November 17, 2021

Preterm Birth in the United States: Exploring Disparities, Implications, and Interventions

By Gabriella Watson, MS, Science Programs Coordinator. 

Setting the Stage: Prevalence of Preterm Birth Disparities in the United States
In the United States, around 390,000 infants are born prematurely (before 37 weeks of gestation) each year, accounting for 42% of all preterm births (PTB) across high-income countries. Although PTB rates in the United States declined from approximately 10.44% to 9.57% between 2007 and 2014, since 2018, it has risen to above 10%, giving the United States one of the highest PTB rates in the world.

The rate of PTB varies greatly by race and ethnicity, with increasing disparities for women of color, who are up to 50% more likely to give birth prematurely than white women. Black women experience the highest rates of preterm birth (14.4%), followed by Native American (11.6%), Hispanic (9.8%), White (9.1%), and Asian (8.5%) women. Black women are also five times more likely to experience a recurrent preterm birth than white women.

Despite the prevalence of preterm births and the history of disparities in preterm birth experienced by Black mothers and women of color, this maternal and infant health crisis has only recently received public recognition. Given the growing attention to maternal and infant health as a public health issue, calls for action related to the impact of structural racism and the health of mothers and babies, and congressional efforts aimed at improving maternal and infant health, there is an opportunity for increased research efforts to address the stark gaps in preterm birth rates.

The Role of PTB in Infant Health Outcomes
The Centers for Disease Control and Prevention (CDC) classifies PTB into two categories: early (before 34 weeks of gestation) or late (between 34 and 37 weeks of gestation). Infants born prematurely often have underdeveloped lungs, skin, and digestive and immune systems, and are therefore at increased risk for neonatal complications, such as low birth weight, jaundice, breathing and feeding difficulties, infection, and challenges with digestion and vision. The more premature an infant is born, the greater the risk for adverse short- and long-term health complications.

On average, premature infants are hospitalized up to 13 days, have higher rates of re-hospitalization, and require complex care once discharged from the hospital. This often results in high out-of-pocket costs, increased debt, and financial worry amongst families. In the first year of life, health care costs can amount to 10 times more than for full-term infants, averaging over $32,000.

Beyond the specific care and out-of-pocket costs that are needed in a preterm infant’s early years, individuals born prematurely often require specialized care, including counseling, physical and occupational therapy, and special education accommodations into childhood and adulthood. Although adults born preterm are a steadily increasing population, the long-term impacts of PTB into adulthood, including their specific health needs, is still largely unknown and represent an important research opportunity within the preterm birth space.

Elevating Maternal Health Through PTB Conversations
Maternal, infant, and child health are interconnected. Yet, too often, conversations surrounding PTB do not consider the mother’s health and well-being despite the higher rates of post-traumatic stress, postpartum depression, and anxiety experienced by women who give birth prematurely. Even years after a PTB, mothers report moderate to severe anxiety, higher rates of depression, poorer family functioning, and higher levels of parenting stress.

Despite efforts to collect better, standardized data on maternal health outcomes, data can be unreliable and incomplete. Critical data on maternal race, ethnicity, income, and health insurance coverage are not routinely collected across all states, making it difficult for researchers to identify the potential risk factors and causes of preterm birth, which could ultimately help address the root causes of maternal health outcomes and the disparities experienced by women of color.

Understanding and Approaching PTB
PTB is a complex health crisis that is influenced by intersecting sociocultural, environmental, clinical, and genetic risk factors. Women who have had a premature birth in the past, who are pregnant with multiples (twins, triplets, etc.), or who have a history of uterine or cervical conditions (e.g., congenital defects, uterine fibroids or scars, cervical insufficiency) have increased risk of delivering prematurely. Emerging research also suggests that women with a first-degree relative (mother, sister, aunt) or women who themselves were born prematurely are also at increased risk for having a PTB.

These factors, while helpful for conveying risk, do not explain the cause of PTB. Spontaneous labor, premature membrane rupture, and medical induction can result in PTB, but many PTBs lack an identifiable cause. Still, certain interventions (*access required), and namely those started before conception, have been identified to reduce the risk of PTB. These include maintaining a healthy lifestyle, exercising regularly, reducing stress, and addressing any underlying health conditions. Women planning to become pregnant can also reduce risk by utilizing contraception in order to space births at least 6 months apart. Those pursuing pregnancy, particularly through in vitro fertilization, might consider single-transfer embryos, as more than 50% of women pregnant with multiples give birth prematurely. Once pregnant, all expecting mothers should maintain proper prenatal care, including ceasing smoking and drug use, drinking alcohol, and taking nutritional supplements.

Some health care providers might conduct a PTB screening by taking a thorough medical history, measuring the cervix, or testing for infection. For mothers identified as high risk, early intervention, such as targeted prenatal care, nutritional counseling, progesterone supplementation, and medication may be recommended to reduce preterm birth risk. High risk women may also be referred to a maternal-fetal medicine specialist or to a dedicated PTB prevention clinic. It is also vitally important that women are informed and able to recognize the signs and symptoms of preterm labor, so they can seek the appropriate medical care as soon as possible.

Additional support can be sought from community-based programs and family-centered interventions. For example, the Creating Opportunities for Parent Empowerment (COPE) program has demonstrated positive impacts on maternal anxiety, depression, and self-efficacy. Support services and systems are instrumental to address/undergird the needs of mother, baby, and family as they navigate the challenges of PTB and healthy living.

Next Steps in Tackling PTB
A developing baby goes through important changes through the course of a pregnancy. That one in every 10 infants born in the United States is born prematurely—and that racial and ethnic disparities persist—is something that requires attention through federal research and policy. While the Eunice Kennedy Shriver National Institute for Child Health and Human Development supports research on PTB, additional, prioritized funding for its research networks could help reduce PTB rates and improve health equity. Additional research is needed to examine the risk factors and causes of PTB to develop effective preventive and intervention strategies, the long-term effects of PTB on adults, and the reason that preterm births occur disproportionately among certain racial and ethnic populations.

SWHR’s blog series on maternal and infant health disparities is supported by a grant from Covis Pharma. SWHR maintains editorial control and independence over blog content.