Infant Mortality by Selected Maternal Characteristics and Race and Hispanic Origin in the United States, 2019-2021.

Objectives- This report presents infant mortality rates for selected maternal characteristics (prepregnancy body mass index, cigarette smoking during pregnancy, receipt of Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) benefits during pregnancy, timing of prenatal care, and source of payment for delivery) for the five largest maternal race and Hispanic-origin groups in the United States for combined years 2019-2021. Methods-Descriptive tabulations based on data from the linked birth/infant death files for 2019-2021 are presented. The linked birth/infant death file is based on birth and death certificates registered in all 50 states and the District of Columbia. Infant mortality rates are presented for each maternal race and Hispanic-origin group overall and by selected characteristics. Results-Infant mortality rates varied across the five largest maternal race and Hispanic-origin groups and by selected maternal characteristics. For most race and Hispanic-origin groups, mortality rates were higher among infants of women with prepregnancy obesity compared with those of women who were normal weight, and were higher for infants of women who smoked cigarettes during pregnancy, received late or no prenatal care, or were covered by Medicaid as the source of payment for delivery. Overall, mortality rates were higher for infants of women who received WIC during pregnancy, but results varied across race and Hispanic-origin groups. Mortality rates for the maternal characteristics examined were generally highest among infants of Black non-Hispanic and American Indian and Alaska Native non-Hispanic women and lowest for Asian non-Hispanic women.

Trends and Characteristics in Maternal Syphilis Rates During Pregnancy: United States, 2016-2022.

After reaching historic lows in 2000 and 2001, rates of primary and secondary syphilis in the overall U.S. population have increased nearly every year through 2022 (1). For 2017-2022, rates of syphilis for women of reproductive age and congenital syphilis (a disease that occurs when a mother with syphilis passes the infection on to her baby during pregnancy) increased by more than 250% (1,2). Congenital syphilis can cause adverse pregnancy outcomes such as fetal and neonatal death, low birthweight, preterm birth, and brain and nerve disorders (2). This report presents trends in maternal syphilis rates in women giving birth in the United States for 2016-2022 by selected maternal demographic and health factors.

Infant Mortality in the United States, 2021: Data From the Period Linked Birth/Infant Death File.

Objective-This report presents 2021 infant mortality statistics by age at death, maternal race and Hispanic origin, maternal age, gestational age, leading causes of death, and maternal state of residence. Trends in infant mortality are also examined. Methods-Descriptive tabulations of data are presented and interpreted for infant deaths and infant mortality rates using the 2021 period linked birth/infant death file. The linked birth/infant death file is based on birth and death certificates registered in all 50 states and the District of Columbia. Results-A total of 19,928 infant deaths were reported in the United States in 2021, up 2% from 2020. The U.S. infant mortality rate was 5.44 infant deaths per 1,000 live births, essentially unchanged from the rate of 5.42 in 2020. The neonatal mortality rate was essentially unchanged from 3.56 in 2020 to 3.49 in 2021, but the postneonatal mortality rate increased from 1.86 to 1.95. The overall infant mortality rate increased for infants of Asian non-Hispanic women and declined for infants of Dominican women in 2021 compared with 2020; changes in rates for the other race and Hispanic-origin groups were not significant. Infants of Black non-Hispanic women had the highest mortality rate (10.55) in 2021, followed by infants of Native Hawaiian or Pacific Islander non-Hispanic and American Indian or Alaska Native non-Hispanic (7.76 and 7.46, respectively), Hispanic (4.79), White non-Hispanic (4.36), and Asian non-Hispanic (3.69) women. By gestational age, infants born very preterm (less than 28 weeks of gestation) had the highest mortality rate (353.76), 170 times as high as that for infants born at term (37-41 weeks of gestation) (2.08). The five leading causes of infant death in 2021 were the same as in 2020. Infant mortality rates by state for 2021 ranged from a low of 2.77 in North Dakota to a high of 9.39 in Mississippi.

Trends and Characteristics in Prepregnancy Diabetes: United States, 2016-2021.

Objectives-This report presents data on trends for prepregnancy diabetes mellitus (PDM), diabetes diagnosed before pregnancy, in mothers giving birth in the United States for 2016-2021, and rates by selected maternal characteristics for 2016 and 2021.

Infant Mortality in the United States, 2020: Data From the Period Linked Birth/Infant Death File.

Objectives-This report presents 2020 infant mortality statistics by age at death, maternal race and Hispanic origin, maternal age, gestational age, leading causes of death, and maternal state of residence. Trends in infant mortality are also examined.

Disparities in infant mortality by maternal race and Hispanic origin, 2017-2018.

Disparities in infant mortality by race and Hispanic origin groups continue to persist in the United States. Maternal and infant characteristics known to be associated with infant mortality vary by race and ethnicity. This report describes racial and ethnic disparities in infant mortality in the United States using the 2017-2018 cohort linked birth/infant death files from the National Vital Statistics System. Distributions of births and infant mortality rates are described by selected maternal and infant characteristics. Adjusted rates and rate ratios from logistic regression models, compared to unadjusted rates and ratios, show the extent to which race and Hispanic origin disparities would be attenuated if all groups had the same distributions of select maternal and infant factors. Results support the premise that the different distributions of several variables across racial/ethnic groups, most notably gestational age, account for a significant portion of the disparities in infant mortality between racial/ethnic groups.

Trends and Characteristics in Gestational Diabetes: United States, 2016-2020.

Objectives-This report presents data on trends for gestational diabetes mellitus (GDM) among women giving birth in the United States from 2016 through 2020, and rates by selected maternal and newborn characteristics for 2016, 2019, and 2020.

Infant Mortality in the United States, 2019:Data From the Period Linked Birth/Infant Death File.

Objectives-This report presents 2019 infant mortality statistics by age at death, maternal race and Hispanic origin, maternal age, gestational age, leading causes of death, and maternal state of residence. Trends in infant mortality are also examined.

Drug-involved Infant Deaths in the United States, 2015-2017.

This report describes drug-involved infant deaths in the United States for 2015-2017 by type of drug involved and selected maternal and infant characteristics. Deaths are grouped according to whether drugs were the underlying or a contributing cause of death.

Infant Mortality by Maternal Prepregnancy Body Mass Index: United States, 2017-2018.

Objective-This report presents 2017-2018 infant mortality rates in the United States by maternal prepregnancy body mass index, and by infant age at death, maternal age, and maternal race and Hispanic origin. Methods-Descriptive tabulations of infant deaths by maternal and infant characteristics are presented using the 2017-2018 linked period birth/infant death files; the linked period birth/infant death file is based on birth and death certificates registered in all states and the District of Columbia. The 2017 linked birth/infant death file is the first year that national data on maternal prepregnancy body mass index were available. Results-Total infant, neonatal, and postneonatal mortality rates were lowest for infants of women who were normal weight prepregnancy, and then rose with increasing prepregnancy body mass index. Total, neonatal, and postneonatal rates were higher for infants of women who were underweight prepregnancy compared with infants of women who were normal or overweight before pregnancy. Mortality rates for infants of underweight women were generally, but not exclusively, lower than those of infants born to women with obesity. Infants born to women of normal weight generally had lower mortality rates than infants born to women who had obesity prepregnancy for all maternal age and race and Hispanic-origin groups.

Infant Mortality in the United States, 2018: Data From the Period Linked Birth/Infant Death File.

Objectives-This report presents 2018 infant mortality statistics by age at death, maternal race and Hispanic origin, maternal age, gestational age, leading causes of death, and maternal state of residence. Trends in infant mortality are also examined. Methods-Descriptive tabulations of data are presented and interpreted for infant deaths and infant mortality rates using the 2018 period linked birth/infant death file; the linked birth/infant death file is based on birth and death certificates registered in all states and the District of Columbia. Results-A total of 21,498 infant deaths were reported in the United States in 2018. The U.S. infant mortality rate was 5.67 infant deaths per 1,000 live births, lower than the rate of 5.79 in 2017 and an historic low in the country. The neonatal and post neonatal mortality rates for 2018 (3.78 and 1.89, respectively) demonstrated a nonsignificant decline compared with 2017 (3.85 and 1.94, respectively). The 2018 mortality rate declined for infants of Hispanic women compared with the 2017 rate; changes in rates for other race and Hispanic-origin groups were not statistically significant. The 2018 infant mortality rate for infants of non-Hispanic black women (10.75) was more than twice as high as that for infants of non-Hispanic white (4.63), non-Hispanic Asian (3.63), and Hispanic women (4.86). Infants born very preterm (less than 28 weeks of gestation) had the highest mortality rate (382.20), 186 times as high as that for infants born at term (37-41 weeks of gestation) (2.05). The five leading causes of infant death in 2018 were the same as in 2017; cause-of-death rankings and mortality rates varied by maternal race and Hispanic origin. Infant mortality rates by state for 2018 ranged from a low of 3.50 in New Hampshire to a high of 8.41 in Mississippi.

Effects of Changes in Maternal Age Distribution and Maternal Age-specific Infant Mortality Rates on Infant Mortality Trends: United States, 2000-2017.

Objectives-This report assesses the contributions of the changing maternal age distribution and maternal age-specific infant mortality rates on overall and race and Hispanic origin-specific infant mortality rates in the United States from 2000 to 2017. Methods-The analyses used 2000-2017 linked birth and infant death data from the National Vital Statistics System. Age-adjusted infant mortality rates, based on the 2000 U.S. maternal age distribution, were calculated for each year. These rates were compared with crude rates for all births and for specific race and Hispanic-origin groups. Decomposition analysis was used to estimate the proportion of the decline due to changes in maternal age distribution and in age-specific mortality rates. Results-During 2000-2017, the age of women giving birth rose as infant mortality rates declined, although unevenly across maternal age groups. The maternal age-adjusted infant mortality rate in 2017 was 6.13 compared with the crude rate of 5.79, resulting in a 0.34 percentage point difference. Changes in the maternal age distribution accounted for 31.3% of the decline in infant mortality rates for all births and for births to non-Hispanic white women, and for 4.8% of the decline in births to non-Hispanic black women. Declines in age-specific mortality rates accounted for the remainder of the decline for these groups and for all of the decline in births to Hispanic women. Conclusion-Changes in the age distribution of women giving birth accounted for about one-third of the decline in infant mortality rates from 2000 through 2017; declines in maternal age-specific mortality rates accounted for about two-thirds of this decline. These patterns varied by race and Hispanic origin.

Trends and Characteristics of Sexually Transmitted Infections During Pregnancy: United States, 2016-2018.

Objectives-This report presents data on recent trends for three sexually transmitted infections (STIs)-chlamydia, gonorrhea, and syphilis-reported among women giving birth in the United States from 2016 through 2018, and rates by selected characteristics for 2018. Methods-Data are from birth certificates and are based on 100% of births registered in the United States for 2016, 2017, and 2018. Birth certificate data on infections during pregnancy are recommended to be collected from the mother's medical records (1). Mothers are to be reported as having an infection if there is a confirmed diagnosis or documented treatment for the infection in their medical record (2). Results-Among women giving birth in 2018, the overall rates of chlamydia, gonorrhea, and syphilis were 1,843.9, 310.2, and 116.7 per 100,000 births, respectively. The rates for these STIs increased 2% (chlamydia), 16% (gonorrhea), and 34% (syphilis) from 2016 through 2018. In 2018, rates of chlamydia and gonorrhea decreased with advancing maternal age, whereas those for syphilis decreased with maternal age through 30-34 years and then increased for women aged 35 and over. In 2018, rates of all three STIs were highest for non-Hispanic black women, women who smoked during pregnancy, women who received late or no prenatal care, and women for whom Medicaid was the principal source of payment for the delivery. Among women aged 25 and over, rates of each of the STIs decreased with increasing maternal education.

Infant Mortality Attributable to Birth Defects - United States, 2003-2017.

Birth defects are a leading cause of infant mortality in the United States, accounting for 20.6% of infant deaths in 2017 (1). Rates of infant mortality attributable to birth defects (IMBD) have generally declined since the 1970s (1-3). U.S. linked birth/infant death data from 2003-2017 were used to assess trends in IMBD. Overall, rates declined 10% during 2003-2017, but decreases varied by maternal and infant characteristics. During 2003-2017, IMBD rates decreased 4% for infants of Hispanic mothers, 11% for infants of non-Hispanic black (black) mothers, and 12% for infants of non-Hispanic white (white) mothers. In 2017, these rates were highest among infants of black mothers (13.3 per 10,000 live births) and were lowest among infants of white mothers (9.9). During 2003-2017, IMBD rates for infants who were born extremely preterm (20-27 completed gestational weeks), full term (39-40 weeks), and late term/postterm (41-44 weeks) declined 20%-29%; rates for moderate (32-33 weeks) and late preterm (34-36 weeks) infants increased 17%. Continued tracking of IMBD rates can help identify areas where efforts to reduce IMBD are needed, such as among infants born to black and Hispanic mothers and those born moderate and late preterm (32-36 weeks).

Infant Mortality in the United States, 2017: Data From the Period Linked Birth/Infant Death File.

Objectives-This report presents 2017 infant mortality statistics by age at death, maternal race and Hispanic origin, maternal age, maternal state of residence, gestational age, and leading causes of death. Trends in infant mortality are also examined. Methods-Descriptive tabulations of data are presented and interpreted for infant deaths and infant mortality rates using the 2017 period linked birth/infant death file; the linked birth/infant death file is based on birth and death certificates registered in all states and the District of Columbia. Results-A total of 22,341 infant deaths were reported in the United States in 2017. The U.S. infant mortality rate was 5.79 infant deaths per 1,000 live births, not statistically different from the rate of 5.87 in 2016. The neonatal and postneonatal mortality rates for 2017 (3.85 and 1.94, respectively) were also essentially unchanged from 2016. The 2017 infant mortality rate for infants of non-Hispanic black women (10.97) was more than twice as high as that for infants of non-Hispanic white (4.67), non-Hispanic Asian (3.78), and Hispanic (5.10) women. Infant mortality rates by state for 2017 ranged from a low of 3.66 in Massachusetts to a high of 8.73 in Mississippi. Infants born very preterm (less than 28 weeks of gestation) had the highest mortality rate (384.39), 183 times as high as that for infants born at term (37-41 weeks of gestation) (2.10). The five leading causes of infant death in 2017 were the same as in 2016; cause of death rankings and mortality rates varied by maternal race and Hispanic origin. Preterm-related causes of death accounted for 34% of the 2017 infant deaths, unchanged from 2016.

Maternal Characteristics and Infant Outcomes in Appalachia and the Delta.

Objectives-This report compares maternal characteristics and outcomes for infants born to mothers in Appalachia, the Delta, and the rest of the United States. Methods-The 2017 vital statistics natality file and the 2016-2017 linked birth/infant death data files were used to compare maternal characteristics (e.g., race and Hispanic origin, age, and marital status) of women who gave birth in Appalachia, the Delta, and the rest of the United States. Comparisons of infant outcomes (preterm, low birthweight, and infant mortality) across the three regions were made overall and within categories of these maternal characteristics. Results-Characteristics of women who gave birth differed across the three regions. Women in the Delta were most likely to be teenagers, unmarried, and not have a college degree, followed by women in Appalachia, and then by women in the rest of the United States. Overall and within most categories of maternal characteristics, infants born in the Delta were more likely to be preterm (12.37%) or low birthweight (10.75%) and were more likely to die in their first year of life (8.17 infant deaths per 1,000 live births) than those born in Appalachia (10.75%, 8.87%, and 6.82, respectively), while those born in the rest of the United States were the least likely (9.78%, 8.14%, and 5.67, respectively). Conclusions-Maternal characteristics associated with poor infant outcomes are most common among women who give birth in the Delta, followed by women in Appalachia, and then the rest of the United States. Within most categories of these maternal characteristics, infants born in the Delta have the worst outcomes, followed by those born in Appalachia, and then those born in the rest of the United States.

Trends in Fertility and Mother's Age at First Birth Among Rural and Metropolitan Counties: United States, 2007-2017.

Since the most recent peak in the total fertility rate (the estimated number of lifetime births expected per 1,000 women) in 2007, the United States has experienced a decreasing total fertility rate and an increasing mean, or average, age of mothers at first birth (1-4). Previous research shows rural areas have persistently higher fertility and worse birth outcomes compared with metropolitan (metro) areas (2,5-8). This report describes trends and differences in total fertility rates and mean maternal age at first birth overall, and by race and Hispanic origin, between rural and small or medium metro, and rural and large metro counties, from 2007 through 2017.

Infant Mortality by Age at Death in the United States, 2016.

Infant mortality is an important public health measure in the United States and other countries (1-3). The United States' infant mortality rate started to decline in 2007 (the most recent high), but has remained relatively unchanged in recent years (4,5). Previous research shows differences in infant mortality rates by age at death (i.e., neonatal, or deaths to infants aged 0-27 days, and postneonatal, or deaths to infants aged 28-364 days), age and race and Hispanic origin of the mother, and leading causes of death (4-6). This report examines infant mortality rates for the United States by age at death in 2016, by maternal age and race and Hispanic origin, and for the five leading causes of neonatal and postneonatal mortality.

Differences Between Rural and Urban Areas in Mortality Rates for the Leading Causes of Infant Death: United States, 2013-2015.

The leading causes of infant death vary by age at death but were consistent from 2005 to 2015 (1-6). Previous research shows higher infant mortality rates in rural counties compared with urban counties and differences in cause of death for individuals aged 1 year and over by urbanization level (4,5,7,8). No research, however, has examined if mortality rates from the leading causes of infant death differ by urbanization level. This report describes the mortality rates for the five leading causes of infant, neonatal, and postneonatal death in the United States across rural, small and medium urban, and large urban counties defined by maternal residence, as reported on the birth certificate for combined years 2013-2015.

State Variations in Infant Mortality by Race and Hispanic Origin of Mother, 2013-2015.

Infant mortality has long been a basic measure of public health for countries around the world (1­3). While the overall infant mortality rate in the United States is lower than a decade ago, declining 14% from 6.86 infant deaths per 1,000 live births in 2005, a recent high, to 5.90 in 2015, the rate in 2015 was not statistically different from that in 2014 (5.82) (4­6). The variability in infant mortality rates by state and by race and Hispanic origin continues to receive attention (7,8). This report uses linked birth and infant death data from 2013 through 2015 to describe infant mortality rates in the United States by state, and for race and Hispanic-origin groups by state.