1. Do I need contraception during breastfeeding? Ovulation has occurred before the return of menstruation after childbirth. If you have unprotected sex when you ovulate for the first time after childbirth, you may become pregnant before you resume menstruation, so you must use contraception during breastfeeding. 2.When does contraception during breastfeeding start? From the first sexual intercourse after childbirth, we must insist on contraception. 3.What are the methods of contraception after childbirth? To ensure the safety of mother and child, use long-acting, efficient, reversible and safe contraceptive methods. (1) intrauterine device: simple, safe, regardless of age, can be effective contraception 5 to 15 years. It can be placed within 48h and more than 6 weeks after flat birth; it can be placed during cesarean section or after 6 months, but it is not suitable for puerperal infection. (2) Subcutaneous implant: effective contraception for 3-5 years. It can be implanted after 6 weeks postpartum for lactating women to exclude pregnancy and after birth for non-lactating women. (3) Condoms: the failure rate of conventional use is high, and they need to be used correctly throughout each sexual intercourse in order to guarantee effective contraception. Contraceptive injection and vasectomy are not routinely recommended 4, what are the hazards of unwanted pregnancy during breastfeeding? (1) The reduction of breast milk secretion will affect the nutrition of the child being raised, and the high level of sex hormones in the breast milk will have a potential risk to the future health of the child after breastfeeding. (2) Abortion during breastfeeding, especially after cesarean section, has high surgical risks and may lead to incisional pregnancy, which can be life-threatening in serious cases. (3) Pregnancy during breastfeeding can lead to increased adverse pregnancy outcomes such as intrauterine growth retardation, miscarriage and preterm delivery.