Stillbirth Risk Calculator

Understanding Stillbirth Risk Factors

Stillbirth refers to the loss of a baby occurring at or after 20 weeks of gestation or during labor and delivery (losses prior to 20 weeks are classified as miscarriages). According to data from the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH), stillbirth affects approximately 1 in 170 pregnancies in the United States.

While many stillbirths occur without clear warning, identifying recognized demographic, clinical, and lifestyle risk factors helps healthcare teams implement individualized surveillance and preventive strategies.

Primary Epidemiological Risk Factors

• Maternal Age: Advanced maternal age (\(\ge 35\) and especially \(\ge 40\) years) is associated with higher rates of vascular and chromosomal complications.
• Pre-pregnancy BMI: Higher maternal body mass index (obesity class I and above) increases risks linked to placental insufficiency and metabolic dysregulation.
• Obstetric History: A history of previous intrauterine fetal demise or severe fetal growth restriction substantially increases recurrent risk.
• Chronic Medical Conditions: Pre-existing or poorly managed gestational diabetes, chronic hypertension, and autoimmune thrombophilic conditions (such as systemic lupus erythematosus or antiphospholipid syndrome).
• Substance Exposure: Smoking, tobacco use, and alcohol intake reduce placental blood flow and oxygen delivery to the fetus.

Evidence-Based Risk Reduction Measures

Many modifiable risk factors can be mitigated through proactive prenatal care:

• Maintain consistent prenatal visits and routine blood pressure and glucose screenings.
• Complete smoking and alcohol cessation prior to conception or as early in pregnancy as possible.
• Monitor fetal kick counts and movements starting around 28 weeks of gestation, immediately reporting decreased fetal movement to obstetric care providers.
• Follow recommended medical management for chronic conditions like hypertension and diabetes.

Expand your calculations with our VTE Risk Score in Pregnancy Calculator, Diabetes Risk Calculator, and Relative Risk Calculator.