Unexplained infertility is a common term used in the medical world when no reasons are identified for a couple not being able to conceive pregnancy. Unexplained infertility is also known as idiopathic infertility. It is estimated that up to 26 percent of infertile couples have unexplained infertility, however, the most common figures are 10 to 20 percent. 

Reasons for Unexplained Infertility: There are different possible reasons for unexplained infertility, but all of them cannot be ascertained. This is because of limited use of laparoscopic surgery, as a result of which not all causes of infertility can be detected. There are more than hundreds of biochemical reaction that take place before successful pregnancy, and a problem with any one of them may lead to difficulty in conception. Even the standards test for fertility look for obvious problems in men and women, and do not touch upon at the molecular level. 

Standard Tests for Unexplained Infertility: Fertility testing is a lengthy procedure and it is important for both the partners to go and consult a doctor. The physician who will carry out a basic assessment to check for reasons behind infertility and some of these tests include:

1. Semen Analysis: It detects sperm count of the male partner. In addition, sperm movement, mobility and structure are also analyzed. 
2. Blood Tests: For women, doctors tend to examine for ovulation, which can be detected and monitored through blood tests that check hormone. An ultrasound of the ovaries or an ovulation test using home test kit may also be conducted.  
3. Hysterosalpingogram: Ovulating women with unexplained infertility are most often prescribed a hysterosalpingogram that confims any blockage in the Fallopian tubes. During this procedure, a radiographic dye solution is placed in the uterine cavity. If the Fallopian tube remains open, dye moves through the tubes and appear in the abdominal cavity. If the Fallopian tubes are blocked, the dye is retained in the uterus or fallopian tubes or wherever blocked. 
4. USG: This is also used to examine the female reproductive organs and helps reveal any structural abnormalities. 

Treatment for Unexplained Infertility: Treatment for unexplained infertility are called “empirical” as they do not target a specific cause or a reason for unexplained infertility.

• Clomid treatment Drugs like clomid are known to improve fertility rates when the treatment is prescribed for at least 3 to 6 months. However, clomid treatment is unlikely to provide any benefits to women suffering from unexplained infertility, who already have regular periods and produce a healthy egg each month. Clomid treatment may sometimes be conducted in combination with AI or IUI.
• FSH plus IUI treatment Follicle stimulation hormone (FSH) plays an important role in reproductive system as follicles. It triggers the production of two hormones called estrogen and progesterone that help regulate and maintain menstrual cycles. Studies have shown improved pregnancy success rates with injectable FSH combined with IUI treatment, as compared to no treatment.
• Artificial insemination (AI) or intrauterine insemination (IUI) This fertility treatment involves insemination of sperm inside uterus for fertilization. Studies show that insemination with drugs, known as superovulation with IUI, helps trigger multiple eggs to ovulate, thus providing higher success rate than doing IUI without drugs.
• In Vitro Fertilization This process involves stimulating multiple follicles to release mature eggs that are eventually retrieved and fused with the sperms under laboratory condition. The embryo is then transferred into the womb of the mother at the end of 3 day or 5 days after fertilization. The remaining growth takes place naturally inside the womb of the mother.

IVF Success Rates: Women with normal egg reserve in the ovaries and unexplained infertility can opt for IVF as this technique has the highest success rate. Typically, couples aged below 40 are advised to undergo AI for three times before option for IVF as it is the last treatment resort. IVF not only helps couples conceive child, but also helps reveal the cause of unexplained infertility, The step-by-step monitoring of the developing embryo helps reveal the actual issue behind unexplained infertility.