Twins can be conceived through natural conception, in vitro fertilization, and taking ovulation stimulation drugs, but only women with infertility or ovulation disorders can use the latter two methods. 1. Natural conception: People with a family history of multiple births are usually prone to conceive twins or multiple births. 2. In vitro fertilization (IVF): For various causes of infertility, in vitro fertilization can be accomplished through assisted reproductive technology. Generally, in order to increase the success rate of IVF, multiple embryos will be transferred to the uterine cavity of the pregnant woman to complete the implantation. As long as the transferred embryos are able to survive, the probability of conceiving twin or multiple babies is high. 3. Taking ovulation-promoting drugs: This method is mostly used for women suffering from ovulation disorders such as polycystic ovary syndrome, etc. Drugs such as clomiphene citrate capsules and human chorionic gonadotropin can be used according to the doctor’s prescription, which can promote follicle development and discharge and increase the number of eggs, thus improving the probability of conceiving twins or multiple births. Because of the higher risk of spontaneous abortion, preterm labor, and maternal complications with twins, it is not recommended for normal women to use drugs or surgery to make themselves pregnant with twins.