Odds Of Having Twins Calculator

Odds of Having Twins

Maternal Age

Please enter a valid age (15-55).

Age of the mother at conception.

Family History of Twins?Twins in the family (especially mother's side).

Previous Twin Pregnancies?Number of prior twin births.

EthnicitySome ethnicities have higher twinning rates.

Estimated Probability

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How It's Calculated

The baseline probability (1.1%) is adjusted by factors: maternal age (+0.5% per year after 30), family history (+0.5% for mother side, +1% for both), previous twins (+1% per twin), and ethnicity (African +0.3%, Caucasian +0%, Hispanic +0.1%, Asian -0.3%). The final result is capped at 20%.