Clomid, Serophene (Clomiphene Citrate)
Clomid was one of the first fertility drugs and OB/GYNS and infertility specialists use it extensively. Clomid is used to induce, or regulate, ovulation in women who ovulate irregularly, or not at all.
Clomid works at the hypothalamus, a small gland located at the base of the brain, to indirectly cause the pituitary to increase its production of follicle stimulating hormone (FSH). The hypothalamus “ works like a thermostat” regulating the levels of various reproductive hormones including FSH, LH, estrogen and others.
Clomid's Actions
Clomid works at the hypothalamus and it is necessary to have a basic understanding of how reproductive hormones interact to understand Clomid's actions. A typical menstrual cycle consists of the following steps:
1. During the first few days of the menstrual cycle, the hypothalamus begins production of gonadotropin releasing hormone (GnRh). GnRh travels through the bloodstream to the pituitary gland where it stimulates the production of FSH.
2. FSH stimulates the recruitment and development of the ovarian follicles, which are located on the ovaries. Each ovarian follicle contains one egg.
3. As healthy follicles develop, they increase production of estrogen, which helps prepare the endometrium to accept an implanting embryo. The hypothalamus “reads” this increase in estrogen and signals a corresponding reduction in FSH levels. Clomid works at the hypothalamus competing for estrogen "binding sites".
4. Once the FSH and estrogen levels indicate follicular maturity, a surge of luteinizing hormone (LH) is released by the pituitary. The surge of LH causes the egg(s) to be “ovulated” from the follicle(s). Fertility drugs, such as Lupron and Ganirelix block LH thus preventing ovulation
5. Progesterone also supports endometrial development and is initially produced by the “leftover follicle” or corpus luteum. Once the fetus forms, the placenta produces progesterone.
Clomid “competes” with estrogen receptors at the hypothalamus. Clomid “occupies” these receptors, which makes the levels of estrogen “appear ” to be lower than they actually are. Based upon these levels, the hypothalamus signals continued production of FSH causing follicular development.
Clomid Use - How Many Cycles
Clomid pregnancies are most likely to occur during the first three ovulatory cycles. Many well controlled clinical studies confirm this aspect of Clomid treatment. Treatment beyond three to six cycles is not generally recommended and there is no advantage to increasing the dose of Clomid once ovulation is occurring.
Clomid is sometimes prescribed by generalists far beyond these recommended treatment periods. Extended use of Clomid is expensive, stressful, and unlikely to result in pregnancy. We also see Clomid patients whose spouses have not had a semen analysis. Our standard fertility workup always includes a semen analysis performed by an experienced fertility laboratory.
In appropriate women, we administer Clomid from three to six cycles once ovulation is occurring. Oftentimes, we follow follicular development with ultrasound monitoring.
After this time, patients are offered the next step in the treatment process, which may be either Femara or FSH stimulated intrauterine insemination (IUI). This “next step” is dependent upon many factors including the female’s age, cause(s) of infertility, financial considerations, and others.
Clomid Side Effects
Clomid side effects can include ovarian enlargement, increased risk of multiple births (8-10% twin rate; 1% or less triplet rate), hot flashes, visual disturbances and nausea. See the manufacturers Web site for a full description of potential side effects.