If a man and a woman live together, the following conditions must be present if they become pregnant: First, the male partner’s semen is normal, the sperm’s vitality is normal, and the liquefaction time is normal. Secondly, the female partner must have normal ovulation. Third, there is no immune infertility. Fourth, the fallopian tubes are open and the peristalsis of the fallopian tubes is normal to transport sperm or fertilized eggs. Fifth, the endometrium needs to reach 0.9 cm or more at the time of ovulation in order to allow the fertilized egg to implant. Sixth, the thyroid function is normal. Seventh, there must be a normal sexual life and no contraception in order to get pregnant. Eighth, there is no systemic disease.