1. What is Twins Test Probability?

Twins Test Probability estimates the likelihood of a twin pregnancy based on hCG levels compared to singleton pregnancy reference values. Higher hCG levels often indicate multiple gestation pregnancies.

2. How Does the Calculator Work?

The calculator uses the probability formula:

Where:

• \( hCG \) — Current hCG level (mIU/mL)
• \( Singleton \) — Reference hCG level for singleton pregnancy (mIU/mL)

Explanation: The algorithm compares your hCG level against twice the singleton reference value to estimate twin pregnancy probability.

3. Importance of hCG Testing

Details: Human Chorionic Gonadotropin (hCG) levels can provide early indications of multiple pregnancies, as twin pregnancies often produce significantly higher hCG levels than singleton pregnancies.

4. Using the Calculator

Tips: Enter your current hCG level and the reference singleton hCG value for the same gestational age. Both values must be in mIU/mL and greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is hCG for predicting twins?
A: While higher hCG levels can suggest twins, ultrasound confirmation is necessary for definitive diagnosis. hCG alone provides probability estimates.

Q2: What hCG levels indicate twins?
A: hCG levels that are approximately double the normal singleton values for the same gestational age may indicate twin pregnancy.

Q3: When is the best time to test for twins?
A: Between 6-8 weeks gestation, when hCG levels are typically at their peak and most indicative of pregnancy type.

Q4: Are there other factors that affect hCG levels?
A: Yes, gestational age, individual variation, molar pregnancy, and certain medical conditions can all affect hCG levels.

Q5: Should I rely solely on this calculator?
A: No, this calculator provides probability estimates only. Always consult with healthcare providers and undergo proper medical testing for accurate diagnosis.