Many of you who are new to assisted reproductive technology are not sure between the concepts of artificial insemination and IVF. Even if they know the difference in general, they do not know when to choose which method to use for assisted reproduction treatment. First, let’s clarify the concept of both: 1. Artificial insemination (AI): is an assisted reproductive technology that uses non-coital delivery of sperm into the female reproductive tract for the purpose of conceiving a woman. According to the source of sperm, AI can be divided into artificial insemination by husband sperm (AIH) and artificial insemination by donor sperm (AID) from third party sperm. IUI is routinely used in our center. 2. In vitro fertilization and embryo transfer (IVF-ET) is often called “in vitro fertilization”. It is a technique in which eggs and sperm are removed from the human body and fertilized outside the body, developed into embryos, and then transferred back into the mother’s uterus for the purpose of conception. Unlike IUI, this technique usually includes the following steps: controlled ovulation, egg retrieval, in vitro fertilization and embryo transfer. The egg retrieval and transfer process need to be performed in an operating room, and the eggs need to be fertilized in an embryo culture room to form embryos for further culture, which requires high hardware and technical requirements of the fertility center. Now that we have clarified the concept of both, let’s talk about how to choose the right assisted reproductive technology for you. We usually refer to these conditions as indications for a particular treatment method. The indications for IUI (intrauterine insemination) are as follows: (1) Mild to moderate male sperm or semen abnormalities, such as various kinds of oligo- and malformed spermatozoa, long liquefaction time or non-liquefaction of semen; sperm density ≥ 15 million/ml, ≥ 15% of forward-moving sperm (a+b); conditions that can be IUI after semen treatment: ≥ 70% of class a sperm after upstream, ≥ 20 sperm/HPF (2) sexual dysfunction of the male partner, who can ejaculate semen out of the body but has difficulty in ejaculation during intercourse; (3) ovulation disorder; (4) unexplained infertility; (5) endometriosis (mild to moderate); (6) cervical infertility. The indications for IVF are as follows: (1) gamete transport disorders caused by various factors in the female partner, i.e., bilateral tubal obstruction or removal; (2) ovulation disorders; (3) endometriosis (moderate to severe); (4) oligospermia or hypospermia in the male partner; (5) unexplained infertility; (6) immunological infertility. As you can see, there is a certain degree of overlap between the indications for both. In our center, if the male partner’s semen routine meets the above criteria for IUI and the female partner has at least one side of the fallopian tube open, it is recommended to use IUI to help conceive first according to the individual’s wish, and if IUI fails three times, it is generally recommended to choose IVF instead. Of course, the final decision on which method of fertility should be used requires an assessment of each patient’s specific situation by a doctor at a specialized fertility center.