Intra-uterine insemination (IUI) is a procedure where male partner’s semen is collected first. That semen sample has to be processed because raw semen has prostaglandins and they can cause severe uterine cramping and contractions and cannot be used for IUI. By washing the semen sample, seminal plasma and prostaglandins are removed and sperm can then be used for IUI.
Washed sperm is placed inside an insemination catheter and that catheter then passes through cervical canal and enters into uterine cavity and sperm is deposited inside the uterine cavity.
IUI can be used when males have retrograde ejaculation, hypospadias, or someone with reduced sperm quality. In females, IUI can be used in someone with cervical factor infertility, such as patients with chronic cervicitis, severely anteverted uterus, or retroverted uterus, or patients with poor cervical mucus or someone who had surgery. All these cervical problems can prevent sperm entry into the uterus. IUI can help sperm bypass the cervical obstruction and enter the uterine cavity, and then migrate to the fallopian tubes. IUI can also be used in couples with unexplained infertility.
The success rate of IUI varies widely among different studies. But generally speaking, IUI pregnancy rate depends on age of the patient (age <40, 10-15% per cycle, age >40, 5-10%), sperm quality (Kruger morphology>4% had 15-20% pregnancy rate, Kruger morphology <4% had 5-10% pregnancy rate), number of mature follicles, total motile sperm count after washing. Typically 3-4 cycles of IUI can be performed and if she is still not pregnant, she will need to consider IVF.
IUI must be timed with ovulation and ovulation can take place spontaneously after LH surge or can be induced with trigger shot. If one receives the trigger shot, IUI is typically performed within 12-24 hours. If she detects a spontaneous LH sure, IUI is typically performed the next day.
Typically 1 million motile sperm was considered the minimum amount of sperm needed for an adequate IUI. Males with much lower sperm count would need IVF procedure.