Clomid Gives More Women a Chance at Conception
Clomid is the brand name for clomiphine citrate, a member of a class of drugs called the SERMs (selective estrogen receptor modulators). Clomid is known as the original fertility medication and was first developed in the 1960s, interestingly, as a potential contraceptive. Very quickly however, Clomid’s ability to improve fertility was recognized, and it was therefore marketed to help women conceive.
How does Clomid work?
To understand how Clomid works requires a small amount of background information on normal reproductive function. “Normal” ovulation (release of an egg from the ovary) is the result of the brain sending a signal to the ovary, over a 2-week period, with a hormone called FSH (follicle stimulating hormone). When the ovary receives this signal, eggs begin growing and producing estrogen. The estrogen travels back to the brain, telling it that the ovary is doing its job (making eggs). Once the brain receives this confirmation, it stops sending stimulation (FSH) to the ovary.
Clomid works by blocking estrogen at the level of the brain (the hypothalamus). This causes the brain to think that the ovaries are not doing their job (making eggs) and therefore, it sends down more stimulation (FSH) to the ovaries. Thus, several eggs may develop at once. Alternatively, in women who do not normally ovulate, Clomid usually induces one egg to develop.
Who should take Clomid?
Clomid is a useful medication for women who are trying to conceive but having difficulty due to unexplained infertility, mild male factor infertility or anovulation (PCOS and others). Women with tubal factor infertility, severe male factor or uterine factor will not benefit from Clomid.
What is the normal dose of Clomid/How is Clomid taken?
Clomid comes in 50 mg tablets. The starting dose is usually 50 -100mg per day for five days. Most physicians prescribe the medication to be taken between days three and seven of the menstrual cycle. For women who do not respond to the starting dose, higher amounts can be taken (up to 250mg per day). However, the success rate tends to fall as the dose increases.
What are the success rates with Clomid?
Success rates with Clomid depend on a few variables, including the cause of infertility (anovulation vs. unexplained vs. male factor), and if an IUI (intrauterine insemination) is combined with the treatment.
In patients with unexplained infertility, Clomid alone (without IUI) increases the monthly pregnancy rate by two times (from 2% to 4%). If an IUI is added, the pregnancy rate jumps to about 8%.
In patients with anovulation (PCOS, etc.), Clomid alone increases the monthly pregnancy rate to between 7% and 18%. Presumably, this rate is higher with IUI added in for good measure.
The chance for twins with Clomid is approximately 7%, triplets is <1%
Are there any side effects to Clomid?
The most common side effect of Clomid is hot flushes. This is likely due to the estrogen blocking properties of the drug. Fewer women complain of abdominal discomfort, nausea and vomiting. Rarely, some women experience visual changes such as double vision or blurring.
Some women complain of moodiness or anxiety with Clomid. Importantly, the entire experience of going through fertility treatment can be anxiety provoking. It is difficult to determine if the Clomid alone causes or exacerbates these feelings, but nonetheless, they are common feelings that, when acknowledged, tend to be manageable and temporary.
One other side effect of Clomid is a blocking effect in the uterus. Just as Clomid blocks estrogen in the brain, it also blocks some estrogen in the uterine lining. This may result in a thin uterine lining in women who are taking Clomid. Many experts believe this is the reason that Clomid success rates are not higher.
What are the alternatives to Clomid?
There are alternatives to Clomid. One medication, Letrazole, is also a pill which is taken in the same fashion as Clomid. Its mechanism of action is somewhat different, but the results are similar. For patients who do not respond to or cannot tolerate Clomid, Letrazole is a viable alternative.
Injectable medications (gonadotropins) are another alternative to Clomid. These medications are purified or synthetic forms of the hormones made in the brain that stimulate the ovaries. The medicines can work when a patient is resistant to Clomid. Importantly, they tend to be quite a bit more expensive and carry a greater risk for twins, triplets or more.