Maternal Mortality and Perinatal Mortality

Maternal mortality is defined as the death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the duration and the site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management, but not from accidental or incidental causes.

In 2021, the maternal mortality rate in the United States was 32.9 deaths/100,000 live births, compared with a rate of 23.8 in 2020 and 20.1 in 2019 (1). The maternal mortality rate is higher in the United States than in European countries (eg, Germany, Netherlands, Poland, Spain, Sweden, Switzerland, United Kingdom). (See table Maternal Mortality Ratios in Selected Countries, 2020.)

Disparities by race and ethnicity in maternal mortality are significant worldwide. In the United States, rates in 2021 were highest in non-Hispanic Black women (69.9/100,000), compared with 28/100,000 in Hispanic women and 26.6/100,000 in non-Hispanic White women (1). In Brazil, maternal mortality is approximately 5 times higher in women of African descent than in White women (2). In the United Kingdom, the rate is more than 5 times higher in Black women than in White women (3).

Worldwide in 2013, the approximate percentage of maternal deaths occurred as follows (4):

• Antepartum: 25%

• Intrapartum and postpartum: 28%

• Late postpartum: 36%

• More than 42 days but less the 1 year after delivery: 12%

Maternal death statistics include direct obstetric and indirect causes. The most common causes of maternal death worldwide are (5)

• Hemorrhage, mostly postpartum hemorrhage (27%)

• Hypertensive disorders, including preeclampsia (14%)

• Abortion, including induced abortion, miscarriage, and ectopic pregnancy (8%)

• Complications of delivery (3%)

• Obstructed labor (3%)

• Sepsis (11%)

• Pulmonary embolism (3%)

• Preexisting medical conditions (15%)

• HIV infection (6%)

Usually, several factors contribute to maternal mortality (6), including

• Delay in deciding to seek care

• Delay in arriving at an appropriate health care facility (often because of distance or lack of transportation)

• Delay in receiving adequate care at a health care facility

Approximately 4 of 5 maternal deaths are preventable (7).

Perinatal mortality rate is the death of a fetus toward the end of a pregnancy or the death of a young infant. Definitions vary, but one definition of perinatal mortality rate is the number of deaths of infants < 7 days of age and fetal deaths at ≥ 28 weeks of gestation per 1000 live births.

The United States perinatal mortality rate in 2021 was 5.5 perinatal deaths per 1000 live births (8). The rate declined 30% from 1990 through 2011, was stable from 2011 through 2016, and declined 4% from 2017 through 2019.

Rates by race and ethnicity of the mother were

• 4.7 for children of non-Hispanic White women

• 9.5 for children of non-Hispanic Black women

• 4.9 for children of Hispanic women

The causes of perinatal death include causes of stillbirth and neonatal death. Causes of stillbirth may be fetal, maternal, or placental (see table Some Causes of and Risk Factors for Stillbirth).

The neonatal period is defined as the first 28 days of life. The majority of neonatal deaths (75%) occur within 7 days after birth (see World Health Organization: Newborn Mortality). In 2019, the major causes of neonatal death worldwide were preterm birth, childbirth-related complications (birth asphyxia or lack of breathing at birth), infections, and birth defects.