Pregnant tired of greasy boy verification

Do not advocate gender identification: There are maternal DNA blood tests: Genetic engineering technology can be used to take maternal venous blood to determine the sex of the fetus. There is no risk to the fetus and the mother. The accuracy of the current identification can reach 99%. Sex inference is made through chromosomes, especially for male babies. The reaction is strongly positive. The baby is examined after 8 weeks, and the result is obtained in about 2 days. B-ultrasound identification of fetal sex requires more than 19 weeks of pregnancy, but even the most experienced imaging experts can only determine the sex of the baby at three and a half months or more of pregnancy, and the accuracy rate cannot reach 100%, but the safety is the highest.