Stillbirth

**Stillbirth** is typically defined as fetal death at or after 20 to 28 weeks of pregnancy (depending on the source). It results in a baby born without signs of life. The World Health Organization (WHO) advocates for the usage of ICD-10 definitions of stillbirth to be able to compare data internationally. The WHO uses the ICD-10 definitions of "late fetal deaths" as their definition of stillbirth. A stillbirth can result in the feeling of guilt or grief in the mother. The term is in contrast to miscarriage, which is an early pregnancy loss, and live birth, where the baby is born alive, even if it dies shortly after.

Often the cause is unknown. Causes may include pregnancy complications such as pre-eclampsia and birth complications, problems with the placenta or umbilical cord, birth defects, infections such as malaria and syphilis, and poor health in the mother. Risk factors include a mother's age over 35, smoking, drug use, use of assisted reproductive technology, and first pregnancy. Stillbirth may be suspected when no fetal movement is felt. Confirmation is by ultrasound.

Worldwide prevention of most stillbirths is possible with improved health systems. About half of stillbirths occur during childbirth, with this being more common in the developing than developed world. Otherwise depending on how far along the pregnancy is, medications may be used to start labor or a type of surgery known as dilation and evacuation may be carried out. Following a stillbirth, women are at higher risk of another one; however, most subsequent pregnancies do not have similar problems. Depression, financial loss, and family breakdown are known complications.

Worldwide in 2015 there were about 2.6 million stillbirths that occurred after 28 weeks of pregnancy (about 1 for every 45 births). They occur most commonly in the developing world, particularly South Asia and Sub-Saharan Africa. In the United States for every 167 births there is one stillbirth. Although stillbirth rates are declining, they are declining at a slower rate since the 2000s. By 2030, the WHO hopes to hit a goal of only having 12 stillbirths per 1000 births in each country worldwide.

## Causes

As of 2016, there is no international classification system for stillbirth causes. The causes of a large percentage of stillbirths is unknown, even in cases where extensive testing and an autopsy have been performed. A rarely used term to describe these is "sudden antenatal death syndrome" or SADS, a phrase coined in 2000. Many stillbirths occur at full term to apparently healthy mothers, and a postmortem evaluation reveals a cause of death in about 40% of autopsied cases.

About 10% of cases are believed to be due to obesity, high blood pressure, or diabetes.

Other risk factors include:

* bacterial infection, like syphilis
* malaria
* birth defects, especially pulmonary hypoplasia
* chromosomal aberrations
* growth restriction
* intrahepatic cholestasis of pregnancy
* maternal diabetes
* maternal consumption of recreational drugs (such as alcohol, nicotine, etc.) or pharmaceutical drugs contraindicated in pregnancy
* postdate pregnancy
* placental abruptions
* physical trauma
* radiation poisoning
* Rh disease
* celiac disease
* female genital mutilation

* umbilical cord accidents
	+ *Prolapsed umbilical cord* – Prolapse of the umbilical cord happens when the fetus is not in a correct position in the pelvis. Membranes rupture and the cord is pushed out through the cervix. When the fetus pushes on the cervix, the cord is compressed and blocks blood and oxygen flow to the fetus. The mother has approximately 10 minutes to get to a doctor before there is any harm done to the fetus.
	+ *Monoamniotic twins* – These twins share the same placenta and the same amniotic sac and therefore can interfere with each other's umbilical cords. When entanglement of the cords is detected, it is highly recommended to deliver the fetuses as early as 31 weeks.
	+ *Umbilical cord length* - A short umbilical cord (<30 cm) can affect the fetus in that fetal movements can cause cord compression, constriction and ruptures. A long umbilical cord (>72 cm) can affect the fetus depending on the way the fetus interacts with the cord. Some fetuses grasp the umbilical cord but it is yet unknown as to whether a fetus is strong enough to compress and stop blood flow through the cord. Also, an active fetus, one that frequently repositions itself in the uterus can cause entanglement with the cord. A hyperactive fetus should be evaluated with ultrasound to rule out cord entanglement.
	+ *Cord entanglement* - The umbilical cord can wrap around an extremity, the body or the neck of the fetus. When the cord is wrapped around the neck of the fetus, it is called a nuchal cord. These entanglements can cause constriction of blood flow to the fetus. These entanglements can be visualized with ultrasound.
	+ *Torsion* – This term refers to the twisting of the umbilical around itself. Torsion of the umbilical cord is very common (especially in equine stillbirths) but it is not a natural state of the umbilical cord. The umbilical cord can be untwisted at delivery. The average cord has 3 twists.

A mother sleeping on her back after 28 weeks of pregnancy may be a risk factor for stillbirth.

After a stillbirth there is a 2.5% risk of another stillbirth in the next pregnancy (an increase from 0.4%).

## Diagnosis

It is unknown how much time is needed for a fetus to die. Fetal behavior is consistent and a change in the fetus' movements or sleep-wake cycles can indicate fetal distress. A decrease or cessation in sensations of fetal activity may be an indication of fetal distress or death, though it is not entirely uncommon for a healthy fetus to exhibit such changes, particularly near the end of a pregnancy when there is considerably less space in the uterus than earlier in pregnancy for the fetus to move about. Still, medical examination, including a nonstress test, is recommended in the event of any type of any change in the strength or frequency of fetal movement, especially a complete cease; most midwives and obstetricians recommend the use of a kick chart to assist in detecting any changes. Fetal distress or death can be confirmed or ruled out via fetoscopy/doptone, ultrasound, and/or electronic fetal monitoring. If the fetus is alive but inactive, extra attention will be given to the placenta and umbilical cord during ultrasound examination to ensure that there is no compromise of oxygen and nutrient delivery.

Some researchers have tried to develop models to identify early on pregnant women who may be at high risk of having a stillbirth.

### Definition

There are a number of definitions for stillbirth. To allow comparison, the World Health Organization uses the ICD-10 definitions and recommends that any baby born without signs of life at greater than or equal to 28 completed weeks' gestation be classified as a stillbirth. Others use greater than any combination of 16, 20, 22, 24, or 28 weeks gestational age or 350 g, 400 g, 500 g, or 1000 g birth weight may be considered stillborn.

The term is often used in distinction to live birth (the baby was born alive, even if it died shortly thereafter) or miscarriage (early pregnancy loss). The word miscarriage is often used incorrectly to describe stillbirths. The term is mostly used in a human context, however the same phenomenon can occur in all species of placental mammals.

### Constricted umbilical cord

When the umbilical cord is constricted (q.v. "accidents" above), the fetus experiences periods of hypoxia, and may respond by unusually high periods of kicking or struggling, to free the umbilical cord. These are sporadic if constriction is due to a change in the fetus' or mother's position, and may become worse or more frequent as the fetus grows. Extra attention should be given if mothers experience large increases in kicking from previous childbirths, especially when increases correspond to position changes.

Regulating high blood pressure, diabetes and drug use may reduce the risk of a stillbirth. Umbilical cord constriction may be identified and observed by ultrasound, if requested.

Some maternal factors are associated with stillbirth, including being age 35 or older, having diabetes, having a history of addiction to illegal drugs, being overweight or obese, and smoking cigarettes in the three months before getting pregnant.

## Prevalence

Stillbirths can happen to any mother no matter age, race, ethnicity, or religion. The highest rates of stillbirths happen in women who:

* are low socioeconomic status
* are 35 years or older
* have chronic medical conditions such as diabetes, high blood pressure, high cholesterol, etc.
* are African American
* have previously lost a child during pregnancy
* have more than one child at a time (twins, triplets, etc.)

Although these groups have higher prevalence of stillbirths, it does not mean that women who belong to these groups have a higher chance of a stillbirth occurring.

## Treatment

Fetal death *in utero* does not present an immediate health risk to the woman, and labour will usually begin spontaneously after two weeks, so the woman may choose to wait and bear the fetal remains vaginally. After two weeks, the woman is at risk of developing blood clotting problems, and labor induction is recommended at this point. In many cases, the woman will find the idea of carrying the dead fetus traumatizing and will elect to have labor induced. Caesarean birth is not recommended unless complications develop during vaginal birth. How the diagnosis of stillbirth is communicated by healthcare workers may have a long-lasting and deep impact on parents. Women need to heal physically after a stillbirth just as they do emotionally. In Ireland women are offered a 'cuddle cot', a cooled cot which allows them to spend a number of days with the child before burial or cremation.

## Epidemiology

The average stillbirth rate in the United States is approximately 1 in 160 births, which is roughly 26,000 stillbirths each year. In Australia, England, Wales, and Northern Ireland, the rate is approximately 1 in every 200 births; in Scotland, 1 in 167. Rates of stillbirth in the United States have decreased by about 2/3 since the 1950s.

The vast majority of stillbirths worldwide (98%) happen in low and middle-income countries, where medical care can be of low quality or unavailable. Reliable estimates calculate that yearly about 2.6 million stillbirths occur worldwide during the third trimester. Stillbirths were previously not included in the Global Burden of Disease Study that records worldwide deaths from various causes until 2015.