Stillbirth refers to the delivery of a fetus that shows no signs of life—such as breathing, heartbeat, umbilical cord pulsation, or voluntary muscle movement—at or beyond 20 weeks of gestation or with a fetal weight of at least 350g. Fetal death that occurs during labor is also classified as stillbirth. However, cases where labor induction occurs due to severe fetal structural abnormalities or non-viable preterm rupture of membranes are not included within the definition of stillbirth.
Etiology
Placental and Umbilical Cord Factors
Hypoxia caused by significant placental hemorrhage or umbilical cord abnormalities is a common cause. Placental factors include placenta previa, placental abruption, vasa previa, acute chorioamnionitis, chorioangioma, and choriocarcinoma; umbilical cord factors include umbilical cord knots and cord prolapse.
Fetal Factors
Severe structural abnormalities, fetal growth restriction, complications specific to twin pregnancies, fetal infections, severe hereditary diseases, and maternal-fetal blood group incompatibility are examples of fetal-related causes.
Maternal Factors
Maternal complications and pregnancy-related disorders, such as antiphospholipid syndrome, intrahepatic cholestasis of pregnancy, diabetes, cardiovascular diseases, or shock of various etiologies, may contribute to stillbirth. Uterine issues, such as excessive uterine tension, overly strong contractions, uterine anomalies, or uterine rupture, can lead to local ischemia that affects the placenta and fetus.
Unexplained Causes
In some cases, the cause of stillbirth cannot be determined.
Clinical Presentation and Diagnosis
Symptoms include maternal perception of absent fetal movements and cessation of abdominal growth. Clinical examinations reveal an absence of fetal heart tones and uterine size inconsistent with gestational age. Ultrasound examination confirms the diagnosis. Approximately 80% of fetal deaths result in spontaneous delivery within 2 to 3 weeks. Prolonged retention of a stillbirth in the uterus may lead to maternal coagulation dysfunction. If the fetus remains undelivered for more than 3 weeks, degenerating placental tissue releases thromboplastin into the maternal bloodstream, activating intravascular coagulation factors and potentially leading to disseminated intravascular coagulation (DIC). Retention of the fetus for more than 4 weeks further increases the risk of DIC and may result in severe hemorrhage during delivery.
Management
Once a stillbirth is confirmed, it is essential to obtain a detailed medical history, including family history, past medical history, and information about the current pregnancy. Possible causes should be actively investigated, and labor induction should be initiated as early as possible. Autopsy of the fetus is advised to document any abnormal structural features, along with macroscopic and histopathological examination of the placenta, umbilical cord, and membranes. Genetic testing of the stillbirth and, if needed, the placenta is recommended to identify potential underlying causes whenever feasible. Postpartum counseling and psychological support should also be provided.
Several methods exist for labor induction, such as misoprostol use, intra-amniotic injection of ethacridine, and oxytocin administration. The selection of the method should depend on gestational age, the presence of uterine scars, and the preferences of the mother after informed consent. For women with a history of uterine surgery before 28 weeks of gestation, an individualized induction plan is necessary. For pregnancies beyond 28 weeks, induction should follow obstetric guidelines, with vaginal delivery as the preferred mode of delivery; cesarean section should be reserved for special circumstances.
When a singleton stillbirth remains undelivered for over 4 weeks, coagulation function should be assessed. Abnormalities in coagulation parameters should be corrected to restore effective levels of fibrinogen and platelets before inducing labor. Fresh blood should be prepared, and postpartum hemorrhage and infection should be carefully monitored and managed.
Future Pregnancy Considerations
Women with a history of stillbirth have a risk of experiencing stillbirth approximately 2.5 times greater than that in normal pregnancies. Despite thorough and systematic evaluations, at least one-quarter of stillbirth cases may remain unexplained. High-risk pregnancies complicated by comorbidities are associated with a significantly increased likelihood of recurrent stillbirth. For subsequent pregnancies, individualized prenatal management plans are essential to reduce the risk of stillbirth recurrence.