Pharmacotherapy of partial tube blockage

Pharmacotherapy of partial tube blockage can be used in women, which have blocked only one Fallopian tube and the remaining one is otherwise healthy and capable of ovulating. 

The main drugs, which is using to help increasing the likelihood that woman will ovulate and become pregnant, is Clomifene.

Clomifene (previously clomiphene) is an orally administered, non steroidal, ovulatory stimulant. Clomifene is capable of interacting with estrogen-receptor-containing tissues, including the hypothalamus, pituitary, ovary, endometrium (the inner functional layer of the uterus) , vagina, and cervix.

The first endocrine event in response to a course of clomifene therapy, is an increase in the release of pituitary gonadotropins. This initiates the production of steroids and the production of follicles resulting in growth of the ovarian follicle and an increase in the circulating level of estradiol. Following ovulation, plasma progesterone and estradiol rise and fall as they would in a normal ovulatory cycle. Clomifene can lead to multiple ovulation, and hence increasing the risk of twins. 

The following procedures may be used to monitor induced cycles: 

• Follicular monitoring with vaginal ultrasound, starting 4–6 days after last pill. Serial transvaginal ultrasound can reveal the size and number of developing follicles.
• Serum estradiol levels, starting 4–6 days after last pill.
• Post-coital test 1–3 days before ovulation to check whether there are at least 5 progressive sperm per high-power field (HPF).
• Adequacy of lutenizing hormone (LH) surge by urine LH surge tests 3 to 4 days after last clomifene pill.
• Mid-luteal progesterone, with at least 10 ng/ml 7–9 days after ovulation being regarded as adequate.

It is not recommended by the manufacturer to use clomifene for more than 6 cycles.

Success factors

Proper timing of the drug is important; it should be taken starting on about the fifth day of the cycle, and there should be frequent intercourse.

Pharmacotherapy can be successful only in women, which has ovaries capable of ovulating. 

Failure factors

This treatment does not work in case of blockage on both sides. Surgical options or assisted reproduction techniques are required in these cases.

In comparison to purified follicle stimulating hormone (FSH), the rate of ovarian hyperstimulation syndrome is low.

The most common adverse drug reaction associated with the use of clomifene (>10% of people) is reversible ovarian enlargement. 

Less common effects (1-10% of people) include visual symptoms (blurred vision, double vision, floaters, eye sensitivity to light), headaches, hot flashes, light sensitivity and pupil constriction, abnormal uterine bleeding and/or abdominal discomfort. 

Rare adverse events (<1% of people) include: high blood level of triglycerides, liver inflammation, reversible baldness and/or ovarian hyperstimulation syndrome. 

Clomifene can lead to multiple ovulation, hence increasing the chance of twins (10% of births instead of ~1% in the general population) and triplets.

There may be an increased risk of ovarian cancer, and weight gain.

Clomifene is useful in those who are infertile due to anovulation or oligoovulation (inconsistent or irregular ovulation). Evidence is lacking for the use of clomifene in those who are infertile without a known reason. In such cases, studies have observed a clinical pregnancy rate 5.6% per cycle with clomifene treatment vs. 1.3%–4.2% per cycle without treatment.