If you wear a double-layer condom the whole time compared to an IUD, wearing a double-layer condom the whole time is safer than an IUD. If you wear a double-layer condom, but not the whole time, or if you wear a single-layer condom the whole time compared to an IUD, an IUD may be safer. This is because single-layer condoms are prone to breakage, and when they do, they increase the probability of failure and can easily lead to pregnancy. If the condom is not worn throughout the entire process, there is a small amount of sperm in the early prostatic fluid, and the small amount of sperm may enter the uterine cavity and combine with the egg to cause contraceptive failure. The IUD has a higher safety factor, but there are also pregnancies after the IUD, called pregnancy with an IUD, which is also very common in the clinic. In our daily life, we prefer to use a double-layer condom to reduce the probability of contraceptive failure and to reduce the occurrence of gynecological diseases in women.