After the sperm is ejected from the male penis into the female body, it usually survives for 3-10 days. During this time, the sperm pass through the uterus into the fallopian tubes and unite with the egg in the abdominal region of the fallopian tube to form a fertilized egg. If the egg is not encountered during this time, the sperm will remain inside the fallopian tube for a period of time until it loses its internal activity and is expelled with the woman’s metabolic cycle. The environment inside the woman’s vagina also determines the length of time that sperm will remain alive. A vagina with too much acidity will have a relatively short survival time, while a vagina with the right pH level will have a longer survival time for sperm. If a man is in good health, his sperm survival rate is relatively high and his survival time will be extended. It is recommended that women who want to prepare for pregnancy should not wash their vagina for a short time after the sperm has entered it to avoid affecting the survival time of the sperm.