About

Throughout history, various cultures have developed folklore and methods to guess the sex of an unborn child before modern ultrasound technology existed. This tool utilizes a popular method from Eastern European and Asian folklore that correlates the parents' blood groups (ABO) and Rhesus (Rh) factors to the potential gender of the baby.

While genetics determines sex via X and Y chromosomes from the father, these traditional "blood type compatibility" charts suggest that certain combinations of parental blood types create environments more favorable to one gender. Disclaimer: This tool is strictly for entertainment purposes. It relies on anecdotal traditions, not medical science, and should not be used for family planning or medical decisions.

Formulas

This tool does not use a mathematical formula but rather a logic matrix based on folklore traditions. The generalized logic follows this structure:

Result = {

Boy if Mother = Father (Weak)Girl if Mother ≠ Father (Strong)Mixed depending on Rh

Reference Data

Mother's Type	Father's Type	Folklore Prediction	Bias
A	A	Girl	Strong Female Bias
B	B	Boy	Strong Male Bias
O	O	Girl	Historical Data
AB	AB	Boy	Rare Combo
A	O	Boy	Male Dominant
O	A	Girl	Female Dominant
Rh+	Rh+	Neutral	Equal Chance
Rh-	Rh+	Boy	Variable

Frequently Asked Questions

No. The biological sex of a baby is determined by the sperm cell (X or Y chromosome) at the moment of conception. Blood type does not scientifically influence this outcome. This tool is for fun and entertainment only.

The theory suggests that different blood types create different pH levels or chemical balances in the body, which might favor either X-sperm (female) or Y-sperm (male). While interesting, this has not been proven by modern embryology.

Yes, Rh incompatibility (e.g., Mother Rh- and Baby Rh+) is a real medical concern called Rh disease, but it relates to the health of the baby and antibodies, not the gender.

Since this is based on folklore rather than a universal scientific law, different regions (e.g., Chinese Chart vs. European Blood Method) have different rule sets and lookup tables.