Safety index PK of 8 contraceptive methods

　　●external contraceptive pills

　　·Advantages: No side effects, easy to use.

　　·Disadvantages: Difficult to purchase, needs to be used every time, high failure rate.

　　·Failure rate: The unintended pregnancy rate within one year of using this method is 6 to 20%.

　　●in vitro ejaculation

　　·Advantages: Economical, convenient, and free of charge.

　　·Disadvantages: It requires a lot of self-control, which is very difficult for most people to do. and male The secretions that flow out during excitement contain a small amount of sperm , but only one sperm is enough for conception.

　　·Failure rate: The unintended pregnancy rate within one year of using this method is 20%.

　　●safe period

　　·Advantages: economical, safe, no side effects.

　　·Disadvantages: Three days before ovulation to two days after ovulation are the dangerous period, and other days are safe periods. However, the calculation of the safe period is based on the rules of the menstrual cycle. female Easier (see calculation of ovulation day)； People with irregular cycles are not suitable for this method.

　　·Failure rate: The unintended pregnancy rate within one year of using this method is 20%.