Oral fertility medications are a treatment of choice for basic fertility care.
Oral Fertility Medications: Clomid
Clomiphene (Clomid, Serophene) is a medication that has been used for more than 50 years to stimulate follicular development. We still use this drug as it is very effective, safe and inexpensive.
Clomid is a SERM (Selective Estrogen Receptor Modulator), it can bind to the estrogen receptor, but depending on the tissue, it may stimulate it or block it. In the brain it blocks the estrogen receptor, resulting in the brain releasing more FSH, improving ovarian response and follicular development as measured by the number of follicles/eggs produced and the progesterone level.
Clomiphene is dispensed as 50 mg tablets and is capable of inducing ovulation in 80% of users but only half of those conceive over 6 months. The usual pregnancy rate per cycle is 10-15%, even with intrauterine insemination (IUI). The chances of conceiving per cycle are about the same on the 1st 3 ovulatory cycles but decrease thereafter, such that 90% of pregnancies from clomiphene occur by the fifth cycle.
At IVFMD we are very proactive and maximize your pregnancy rates per cycle by modifying your Clomid dose, incorporating other strategies such as Metformin, Dexamethasone, HCG and even FSH injections.
If there are no pregnancies after 3 or more cycles or there is no response, often we will consider laparoscopy, injectable gonadotropins with IUI, and in some cases IVF.
You usually only need only 2 sonograms during the cycle, one initially to confirm that your pelvic anatomy is normal, and another to assess your response to the medication, predict the best day for insemination, and determine if there are any negative side effects, such as a thin endometrial lining. The endometrium is the site in the uterus where the pregnancy implants. This tissue thickens with estrogen.
Clomid can bind at the endometrial level and in some patients prevent the action of estrogen and thus cause a thin lining. The higher the dose, the more often we observe this side effect which can lead to lower implantation levels. In some cases we can minimize the effect of Clomid on the endometrium by changing the dose, supplementing with Estrogen tablets, or switching to Letrazole. Other common temporary side effects are headache, hot flushes, and alterations of the cervical mucous. The rate of multiples on Clomid is 7-10%, and 90% of these are twins.
Oral Fertility Medications: Femara
Letrozole (Femara) is a newer medication that belongs to the family of Aromatase Inhibitors. This drug rapidly lowers Estrogen levels, stimulating the Pituitary to release more FSH and thus induce ovulation. Letrazole is commonly used in breast cancer patients to lower recurrence by decreasing estrogen levels.
A small Canadian study in 2005 reported an increased incidence of birth defects with Letrazole but this has been disproved by larger, better designed studies that followed. The half life of Letrazole is very short and thus it is out of the body by the time pregnancy occurs. We, as many other fertility specialists, feel that this is an excellent alternative for patients. Letrazole carries a lower risk of multiples and no endometrial effects when compared to Clomid.
Because this is a newer drug, Letrazole is more expensive than Clomid. Hot flashes can be experienced but are self limited. This medication was originally intended for breast cancer treatment and its use in fertility medicine is off-label.