Some stillbirth risks and causes come to light

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Globally, three to four million pregnancies end in stillbirth, which is defined as a fetus that dies during or after the 20th week of gestation. Yet despite the devastating consequences, the causes have long been unclear. Now, two separate studies have uncovered more about these causes as well as the risk factors for stillbirth and the good news is that some of them are avoidable.

In the first study, published in the Journal of the American Medical Association, a diverse group of 500 women agreed to autopsies and genetic testing of their stillborn fetuses, an examination of the placentas, an analysis of their medical records, and an interview. Based on this information, researchers were able to determine the cause of death in over 60 percent of the cases of stillbirth. The most typical causes of stillbirth were placental abnormalities, such as blood clots, which were responsible for almost a quarter of the cases. Fetal genetic abnormalities and major birth defects of the brain or heart comprised about 14 percent of the stillbirths, bacterial or viral infections caused 13 percent, umbilical cord abnormalities made up over 10 percent, and hypertension in the mother was implicated in over 9 percent of the cases. Other maternal medical conditions, such as diabetes, lupus, and thyroid disease, appeared to contribute to 8 percent of stillbirths.

The second study, published in the same medical journal, analyzed risk factors for stillbirth that can be identified before a woman becomes pregnant. Earlier stillbirths and miscarriages, as well as having no other children, significantly increased the risk. Other factors associated with a greater risk included having an AB blood type, smoking in the three months before pregnancy, being overweight or obese, and having a history of drug addiction. The researchers also discovered that diabetic women had 2.5 times the risk of a stillbirth, and that a pregnancy at age 40 or older meant 2.4 times the risk of women ages 20 to 34.

Clearly, a number of these risk factors can be modified or even eliminated. The study authors note that the rate of stillbirths has remained steady in the past 30 years. Perhaps, ACSH's Dr. Gilbert Ross observes, a better sense of the risks and causes will help lower the number of pregnancies that end in this unfortunate way.