“Following the central government’s decision to launch the “separate” two-child policy, many families want to have a second child, and recently there has been a sharp increase in the number of couples visiting the hospital for consultation. According to the statistics of our pre-conception clinic, these women who want to have a second child are roughly 35 to 42 years old, the oldest one is 47 years old and her child is already in her 20s. The first thing to consider when having a second child is age. Generally speaking, the interval between two children is 4-5 years, and a couple over 35 years old is an advanced maternal age, and if the couple is older, the quality of both eggs and sperm decreases and the chances of problems with fertilized eggs increase. In addition, a woman’s body function decreases with age, and the chances of developing various complications during pregnancy, such as hyperemesis gravidarum, are high. Therefore, it is best to have a child under the age of 35, regardless of whether it is your first or second child. If you are older than that, you must go to the hospital for a comprehensive checkup before pregnancy. Many women choose to have a cesarean delivery for their first child, which has laid a hidden risk for having a second child. A uterus that has undergone a cesarean section is a scarred uterus, which increases the likelihood of placenta praevia, and most of them are fatal placenta praevia, which makes both the pregnant woman and the child prone to problems during pregnancy and delivery. The most undesired clinical condition is cesarean scar pregnancy, which is when the embryo grows on the scar left by the last cesarean delivery, accounting for 15.2% of cases, with the risk of causing uterine rupture and postpartum hemorrhage. Therefore, if the first child was delivered by cesarean section, the second child must have several more checkups, pay close attention to the condition of the uterus and fetus, and seek immediate medical attention in case of bleeding and abdominal pain. Also pay attention to the weight of the pregnant woman. As you get older, your body’s metabolism slows down and the calories you take in may not be consumed. Therefore, advanced maternal age is prone to gain weight and gestational diabetes, so it is best to visit a nutrition clinic to monitor your nutritional status. In addition to diet control, exercise is also a good way to control weight. If the weight control is ideal, the second delivery, even if it is natural, will be much smoother. The uterus and birth canal are like an elastic band, the first birth has been held open once, the second time is relatively easy to hold open.