Fallopian tubes are functionally and anatomically important organs for successful pregnancy. They play vital role in the transport of gametes and embryos, and are sites of sperm preparation, fertilization, and embryo development. Hysterosalpingography assesses the tubal patency, but not the tubal function. In case of unexplained infertility, a likely tubal cause of infertility is tubal dysfunction, including an oocyte capture disorder in the fimbriae during ovulation and the inability to transport gametes and embryos.
Treatment strategies for patients with tubal dysfunction include endoscopic surgery, including laparoscopy and salpingoscopy, superovulation with gonadotropins and IUI, as well as in vitro fertilization (IVF). In younger patients with unexplained infertility who desire spontaneous pregnancy, endoscopic surgery is one of the main options for diagnosing intratubal and peritubal conditions and treating of tubal dysfunction. If patients want to avoid endoscopic surgery or cannot become pregnant after such a surgery, IVF is the ultimate infertility procedure. Patients with unexplained infertility who have reduced ovarian reserve, or have a late reproductive age, should receive IVF as a first-line treatment.
Here we briefly review the treatment strategies for tubal dysfunction with unexplained infertility.
Laparoscopic surgery for patients with unexplained infertility can contribute to a successful outcome of pregnancy if mild endometriosis or peritubal adhesion is detected and treated. After laparoscopy, most women conceived spontaneously. However, after IVF, cumulative pregnancy rates are relatively higher at 1 year after treatment. Therefore, in younger patients with unexplained infertility who desire spontaneous pregnancy, laparoscopic surgery is one of the main treatment options.
Superovulation with Gonadotropins and IUI
In patients with unexplained infertility, the cumulative pregnancy rate after timed sexual intercourse or IUI or mild ovarian stimulation is 10-20%, which is comparable to survival. However, the combined treatment of superovulation with gonadotropins and IUI gives cumulative pregnancy rates of 50-60%. A large number of injected sperm and ovulated eggs can overcome mild tubal dysfunction or endometriosis.
The frequency of ovarian hyperstimulation syndrome is rarely low, but after these treatments, multiple pregnancies occur with a high frequency of 6-35%. Therefore, patients should be informed about the risk of multiple conceptions before undergoing ovarian stimulation.
In Vitro Fertilization (IVF)
If patients with unexplained infertility want to avoid endoscopic surgery or cannot become pregnant after such a surgery, IVF is the final treatment. Suggestions recommend IVF if the duration of infertility is ≥2 years. The probability of giving birth during the first IVF cycle is 20.9 times higher than in subfertile couples with tubular patency in a randomized controlled trial. IVF should be the first-line treatment for women with unexplained infertility who are aged >40 years due to low efficacy and poor pregnancy outcomes of ovulation induction and IUI, with advance ovarian aging.
In conclusion, evaluations of the fallopian tubes and peritubal environment with laparoscopy and salpingoscopy are key for patients with unexplained infertility who desire spontaneous pregnancy. In addition, endoscopic surgery may benefit some infertile patients with mild tubal dysfunction and mild endometriosis. Patients with reduced ovarian reserves and late reproductive age should proceed directly to IVF.