We Doing?The Utah preterm birth rate increased from 8.8% in 1990 to a high of 10.1% in 2005. The rate has remained under 10% from 2006 to present. The Utah preterm birth rate decreased by 4.6% in 2020 going from 9.72% in 2019 to 9.27% in 2020.
How Do We Compare With the U.S.?The U.S. preterm birth rate declined to 10.09% in 2020 from 10.23% in 2019, the first decline in this rate since 2014. The percentage of infants born preterm (births at less than 37 completed weeks of gestation) fell 8% from 2007 (the most recent year for which national data are available based on the obstetric estimate of gestation to 2014, then rose 7% from 2014 (9.57%) to 2019. Available from:
The Utah 2020 rate of 9.27% is below the national rate and below the Healthy People 2030 goal of 9.4%.
In 2010, the U.S. began reporting preterm birth rates based on obstetric estimates rather than based on the last menstrual period (LMP) making it difficult to compare Utah to the U.S. farther back than 2010. 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 the 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 include stopping the use of tobacco and alcohol, controlling chronic diseases such as diabetes and high blood pressure, and obtaining an optimal pre-pregnancy weight. Early and continuous prenatal care is encouraged to detect problems that may arise during pregnancy. Education should be provided on the urgent maternal warning signs (https://www.cdc.gov/hearher/maternal-warning-signs/index.html) 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 Women, Infant, and Children (WIC) and psychosocial counseling.
The maternal committee of the Utah Women and Newborns Quality Collaborative (UWNQC) worked to prevent recurrent spontaneous preterm birth (SPTB) in women with a previous history of SPTB. This team developed a series of videos on preterm birth prevention. The committee has produced materials to help educate families who have delivered prematurely on what they can do to reduce the chances of preterm birth from happening in future pregnancies. In addition, the maternal committee has worked on access to immediate postpartum long-acting reversible contraception as well as other family planning access.