Causes of Stillbirth

Losing a baby in the womb stage or during birth is a major life incident which can bring immense grief to the parents and family. Not knowing the cause of stillbirth can add to the grief and confusion of the bereaved parents.

According to the American Pregnancy Association, one pregnancy out of a hundred and sixty pregnancies ends in stillbirth. Unbelievably, the causes of 25% of stillbirth cases remain unknown. Of the known causes, here are the most common reasons why stillbirths occur:

Complications of the placenta are one of the most common causes of stillbirths. Placenta is an organ which develops during pregnancy inside the uterus. On its one end, it is attached to the inner uterine lining and its other end connects to the umbilical cord of the growing fetus. Placenta facilitates the supply of oxygen and nutrients from the mother's blood circulation to the fetus, thus it is a vital lifeline to the survival of the fetus.

Any abnormalities in the placenta carry a risk of fetal death. Placental abruption is the cause in most stillbirth cases. Placental abruption is the dissociation of the placenta from the growing baby during pregnancy. This cuts off the supply of oxygen and nutrients to the baby leading to stillbirth.

What causes placental abruption is not clearly known. Physical injury to the abdomen and certain pregnancy complications such as HELLP syndrome can cause placental abruption.

Preeclampsia is a serious complication during pregnancy which can affect approximately 5-8% of pregnant women. It can begin with high blood pressure and proceed to become more severe that it can be life-threatening in some cases. Complications that arise due to preeclampsia and can cause stillbirth include:

·         Intrauterine growth restriction: When the blood supply to the placenta is restricted in preeclampsia, it directly results in decreased nutrition and oxygen supply to the fetus, thus restricting the normal development of the baby, which is one of the causes of stillbirth.

·         HELLP syndrome: Preeclampsia can lead to another serious condition called the HELLP syndrome. HELLP is an abbreviation of the triad signs that are characteristic of the condition, namely, Hemolysis, ELevated liver enzymes, Low Platelet count. Major complications of HELLP syndrome which can lead to stillbirth are placental abruption, blood clotting disorder leading to bleeding problems, accumulation of fluid in lungs, abdomen or brain and liver injury, damage or rupture.

10% of stillbirths are caused by an infection the mother contracts before or during pregnancy.

Bacteria that normally live in the vagina such as, E.coli and group B streptococcus are not harmful as long as they remain in the vagina. But, when they move to other parts of the body through the cervix, they cause infection in the migrated area. When these bacteria enter the uterus during pregnancy, they may infect the amniotic membranes, amniotic fluid and the placenta, a condition called intrauterine infection.

Other routes of infection may be through the placenta or fallopian tubes.

Intrauterine infection carries a high risk of rupturing the amniotic membranes prematurely leading to preterm labor or stillbirth.

Other infections include Lyme disease, cytomegalovirus, Group B Strep, Herpes Simplex etc.

The umbilical cord which connects the baby to the mother during pregnancy can undergo complications such as:

·         Cord Prolapse:  The umbilical cord may drop down through the cervix before the baby during birth, resulting in compression and loss of oxygen supply to the baby.

·         Nuchal Cord: During vaginal delivery, the umbilical cord may get wrapped around the baby’s neck, leading to fetal death.

Intrahepatic cholestasis of pregnancy (ICP) is a liver disorder which occurs in 1 in 1000 women only during pregnancy.

Under normal conditions, liver secretes an important fluid called the bile. Bile produced in the liver is transported to the gallbladder where it is stored until digestion of food in the stomach begins. From gallbladder, bile is released into the digestive tract where it digests fats in the food and aids in the absorption of fat breakdown in the small intestine.

In intrahepatic cholestatis of pregnancy, bile produced in the liver, for some unknown reason, doesn’t leave the liver. It gets accumulated in the liver and excess bile is spilt into the bloodstream. As a result, the normal functioning of the liver is disturbed, leading to high levels of bile acids in the blood.

If ICP is not treated during pregnancy, there is a risk of stillbirth due to premature labor, premature water breaking or release of meconium inside the womb resulting in choking and death.

Other causes of stillbirth include:

·         Premature labor

·         Chromosomal abnormalities      

·         Excessive loss of blood during delivery

·         Gestational diabetes

·         Pre-pregnancy health conditions like obesity and high blood pressure