What Is the Clomid Success Rate for Ovulation and Pregnancy?

When Clomid Works Best and When It Doesn't

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What is the Clomid success rate? If you're considering this popular fertility drug, you likely want to know if it'll work for you. For women with ovulatory problems, the success rates are pretty good. Between 70 and 80 percent of women taking Clomid will ovulate during their first treatment cycle.

Of course, ovulation is not the same as getting pregnant.

What Are the Chances Clomid Will Work in the First Month?

Depending on which research studies you reference, the odds of conceiving during any one Clomid treatment cycle are between seven and 30 percent.

The effectiveness of Clomid varies depending on the cause of infertility.

Keep in mind that those with no fertility problems have about a 25 percent chance of getting pregnant in any given month. If you don't get pregnant after one month, don't panic. Needing more than one cycle is common.

What Are the Odds of Getting Pregnant After Many Cycles on Clomid?

A literature review published in Human Reproduction considered several studies on Clomid. Altogether, the Clomid success rates for just over 5,000 women were included. In this study, they found that

  • 73 percent eventually ovulated on Clomid
  • 36 percent eventually achieved pregnancy
  • 29 percent gave birth

The birth rate is lower than the pregnancy rate due to miscarriages. Clomid doesn't seem to increase the risk of miscarriage.

Other studies have reported pregnancy success rates between 30 and 40 percent when using Clomid. Again, the live birth rate would be lower due to pregnancy losses.

However, Clomid success is also dependent on why you can't get pregnant. Clomiphene citrate can work well for those with ovulation problems. But what if ovulation isn't an issue?

Another study, this one from Scottland, looked at success rates for couples diagnosed with unexplained infertility. Couples were randomly assigned to one of three groups: "expectant management," treatment with just Clomid, or Clomid with IUI.

The most effective treatment group was the IUI plus Clomid group, who achieved a 22 percent live birth rate. The Clomid only treatment group did similarly to the couples who received no treatment at all.

What If You Don't Conceive After Six Months of Clomid?

If Clomid doesn't help you get pregnant after six months, your doctor should suggest you try something else. There are a few reasons for this.

One, if Clomid hasn’t helped you conceive after six months, the odds of it working on month seven or eight are very low. Remember that your fertility naturally declines with age. If something isn't working, it's best to move on.

Secondly, extended treatment with Clomid may lead to fertility problems of its own. Women who have gone through several Clomid cycles may have thinner endometrial linings, which can impede with embryo implantation. (This will correct itself after time away from Clomid and is not a long-term adverse effect.)

Lastly, some early research on Clomid found a possible increased cancer risk in women treated for more than six cycles. It’s unclear if this risk comes from Clomid or from infertility itself, but, to be on the safe side, you should not take Clomid for more than six cycles.

At What Dose Will Clomid Work for You?

Your doctor will likely start you on the lowest does first, which is 50 mg. If you don’t ovulate on 50 mg, your doctor may try one more cycle at the same dose, or increase your dosage by 50 mg.  

If you do ovulate, and you just don’t get pregnant, then your doctor will keep you at the dose you’re on. Increasing the dosage doesn’t increase your odds of getting pregnant. In fact, higher doses of Clomid may lead to side effects that reduce your fertility.

One possible side effect of Clomid is thickened cervical mucus. Cervical mucus is vital to fertility and helps the sperm survive the vaginal environment and make their way into the uterus and eventually to the egg.

Your doctor will want you on the lowest possible dosage, just enough to trigger ovulation, but not more than that.

When Is Clomid Not as Successful?

Clomid is not the magic fertility drug that some people mistake it to be. It works well in the right circumstances—but it can be completely unsuccessful in the wrong ones. If there are additional problems besides irregular or absent ovulation, or there are any male factor infertility issues that have not been addressed, success will be lower.

It's questionable how successful Clomid therapy is for couples diagnosed with unexplained infertility. Research has found that Clomid should be used along with IUI treatment in couples with unexplained infertility, for best results.

Also, Clomid does not always work well for women who are dealing with age-related infertility, with low estrogen levels, or women with primary ovarian insufficiency (formerly known as premature ovarian failure.) It may also not work in women whose ovulation problems are caused by a thyroid issue.

Women who are obese may have better success with Clomid if they lose weight. Whether or not you should take the time to lose weight before starting treatment depends on your age and how obese you are. Discuss the best course of action with your doctor.

What If I Don't Ovulate While Taking Clomid?

What if you don't even ovulate while taking Clomid? There are some things your doctor can try before suggesting other treatments.

For women with PCOS, the cancer drug letrozole (Femara) may be more successful at triggering ovulation than Clomid. Taking Clomid along with the diabetes drug metformin has also increased success rates for some women.

If Clomid does help you ovulate, but after six months of treatment you still have not gotten pregnant, the next step may be a referral to a fertility clinic (if you're not already being seen at one). Or, your doctor may suggest gonadotropins (injectable fertility drugs).

A Word From Verywell

Remember that while you may be primarily familiar with Clomid and perhaps IVF treatment, there are, in fact, many more fertility treatment options for you to consider. Always talk to your doctor if you’re concerned about the next step or if Clomid isn't working as you hoped it would.

Sources:

Arici, Aydin; Seli, Emre. “Ovulation induction with clomiphene citrate.” Uptodate.com.

Brandes M1, Hamilton CJ, van der Steen JO, de Bruin JP, Bots RS, Nelen WL, Kremer JA. “Unexplained Infertility: Overall Ongoing Pregnancy Rate and Mode of Conception.” Hum Reprod. 2011 Feb;26(2):360-8. doi: 10.1093/humrep/deq349. Epub 2010 Dec 16.

Homburg R1. “Clomiphene citrate—end of an era? A mini-review.” Hum Reprod. 2005 Aug;20(8):2043-51. Epub 2005 May 5.

Medications for Inducing Ovulation: A Guide for Patients. American Society for Reproductive Medicine.

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