Understanding Unexplained Infertility: Causes, Treatments

Grace Fertility

Authored & Verified by:

Dr. Reubina Singh

MS (OB/GYN), MBBS - Senior Infertility Specialist

What Is Unexplained Infertility?

Infertility is already a tough diagnosis to face, but when doctors label it as unexplained, it can feel even more frustrating. Unexplained infertility occurs when a couple has been trying to conceive for a year or more (or six months if over 35), and there is no clear reason why they haven’t been able to get pregnant. All tests appear normal, with regular periods, normal semen parameters, and healthy ovulation cycles.

This leaves many couples feeling lost and unsure of what steps to take next, especially since there’s no definitive answer. But don’t lose hope—unexplained infertility doesn’t mean you won’t ever conceive. It just means that finding a solution might take some extra time and testing.

Common Causes of Unexplained Infertility

While the exact causes of unexplained infertility remain unclear, there are several factors that might contribute to it:

Egg and Sperm Quality: Sometimes the issue is fertilization itself—egg and sperm may have trouble meeting or forming a viable embryo.
Environmental Factors: Conditions like endometriosis or other inflammatory diseases can create a toxic environment in the reproductive system, preventing pregnancy.
Inflammatory Responses: High inflammation throughout the body can affect the fallopian tubes and the overall fertility process, making conception more difficult.
Subtle Quality Issues: While tests may show normal semen parameters, there could still be issues with sperm or egg quality that are undetectable with standard tests. Advanced lab techniques, such as IVF, may help detect these issues.
Ovarian Reserve: Even if ovulation is occurring normally, there may be issues with the number or quality of eggs available, which might only be noticed with advanced fertility testing.

Treatments for Unexplained Infertility

If you’re diagnosed with unexplained infertility, it’s important to explore your treatment options. There are several strategies available to help increase your chances of conceiving, but not all of them are right for every couple.

1. Natural Conception with Timed Intercourse

For couples with unexplained infertility, the first step is often trying to conceive naturally, but timing intercourse around ovulation. While this method gives a low chance of success (only about 2-4% per cycle), it can work for some people. However, the longer the infertility persists, the less effective this option becomes.

2. Ovulation Induction Medications

If natural conception doesn’t work, medications like Clomid (clomiphene citrate) or Letrozole (Femara) are often prescribed to stimulate ovulation. These oral medications encourage the ovaries to release eggs, increasing the chances of conception. However, the success rate is still only around 2-4% per cycle.

3. Injectable Hormones (Gonadotropins)

For those who don’t respond to oral medications, injectable hormones like FSH (follicle-stimulating hormone) can be used to stimulate the ovaries to produce more eggs. While this treatment is more expensive and comes with a higher risk of multiple pregnancies (twins or even triplets), it’s still not a guaranteed solution. Success rates here range from 5-7% per cycle.

4. Intrauterine Insemination (IUI)

IUI involves placing processed sperm directly into the uterus at the time of ovulation. For unexplained infertility, this method is less likely to be effective, with only about a 5-10% chance of success per cycle. It’s generally not recommended to proceed with IUI without the support of other treatments, like ovulation induction.

5. Super Ovulation and IUI

Combining injectable hormones (gonadotropins) with IUI is called super ovulation. This method increases the chances of pregnancy by increasing the number of eggs released. Success rates for super ovulation with IUI are slightly better than standard IUI alone, but still relatively low, at about 10% per cycle.

6. In Vitro Fertilization (IVF)

When other treatments have not worked, IVF is often the most effective option for couples with unexplained infertility. IVF has a success rate of 25-45%, depending on age and specific fertility factors. During IVF, eggs are retrieved from the ovaries, fertilized in a lab, and the embryos are monitored before being transferred to the uterus.

IVF allows doctors to bypass many of the natural barriers to conception, such as sperm quality and fertilization issues, and gives the couple a much higher chance of success. It also provides the opportunity for genetic testing of embryos, which can further improve success rates.

Why IVF Is the Best Option for Unexplained Infertility

For couples with unexplained infertility, IVF is often the gold standard in treatment. While other treatments like IUI and ovulation induction can be helpful, they are often not as effective, particularly if the couple has been trying for a while with no success.

Studies have shown that IVF has a much higher chance of pregnancy compared to less invasive treatments. For example, one study found a success rate of 49% for women over 38 who went straight to IVF. This is far higher than the 5-10% success rate of IUI, even with ovulation medications. IVF allows doctors to control much of the fertility process, from egg retrieval to embryo transfer, improving the chances of a successful pregnancy.

Making the Decision: Should You Go Straight to IVF?

The decision to proceed with IVF is a personal one, but for many couples, it is the most effective way forward. While IVF is more expensive and requires more intervention, it often gives the best chance of achieving a healthy pregnancy. For those who are unsure, it’s important to discuss the risks, benefits, and costs with your fertility specialist. Understanding the process and the potential outcomes can help you make an informed decision that aligns with your family-building goals.

Conclusion

Unexplained infertility can feel like an incredibly frustrating challenge, but it’s important to remember that you are not alone. There are several treatments available, from medications and IUI to IVF, and while some may seem less effective, they could still play a part in your fertility journey.

If you’re struggling with unexplained infertility, educating yourself on the available treatments is key to making the right decisions for you and your partner. With the right approach and a bit of patience, many couples with unexplained infertility do go on to build the families they’ve dreamed of.