Stillbirth

What is stillbirth?

The definition of a stillbirth varies between countries.¹ In the United States, a stillbirth is generally defined as the death of a fetus at or after the 20th week of pregnancy.²

Stillbirths can occur at different points during pregnancy:^2,3

• Before labor. Death can happen inside the womb, before labor begins. This kind of stillbirth is called an antepartum stillbirth. In the United States, most stillbirths occur before the start of labor.⁴
• During labor. Death can also happen during labor. This is an intrapartum stillbirth. The causes of these stillbirths tend to be different than the causes of stillbirths before labor.⁴

Sometimes fetal deaths and infant deaths in the first week or first months of life are grouped together, even though they may occur at different times. When these deaths are looked at together, they are called perinatal (pronounced per-uh-NEYT-l) deaths, meaning “around the time of birth.” This is because some of the same problems and risks can lead to a death either before or just after birth.⁵

The death of a fetus before the 20th week of pregnancy is usually called a miscarriage or pregnancy loss. Learn more at the Pregnancy Loss A-Z topic.

Stillbirths in the United States

In 2006, the most recent year for which U.S. data are available, 1 out of every 167 pregnancies that made it to the 20th week ended with the death of the fetus before birth (that is, stillbirth before delivery). This translates to a total of nearly 26,000 deaths. About one-half of these stillbirths took place at 28 weeks of pregnancy or later.¹

The rate of stillbirths in the United States has been dropping since CDC began collecting data in 1950. For every 1,000 pregnancies that reached the 20th week during that year, more than 18 ended in stillbirth. The most recent data, collected in 2006, show that the rate has dropped to only about 6 stillbirths per 1,000 pregnancies that reached the 20th week.³

In the United States, there are similar numbers of stillbirth deaths and deaths of infants during their first year of life.^1,2 That is, about one-half of all deaths between 20 weeks of pregnancy and the first birthday occur before delivery.

On average, the U.S. stillbirth rate has been going down. For example, in 1985, almost 1 of every 127 pregnancies that made it to week 20 ended as a stillbirth before delivery;1 in 1950, the rate was about 1 of every 53 such pregnancies.³

Stillbirths are more than twice as likely in the pregnancies of Black women than in the pregnancies of White women in the United States.¹ Learn more about racial disparities in stillbirth.

Stillbirths Worldwide

Using the World Health Organization definition for stillbirth, which counts stillbirths only from 28 weeks of pregnancy, there were 2,600,000 stillbirths around the world in 2009, the most recent year for which worldwide data on stillbirth are available. This translates to an average of about one stillbirth at or after 28 weeks for every 45 births in 2009.⁴

The stillbirth rate is highest in South Asia and Sub-Saharan Africa (about 1 stillbirth at the 28th week of pregnancy or later per 33 births). The rate is lowest in high-income countries—fewer than 1 per 250 births.⁴

Stillbirth can happen in any pregnancy. Even after a thorough investigation, a probable or possible cause of stillbirth may not be found.¹

Even though there are certain risk factors for stillbirth, most individual stillbirths in the United States are not linked to any known risk factors that the woman has at the time she learns she is pregnant.²

Risks for Stillbirth in High-Income Countries

Studies have found many factors that increase risk for stillbirths in the United States and other high-income countries.

There are several types of factors, such as:^2,3,4

Maternal Characteristics

• Low socioeconomic status
• Older age (older than age 35)
• Smoking tobacco or marijuana during or just before pregnancy, or exposure to secondhand smoke during pregnancy
• Using illegal drugs before or during pregnancy

Maternal Medical Conditions

• Being overweight or obese
• Diabetes before pregnancy
• High blood pressure before pregnancy

Maternal Reproductive History

• Never having given birth before
• Previous stillbirth or small for gestational age infant
• Pregnancy with twins, triplets, or other multiples
• Assisted reproductive technology

Fetal Characteristics

• Small size in the fetus, given its age (sometimes called small for gestational age [SGA]). SGA can sometimes be due to growth restriction, a risky condition in which there is a problem with the pregnancy that prevents the fetus from growing as well as it could otherwise.

Risks for Stillbirth in Resource-Limited Countries

In developing countries, lack of access to obstetrical care contributes to high stillbirth rates. Most stillbirths in the developing world result from long and difficult labor, preeclampsia, and infections.⁵

A study conducted by the Global Network for Women’s and Children’s Health Research (funded by NICHD and the Bill and Melinda Gates Foundation) showed that providing basic newborn care training to birth attendants in low-income countries makes the stillbirth rate plummet.

As a result of the intervention, the rate of stillbirths dropped from 1 per every 43 deliveries to about 1 per 63 deliveries. The researchers believed this improvement was due to an increase in babies being resuscitated if they were not breathing at birth—a common problem that an untrained birth attendant might classify as a stillbirth. However, trained birth attendants can treat this problem using resuscitation techniques, including rubbing the newborn’s back.^6,7

In addition to risk factors that can increase the likelihood of a stillbirth, there are also factors that can cause or contribute to stillbirth. Remember, though, that in some cases of stillbirth, the cause of death remains unknown even after extensive testing.

To learn more about the possible causes of and contributors to stillbirth, the NICHD-supported Stillbirth Collaborative Research Network (SCRN) examined more than 500 stillbirths that occurred in 59 medical centers around the United States over 2½ 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.

The likely causes of and contributors to stillbirth identified by the study are listed below in order from most common to least common:¹

• Pregnancy and labor complications. Problems with the pregnancy likely caused almost one in three stillbirths. These complications included preterm labor, pregnancy with twins or triplets, and the separation of the placenta from the womb (also called “placental abruption;” the placenta provides nutrients and oxygen to the fetus). Pregnancy and labor complications were more common causes of stillbirths before week 24.
• Problems with the placenta. Almost one in four stillbirths were likely caused by problems with the placenta. One example of a placental problem that causes stillbirth is insufficient blood flow to the placenta. In the SCRN study, placental problems were the leading cause of stillbirths that took place before birth, and these deaths tended to occur after 24 weeks of pregnancy.
• Birth defects. In more than 1 of every 10 stillbirths, the fetus had a genetic or structural birth defect that probably or possibly caused the death.
• Infection. In more than 1 of every 10 stillbirths, the death was likely caused either by an infection in the fetus or in the placenta, or by a serious infection in the mother. Infections were a more common cause of death in stillbirths before week 24 than in those after.
• Problems with the umbilical cord. Problems with the umbilical cord were considered a probable or possible cause of about 1 in 10 stillbirths. For example, the cord can get knotted or squeezed, cutting off oxygen to the developing fetus. This cause of stillbirth tends to occur more toward the end of pregnancy.
• High blood pressure disorders. High blood pressure in the mother—whether due to chronic high blood pressure or to preeclampsia—also contributed to stillbirths. These types of stillbirths were more common in the end of the second trimester and the beginning of the third, compared with other parts of pregnancy.
• Medical complications in the mother. Problems with the mother’s health—such as diabetes—were considered a probable or possible cause in fewer than 1 in 10 of the stillbirths.

This research also showed that:

• Women who experienced financial, emotional, or other personal stress in the year before their delivery had an increased chance of having a stillbirth.
• Smoking tobacco or marijuana, taking prescription painkillers, or using illegal drugs during pregnancy is associated with double or even triple the risk of stillbirth.

Racial Disparities in Stillbirth

In the United States, stillbirths are more than twice as likely among Black women than among White women.² However, the reasons for this are not entirely clear.

The SCRN study found that the most common causes of stillbirth were different for Black women than for White women. Compared with stillbirths experienced by White women and Hispanic women, stillbirths to non-Hispanic Black women tended to be caused by infection or by complications of pregnancy and labor. Also, in Black women, stillbirth was more likely to occur during (rather than before) labor and earlier than 24 weeks into the pregnancy.¹

As mentioned above, SCRN research found that stillbirth was more than twice as likely among women who had experienced major financial, emotional, traumatic, or partner-related events in the year before delivery than among women who had not. Black women were more likely than women in general to have experienced at least three such stressful events in the past year.³

A pregnant mother may suspect stillbirth if she stops feeling the fetus kick or make other active movements inside her womb. But not feeling movement does not mean stillbirth in all cases.¹

Before birth, the only way to know for sure whether a stillbirth has occurred is to determine if the fetus’s heart is beating. This is often done using ultrasound,² a type of imaging that projects harmless sound waves through the mother’s body to create an image.

After birth, the infant is considered stillborn if he or she has “no signs of life,” which means the infant:³

• Is not breathing
• Has no heartbeat
• Has no pulsations in the umbilical cord, and
• Does not make voluntary movements

After a stillbirth, health care providers will try to determine why the fetus died and help the family cope with their loss.

Later on, if the family wants to try for another pregnancy, providers can help the mother understand and change any problems that might increase her risk of another stillbirth.

• Delivering the Fetus
• Examining the Fetus
• Managing Risk Factors
• Coping with Grief

Delivering the Fetus

If health care providers determine that the fetus has died while it is still in the womb, the next step is to deliver it. In general, this does not have to happen right away. Some parents might need time to cope with the news of their loss or to make arrangements. Others might prefer to complete the process as soon as possible.¹

Depending on how far along the pregnancy is and other considerations, health care providers usually will use one of these two methods to deliver the fetus:¹

• Induction. Providers will give the mother medicine to start labor. This method is used more often later in pregnancy.
• Dilation and evacuation. In this surgical procedure, providers first help the woman’s cervix open, or dilate. After about a day, the cervix will have opened and providers give the woman a medicine to keep her from feeling pain. Then, they insert instruments through the vagina and cervix into the womb to remove the fetus, the placenta, and other pregnancy material. Dilation and evacuation is only an option in the second trimester.

Examining the Fetus

After a stillbirth, it is important for providers to examine the body closely. Figuring out why the stillbirth occurred, if possible, can help providers and parents understand any risks that might affect future pregnancies.

Health care providers might examine a stillborn baby in three main ways:¹

• Inspecting the exterior of the fetus, placenta, and tissues. First, providers will examine the body and the tissues that surrounded and nourished the fetus inside the womb. This examination can reveal problems that could have caused or contributed to the death. They may weigh and measure the body and placenta to look for any growth problems. The health care provider might also photograph certain parts of the body or the placenta to put in the medical record or to show to a specialist.
• Examining individual cells and genetic material. Health care providers may ask parents’ permission to take samples of tissues from the body, the fluid that surrounded it in the womb (amniotic fluid), the placenta, and the umbilical cord. A laboratory will examine these samples for problems with cells, chromosomes, and DNA that could have caused or contributed to the death.
• Autopsy. Health care providers may ask parents’ permission to do an autopsy. (If providers do not bring it up, parents can also ask for an autopsy.) An autopsy involves opening up parts of the body to look for problems with the brain, heart, or other organs.

If parents prefer not to do an autopsy, the provider might ask for permission to take X-rays or conduct another type of imaging that shows inside the body. Imaging can help find the cause of death.¹

Managing Risk Factors

In many cases of stillbirth, there are no obvious risk factors. If there are factors that might increase the risk of another stillbirth in the future, and if the mother wants to have another child, she can work together with her providers to attempt to control the risks before getting pregnant again.¹ Learn more about risk factors for stillbirth.

Coping with Grief

Losing a baby to stillbirth can be a difficult experience for a family. Health care providers may offer ways to help parents come to terms with the death. Providers may also refer parents to a support group, religious leader, or counselor for help.¹ Read more about coping with grief after stillbirth.