Progress Largely Stalled on Preterm Births and Babies Born With a Low Birth Weight

Major progress to reduce the per­cent­age of U.S. babies born pre­ma­ture­ly or with a low birth weight has not occurred in decades, and racial inequities remain a seri­ous pub­lic health concern.

What Is the Sig­nif­i­cance of Preterm Birth and Low Birth Weight?

Preterm birth (before 37 com­plet­ed weeks of ges­ta­tion) and low birth weight (less than 5.5 pounds) are lead­ing caus­es of infant mor­tal­i­ty in the U.S., and these babies are at high­er risk of long-term health and devel­op­men­tal prob­lems. Many fac­tors can increase the like­li­hood of a baby being born pre­ma­ture­ly or at a low birth weight, such as mater­nal smok­ing or sub­stance use issues, low socioe­co­nom­ic sta­tus, inad­e­quate pre­na­tal care, short spac­ing between births, expe­ri­ences of racism, vio­lence or abuse, envi­ron­men­tal expo­sures, pre­vi­ous preg­nan­cy com­pli­ca­tions, car­ry­ing more than one baby, being over­weight or under­weight, liv­ing in rur­al areas and more. Addi­tion­al­ly, research has long shown inequities by race and eth­nic­i­ty for preterm birth and low birth weight, par­tic­u­lar­ly for Black infants.

What Are the Lat­est Preterm Birth and Low Birth Weight Findings?

Accord­ing to new data in the KIDS COUNT^® Data Cen­ter, the per­cent­age of U.S. infants born preterm has not changed in recent years, hold­ing steady at 12% from 2017 to 2020. In fact, this fig­ure has hov­ered in the 11% to 13% range since 1990. Reduc­ing preterm births has been a pub­lic health pri­or­i­ty for many years, and the fed­er­al gov­ern­ment is cur­rent­ly pur­su­ing this pri­or­i­ty as part of its Healthy Peo­ple 2030 Objec­tives.

The per­cent­age of U.S. babies born with a low birth weight declined slight­ly to 8.2% in 2020, after stag­nat­ing at 8.3% the pre­vi­ous three years. This fig­ure has fluc­tu­at­ed between 8% and 8.3% since 2004, pri­or to which it had been ris­ing for more than a decade, from 7% in 1990 to 7.9% in 2003. The per­cent­age of very low birth-weight infants (less than 3.4 pounds) also inched down slight­ly in 2020, to 1.3%, after hold­ing at 1.4% for 10 years.

Racial Inequities Remain an Urgent Concern

Despite grow­ing research, advo­ca­cy, and pub­lic health efforts, Black moth­ers and babies con­tin­ue to be at high­est risk of adverse birth out­comes. The KIDS COUNT Data Cen­ter pro­vides data on low birth-weight infants by race and eth­nic­i­ty, illus­trat­ing these ongo­ing inequities, with 13.8% of Black new­borns at a low birth weight in 2020, more than twice the per­cent­age for white babies (6.8%). Fig­ures for oth­er infants of col­or are also high­er than those of white infants: 8.9% for new­borns with two or more races, 8.5% for Asians and Pacif­ic Islanders, 7.9% for Amer­i­can Indi­ans and 7.4% for Lati­nos. The nation­al aver­age falls in between these groups at 8.2%.

Low Birth Weight and Preterm Births Vary by Geography

Con­sis­tent with research on social deter­mi­nants of health, geog­ra­phy and birth out­comes are strong­ly cor­re­lat­ed. Accord­ing to the KIDS COUNT Data Center’s preterm birth and low birth weight data by state, Mis­sis­sip­pi, Louisiana and Alaba­ma con­sis­tent­ly have had the high­est per­cent­ages of both preterm births and low birth-weight babies over the past decade. For instance, in 2020, 11.8% of Mis­sis­sip­pi babies were born with a low birth weight and 17% were born pre­ma­ture, while 10.9% of Louisiana infants had a low birth weight and 18% were preterm, fol­lowed by Alaba­ma with 10.8% and 15%, respec­tive­ly. On the oth­er end of the spec­trum, Ore­gon had the low­est per­cent­ages for both mea­sures in 2020, with 6.5% low birth-weight babies and 9% pre­ma­ture births.

The KIDS COUNT Data Cen­ter also offers data by ter­ri­to­ry and city. Puer­to Rico has improved both of these birth out­comes over the last decade, although its per­cent­ages con­tin­ue to be fair­ly high, with 10.2% of infants born at a low birth weight and 14% born pre­ma­ture­ly in 2020. Among U.S. cities with data for both mea­sures in 2020, Detroit, Mil­wau­kee, Mem­phis and Bal­ti­more had the high­est per­cent­ages of low birth-weight babies and preterm births. Detroit and Mem­phis have ranked in the top five cities with the high­est per­cent­ages for both mea­sures since 2015.

Action to Reduce Preterm Births and Low Birth Weight

More can be done across mul­ti­ple sec­tors to pre­vent preterm births and low birth weight and to elim­i­nate inequities. Exam­ples of strategies:

• Pro­mote the health of repro­duc­tive age indi­vid­u­als before, dur­ing and after preg­nan­cy, includ­ing help­ing women to quit smoking
• Improve access to time­ly, cul­tur­al­ly appro­pri­ate pre­na­tal care, espe­cial­ly for women of col­or and those in low-income and rur­al communities
• Encour­age spac­ing preg­nan­cies apart by at least 18 months
• Address social deter­mi­nants of health, includ­ing struc­tur­al racism and sys­temic bar­ri­ers to high-qual­i­ty health care

Access More Birth Data in the KIDS COUNT Data Center

See addi­tion­al indi­ca­tors on births and birth out­comes, such as:

• Births to women receiv­ing late or no pre­na­tal care, by race and ethnicity
• Births to moth­ers who smoked dur­ing pregnancy
• Births to moth­ers with less than 12 years of education
• Teen births by age group, by race and ethnicity
• Infant mor­tal­i­ty, by race and ethnicity

The Data Center’s low birth weight indi­ca­tor is also includ­ed in the Foundation’s Race for Results^® series and in the KIDS COUNT Child Well-Being Index, as part of the KIDS COUNT Data Book.

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