The ancient Chinese birth chart compares the month of conception and the mother's age at conception to predict whether she is having a boy or a girl. While the accuracy of the chart is unknown, legend says that it was discovered in China 700 years ago, according to Parents Magazine.
Some couples who desire a particular gender of child use the Chinese birth chart as a guide to the best timing for conception, says BabyMed; however, this method is not medically verified and is based in folklore.
The Chinese birth predictor is said to be predicated on the Chinese beliefs in the Five Elements and yin and yang, claims About.com. It refers to a lunar calendar, so it requires the use of a converter to change Western calendar months to lunar calendar months.