Kidsdata.org provides the following measures of infant mortality at the county level:

• Overall infant mortality rate, over three-year periods
• Infant mortality rate by leading causes of death,* over three-year periods
• Infant mortality rate by race/ethnicity, over five-year periods

Yearly rates and numbers of infant deaths also are available for California and the U.S.

Infant mortality is a key measure of a nation's health, reflecting socioeconomic conditions, maternal health, public health practices, and access to high-quality medical care, among other factors (1, 2). Major causes of infant mortality include birth defects, low birthweight and preterm birth, maternal pregnancy complications, and sudden infant death syndrome (3). Reducing infant mortality requires wide-ranging approaches that improve primary care prior to pregnancy, prenatal and well-baby preventive care, specialty care for infants born preterm and those with health conditions, breastfeeding support, and immunizations, along with empowered communities creating safe, healthy environments for all families (1).

Although the U.S. infant mortality rate has declined in recent decades, it remains higher than rates in most other developed countries (1, 2). The mortality rate among black infants is particularly high—more than double the rate for white and Asian groups, both nationally and in California (3, 4).

California's infant mortality rate declined by 40% between 1994 and 2016, from 7 infant deaths per 1,000 births to 4.2 per 1,000. Infant mortality rates statewide have followed but remained lower than U.S. rates over this period.

At the county level, infant mortality rates vary widely, from 2.6 (San Francisco) to 8.1 (Mendocino) among counties with data in 2014-16. Statewide, in 2014-16 and in previous years, the leading causes of infant death were birth defects and disorders related to low birthweight and preterm birth.

Disparities persist in infant mortality rates by race/ethnicity. Statewide, among groups with data in 2012-16, African American/black and multiracial infants died at rates of at least 9 per 1,000 births, whereas Asian/Pacific Islander and white infants had mortality rates below 4 per 1,000.

Some of the leading causes of infant mortality—e.g., birth defects, preterm birth, and sudden infant death syndrome (SIDS)—are preventable and can be addressed through public policy. California requires newborn screenings for potentially fatal genetic diseases, as early identification and treatment can help avert long-term health consequences and even death (1). Public and institutional policy also can address risk and protective factors for SIDS and preterm births by ensuring that women are in good health before conception, avoid smoking and substance use while pregnant, and forgo elective deliveries before 39 weeks of pregnancy, as well as broader strategies that address social determinants of health (2, 3).

Policy and program options that could reduce infant mortality include:

• Supporting evidence-based, culturally-appropriate communication and social marketing strategies to educate families about ways to promote infant health, including family planning, breastfeeding, immunizations, smoking cessation, and safe sleep practices (2, 3)
• Ensuring that key recommendations to prevent SIDS and other sleep-related infant deaths—including back sleeping, firm sleep surfaces, separate sleep surfaces for caregivers and infants, and smoking avoidance during pregnancy—reach a wide constellation of potential caregivers for infants (2, 4)
• Sustaining funding for substance use screening among pregnant women and for treatment designed specifically for pregnant women who use alcohol or drugs (2)
• Promoting research, education, and systems change aimed at reducing preterm labor and elective deliveries before 39 weeks of pregnancy (2, 3, 5)
• Increasing efforts to ensure that all women and infants, including those with special health care needs, receive quality medical care that is safe, timely, effective, efficient, and patient centered (2)
• Supporting a comprehensive approach to women's health, including integration of reproductive planning into women's routine health care, as good health before conception can improve pregnancy outcomes; this should include addressing mental/behavioral health and social support needs, as well as increasing the interval between pregnancies to at least 18 months (2, 6)
• Addressing underlying causes of infant mortality by focusing on social determinants of health; e.g., investing in under-resourced communities and efforts to ameliorate the effects of poverty on families during childbearing years (2)
• Supporting ongoing efforts to improve data systems for measuring health care access, quality, and outcomes for women and infants, as timely and accurate data are critical for informing policy and program decisions (2)
• Promoting collaboration across agencies and sectors at the local, state, and national levels to combine resources and expertise toward the common goal of reducing infant mortality (2)