Stillbirth can result from a variety of issues affecting the fetus, the placenta, or the mother, and in many cases the exact cause remains unclear. Here’s a concise overview of common causes and contributing factors, along with notes on what is typically investigated. Direct causes and contributors
- Placental problems: Insufficient blood flow or other placental dysfunction can deprive the fetus of oxygen and nutrients, leading to stillbirth. This is one of the most frequent categories, especially later in pregnancy.
- Fetal genetic problems and congenital anomalies: Chromosomal abnormalities or major birth defects can make survival impossible even in utero. Some conditions are detectable before birth, while others are not.
- Umbilical cord problems: Knots, compression, or twists can cut off oxygen and nutrients to the fetus, potentially causing stillbirth, particularly near term or during labor.
- High blood pressure-related conditions: Chronic hypertension or pregnancy-related conditions like preeclampsia and placental abruption are linked to higher stillbirth risk.
- Infections: Maternal, fetal, or placental infections can lead to fetal distress and demise, especially in mid-to-late pregnancy.
- Growth problems: Fetal growth restriction (inadequate growth inside the uterus) is a common associated factor with stillbirth.
Other contributing factors and context
- Medical conditions in the mother: Diabetes, obesity, kidney or heart disease, autoimmune conditions, and substance use can increase stillbirth risk, often by affecting placental function or fetal development.
- Pregnancy complications: Preterm labor, multiple gestation (twins, triplets), and advanced maternal age can elevate risk in some scenarios.
- In many cases, no single cause is identified. Autopsy, placental exam, and fetal testing (when possible) are commonly used to try to determine a cause after a stillbirth. Information about autopsy procedures and hospital policies can vary.
What to know about uncertainty and prevention
- Even with thorough evaluation, the cause remains unknown in a substantial portion of stillbirths (estimates vary, often around one-third). This can be emotionally challenging and underscores the importance of support and counseling.
- Some risk factors are modifiable through good prenatal care and health management, such as controlling chronic conditions, managing blood pressure, avoiding smoking or illicit drugs, and seeking timely care for infections or unusual fetal movement or symptoms. Regular prenatal checkups help monitor fetal growth and placental health.
If you or someone you know is seeking information for a specific case, it’s important to discuss with a healthcare provider who can review medical history, pregnancy course, and available tests to identify potential contributing factors and plan support for future pregnancies.
