Stillbirths in the US: Why Women Lose Their Babies
One in 160 pregnancies ends in stillbirth in the US every year, a statistic that exceeds that of any other developed country in the world. A new study identifies and reports on why so many women in the US lose their babies, with the hope that the information can help reduce stillbirths in the future.
Stillbirths in the US have remained steady since 2003
Each year in the United States, about 26,000 stillbirths (defined as the death of a fetus at 20 weeks’ gestation or later) occur, which is the same as the number of infant deaths. While the average rate of stillbirths is 6.2 per 1,000 births, among non-Hispanic black women the rate is 11.13 compared with 4.79 among non-Hispanic white women and 5.44 for Hispanic women. The reason for this wide disparity is unknown.
Regardless of the race of the pregnant woman and her fetus, the loss is often met with disbelief, sorrow, anger, and the question: Why did my baby die? This is the question tackled by The Stillbirth Collaborative Research Network Writing Group, which studied all stillbirths at 20 weeks or later in 59 tertiary care and community hospitals in five different areas.
Postmorten examinations were done on 512 neonates from 500 women, and the authors also conducted placental histopathology (study of the structure of the placenta), fetal karyotype (used to determine abnormalities), and other evaluations.
The investigators declared a probable cause of death in 312 stillbirths (60.9%) and a possible or probable cause in 390 (76.2%). The identified causes of stillbirth were as follows:
- Obstetric conditions (cervical insufficiency, preterm labor, preterm premature rupture of membranes, placental abruption), 150 (29.3%)
- Abnormalities of the placenta, 121 (23.6%)
- Fetal genetic/structural abnormalities, 70 (13.7%)
- Infections (involving the fetus, placenta, or severe maternal systemic infection), 66 (12.9%)
- Abnormalities of the umbilical cord (prolapse, strictures, thrombosis), 53 (10.4%)
- High blood pressure disorders (e.g., preeclampsia, chronic hypertension), 47 (9.2%)
- Other medical conditions affecting the mother (e.g., diabetes, antiphospholipid syndrome), 40 (7.8%)
When stillbirths among both non-Hispanic white women and Hispanic women were compared with those among non-Hispanic black women, the latter were nearly twice as likely to be associated with obstetric complications (43.5% vs 23.7%) and more than three times more likely to be associated with infections (25.2% vs 7.8%).
Identifying the causes of stillbirth will better allow experts to better determine how to bring the rate down. Robert M. Silver, MD, University of Utah School of Medicine, and one of the study’s authors, explained that “If we know exactly what caused the death in the first case, we can much better counsel them [women who have lost a child to stillbirth] and often we can do interventions that may improve the outcome in subsequent pregnancies.”
The authors concluded that their findings “support performing perinatal postmortem examination, placental histology, and karyotype in all cases of stillbirth,” since they were able to make a probable or possible identification of cause of stillbirth in the majority of cases. They noted that interventions developed to prevent stillbirths “should consider the observed differential distribution of causes of death as gestational age advances, as well as variation by race/ethnicity.”
Stillbirth Collaborative Research Network Writing Group. The Journal of the American Medical Association 2011; 306(22): 2459-68