Stillbirth

In the United States, stillbirth refers to the death of a fetus at or after the 20th week of pregnancy.¹ The death of a fetus before the 20th week of pregnancy is usually called a miscarriage or pregnancy loss.

Stillbirths can occur^{1, 2}:

• In the womb, before labor begins. This kind of stillbirth is also called an antepartum stillbirth. In the United States, slightly more than one-half of all stillbirths occur before the start of labor.³ Researchers may further categorize stillbirths into early (20 to 27 weeks of pregnancy) and late (28 to 36 weeks of pregnancy).
• During labor and delivery. These deaths may be called preterm stillbirths (occurring before 37 weeks of pregnancy) or term or intrapartum stillbirths (occurring at 37 weeks of pregnancy or later). The causes of stillbirths during labor and delivery tend to be different than the causes of stillbirths before labor.⁴

Some of the risk factors that can lead to stillbirth can also lead to a baby’s death just after birth.⁵ Learn more about risk factors for stillbirth.

How common is stillbirth?

Because of improvements in prenatal care, labor and delivery practices, and other factors, the rate of stillbirths in the United States has been dropping since the Centers for Disease Control and Prevention (CDC) began collecting data in 1950. However, rates have leveled off in recent years. Nonetheless, the rate of early stillbirth decreased by 3% for 2020 over 2019.³ The rate of late stillbirth was relatively unchanged from 2019. CDC maintains statistics on stillbirth in the United States.

Different countries and regions of the world have different stillbirth definitions, rates, and characteristics. The World Health Organization (WHO) defines stillbirth as fetal deaths at or after 28 weeks of pregnancy, but before or during birth.⁶ Using this definition, WHO estimates that there are more than 2 million stillbirths worldwide each year; about 40% of those occur before labor. Visit the WHO Stillbirth website to learn more.

Stillbirth can happen in any pregnancy. Even after an autopsy and other tests, the cause of stillbirth may not be known.¹

Research shows that some factors increase the risk for stillbirth among U.S. women, while other factors may increase risk among women worldwide. Here, we focus on U.S. risk factors. Many of these factors are not changeable, meaning there is nothing the pregnant woman, her family, or her health care provider can do to prevent the stillbirth.

Despite some known risk factors, most U.S. stillbirths occur in pregnant women who don’t have any risk factors.²

Risks for Stillbirth in the United States

Studies have found several factors that increase risk for stillbirths among pregnant women in the United States. However, these factors do not cause stillbirths; they only increase the chances that one will occur.^2,3,4,5

Features of the Pregnant Woman or the Pregnancy

• Low socioeconomic status
• Age 35 years or older
• Tobacco, marijuana, or alcohol use during or just before pregnancy⁶
• Exposure to secondhand smoke during pregnancy
• Illegal drug use before or during pregnancy⁷
• Black/African American race/ethnicity⁸
• Certain medical conditions or diseases, such as diabetes or high blood pressure before pregnancy and some infections⁹
• Having overweight or obesity
• Never having given birth before
• Previous pregnancy loss, miscarriage, or stillbirth
• Previous low birth weight or small infant for the stage of pregnancy, called small for gestational age (SGA)
• Pregnancy with twins, triplets, or other multiples
• Using assisted reproductive technology
• Stressful life events, such as major financial, emotional, traumatic, or partner-related events, in the year before pregnancy¹⁰
• Environmental exposures, including pollution and high temperatures¹¹

For the fetus, one known risk factor for stillbirth is small size, sometimes called SGA. SGA can result from growth restriction, a condition in which the fetus does not grow as quickly or as well as it should because of a problem with the pregnancy.

Researchers have identified several possible causes of or contributors to stillbirth. However, in many stillbirths, the cause remains unknown even after extensive testing.

Beginning in 2003, NICHD supported the Stillbirth Collaborative Research Network (SCRN) to learn more about the possible causes of and contributors to stillbirth. This first-of-its-kind resource examined more than 500 stillbirths at 59 medical centers around the United States over 5 years. In almost one quarter of these cases, the researchers could not determine a probable or even a possible cause of death. Also, many of the stillbirths had more than one likely cause.

Although analyses of data from the SCRN continue, the research identified the following possible causes of stillbirth in the United States, in order from most to least common¹:

• Pregnancy and labor complications, such as preterm labor; pregnancy with twins or triplets; and the separation of the placenta, which provides oxygen and nutrition to the fetus, from the womb (also called “placental abruption”).² These were more common causes of stillbirths before 24 weeks of pregnancy.
• Problems with the placenta, such as insufficient blood flow.² These were the leading causes of stillbirths in the womb, usually after 24 weeks of pregnancy.
• Fetal genetic problems and congenital anomalies, such as the neural tube defect anencephaly, in which most or all of the fetal brain and skull fails to develop.^2,3
• Infection in the pregnant woman, in the womb, in the placenta, or in the fetus. Stillbirths from Escherichia coli, group B streptococcus, and enterococcus were most common. Infection-related stillbirths were more common before 24 weeks of pregnancy.
• Problems with the umbilical cord, such as when it gets knotted or squeezed, cutting off oxygen to the fetus.⁴ Umbilical cord problems were more likely to cause term stillbirths and those during labor and delivery.
• High blood pressure disorders, including chronic high blood pressure before pregnancy and preeclampsia. These problems were more common causes of late stillbirths and term stillbirths than of early stillbirths.
• Medical problems in the pregnant woman, such as diabetes before pregnancy.

Racial Disparities in Stillbirth

In the United States, stillbirths are more than twice as likely among Black women than among White women.⁵ However, the reasons for this disparity are not entirely clear.

The SCRN study found that the most common causes of stillbirth were different for Black women than for White women and for Hispanic women. For non-Hispanic Black women in the SCRN, stillbirths were more likely to be caused by infection or by complications of pregnancy and labor. Also, the timing of stillbirth in Black women was different than that of White and Hispanic women: Stillbirths were more likely during labor and delivery and early (before 24 weeks) in pregnancy for non-Hispanic Black women.¹

As mentioned previously, SCRN research found that the risk for stillbirth was higher among women who had experienced major financial, emotional, traumatic, or partner-related events in the year before delivery. Black women were more likely than women in general to have experienced at least three such stressful events in the past year, which could help explain some of the disparity.⁶ However, it is more likely that the higher number of stillbirths among non-Hispanic Black women results from a combination of risk factors and causes.

Before delivery, the only way to diagnose a stillbirth is to determine if the fetus’s heart is beating. Providers often use ultrasound,¹ a type of imaging that projects harmless sound waves through the pregnant woman’s body to create an image, to look for the fetal heartbeat.

After labor and delivery, caregivers look for the following “signs of life”²:

• Breathing
• Heartbeat
• Pulsations in the umbilical cord
• Voluntary movements

If one or more of these signs are not present, life-saving measures will be taken, such as neonatal resuscitation methods. If these measures are not successful, the situation may be diagnosed as a stillbirth.

Fetal Movement Monitoring

In some cases, health care providers may recommend that pregnant women keep track of feelings of fetal movements or kicks. It is important to note, however, that the absence of feelings of fetal movement does not mean stillbirth has occurred in all cases.³ In some first-time pregnancies, for example, movement is difficult to detect.

The Count the Kicks campaign aims to raise awareness about fetal movement and possible prevention of stillbirth. They offer an app, educational information, and data for providers about counting fetal kicks and movements.

Care after a stillbirth depends on when it occurs.

If a stillbirth occurs in the womb, then the fetus and the placenta need to be removed or delivered. If it occurs during labor or delivery, then the placenta will still need to be removed or delivered.

Health care providers will then try to determine a cause for the stillbirth by examining the fetus, the placenta, and other tissues from the pregnancy and possibly by performing an autopsy.

At the same time, providers will offer support to help the family cope with their loss.

When or if the family wants to try for another pregnancy, providers can work with them to discuss any risk factors and possible ways to prevent another stillbirth.

Learn more about each aspect of managing a stillbirth.