Racial, ethnic, and socioeconomic factors linked to preterm birth

Racial, ethnic, and socioeconomic factors linked to preterm birth | Image Credit: © WavebreakmediaMicro - © WavebreakmediaMicro - stock.adobe.com.

There are persistent disparities in preterm birth (PTB) rates across racial, ethnic, and socioeconomic groups, according to a recent study published in JAMA Network Open.¹

PTB leads to short- and long-term morbidity and mortality, recorded as the most common cause of infant mortality worldwide. PTB rates in the US range from 8% in Northeastern states to 13% in Southern states.² Additionally, racial and ethnic inequities are well documented.¹

Reported disparities in PTB indicate a need for improved understanding of factors associated with PTB across demographic groups. This information may increase utilization of effective PTB treatment that is often underused, as well as support the development of public health programs.

Investigators conducted a cohort study to evaluate inequities in PTB. Participants included singleton live births between January 1, 2011, and December 31, 2022, in California. Racial and ethnic grouping data was obtained from birth certificates from the California Department of Public Health Vital Records.

Socioeconomic status (SES) was determined based on insurance group, with categories including public and nonpublic. Best obstetric estimate was used to determine PTB, defined as gestational age of 22 to under 37 weeks.

Relevant medical records from the California Department of Health Care Access and Information were able to be linked to 2011 to 2021 birth records. This allowed data about maternal and infant characteristics, diagnoses, and procedures to be included in the analysis.

Variables included social determinants of health linked to PTB such as public health insurance, maternal place of birth, education level, number of prenatal care visits, smoking, drug or alcohol use, housing insecurity, and intimate partner violence. Physical and mental health factors were also evaluated.

There were 5,431,018 singleton live births included in the final analysis, 47.8% from Hispanic individuals, 27% White, 14.2% Asian, 4.9%% Black, 0.4% Pacific Islander, 0.3% Alaska Native, and 5.4% other racial or ethnic group. Being aged 18 to 34 years was reported in 76.6% and being born in the United States by 63.3%.

Of mothers, 39.4% were first-time parents, 43.1% used public health insurance, and 61.8% lived in urban areas. An increase in the PTB rate was reported, from 6.8% in 2011 to 7.5% in 2022. Of PTBs, 54.7% were spontaneous.

Significant PTB rates of 10.3%, 11.3%, and 9.3% were reported for Alaska Native, Black, and Pacific Islander patients, respectively, with public insurance. White individuals with nonpublic insurance had the lowest rate of 5.8%. Black patients with nonpublic insurance experienced a decrease in PTB prevalence from 9.1% in 2011 to 8.8% in 2022.

Most racial and ethnic groups experienced increases in PTB rates by insurance type between 2011 and 2022. Hispanic individuals with nonpublic insurance experienced an increase from 7.1% to 7.4%, and Alaska Native from 6.4% to 9.5%.

All racial and ethnic groups except for Pacific Islander had associations between increasing PTB rates and public insurance. Nonpublic insurance was also linked to increasing PTB rates in Asian, Hispanic, and White patients.

Factors linked to PTB included preexisting diabetes, preexisting hypertension, previous PTB, under 3 prenatal care visits, age over 34 years, gestational diabetes or hypertension, mental health condition, substance use, non-sexually transmitted infection or COVID-19 infection, and interpregnancy interval over 59 months.

Public insurance coverage for prenatal care was linked to reduced PTB risk among public insurance groups. However, the odds of pregnant people with public insurance having their prenatal care covered decreased over time.

These results highlighted inequities linked to PTB rates across racial, ethnic, and socioeconomic groups. Investigators concluded there is a need to enhance access to personalized pregnancy care and promote treatments to existing conditions.

References

1. Jelliffe-Pawlowski LL, Baer RJ, Oltman S, et al. Risk and protective factors for preterm birth among racial, ethnic, and socioeconomic groups in California. JAMA Netw Open. 2024;7(9):e2435887. doi:10.1001/jamanetworkopen.2024.35887
2. Percentage of births born preterm by state. Centers for Disease Control and Prevention National Center for Health Statistics. October 01, 2024. https://www.cdc.gov/nchs/pressroom/sosmap/preterm_births/preterm.htm