Ovulation & Timed Intercourse
This is the simplest form of assisted reproduction treatments. It entails minimal risks and inconvenience to the patient while being relatively inexpensive.
Timed intercourse can be programmed either during a natural cycle or using a simple ovarian stimulation protocol. With the first approach, the patient is requested to receive 2-3 ultra sound scans aiming at assessing the ovaries for the development of the single follicle (or sometimes two) and to determine the exact time of ovulation therefore programmed intercourse can be advised duly.
With the medicated approach the patient is prescribed simple oral medication which can be supplemented by low dose hormonal analogue injections aiming at promoting a small number of follicles to develop into the ovaries. The response to this medication is monitored by regular ultra sound examinations and at times with estrogen blood tests normally starting as early as day 7 from the onset of medication administration. The exact day of ovulation is scheduled by the administration of a triggering hormonal injection when at least one follicle had reached 18 mm in mean size with another one or two at 16-17 mm. Advice is then given regarding an optimal time (approximately 36 hours later) for the couple to engage into sexual intercourse. While the endeavour is to induce the ovary to mature a small number of follicles in either of the two ovaries the inner part of the uterus namely endometrium where embryos implant must grow to a satisfactory size (>7 mm) for optimal results. In this respect, the patient may be advised to administer estrogen and/or progesterone supplements for additional support starting from the day of ovulation confirmation.
Non – medicated induction of ovulation
Non – medicated induction of ovulation can be beneficial to younger in age recipient patients with regular menstrual cycles and who have previously tried to conceive for a minimum of 13 months following regular unprotected intercourse. Similarly medicated ovulation induction may be advantageous to couples where the female spouse presents polycystic ovaries associated with irregular menstrual cycles and anovulation. Both treatment modalities entail that the male partner has good semen parameters consistent with optimal density, motility and morphology and that the female spouse’s fallopian tubes are patent. The success rates vary between 15-20% for either of the two treatment modalities.
There are three main approaches to O.I drug treatment
most commonly used today:
While the use of these compound had been developed to assist women with anovulation (most commonly associated with PCOS), it is often used to stimulate the growth of additional follicles in women who have normal ovulatory cycles. Clomiphene citrate acts by blocking the estrogen receptors in the ovaries thereby stimulating the hypophysis to release higher concentrations of FSH optimizing response.
The nominal starting dosage is 50mg daily starting from day 2 or 3 from the onset of a menstrual cycle (day 1 is considered the day of normal blood flow) and for 5 days. An ultra sound scan to assess follicular recruit is undertaken following completion of medication course and based on the findings the patient pursues a series of hormonal injections for the following days so the follicular number acquires a uniform development and is not allowed to regress.
Once the leading follicle had reached a mean size of 18-20 mm and another two precede at 16-18mm the final (ovulation triggering) injection is administered at a specified time so the couple is advised of the best time to have intercourse.
Letrozole belongs to a class of medications known as aromatase inhibitors and in this respect, they act by inhibiting the release of an enzyme called aromatase which is responsible for the production of estrogen in the organism. While the end product of Letrozole and Clomiphene citrate activity is to induce production of FSH (and LH) by the pituitary gland their mode of action is different. The estrogen insufficiency which may result from Clomiphene citrate administration may adversely affect the status of the cervical mucus along with compromising endometrial size since it is not metabolized fast in the body by contrast to Letrozole which is relatively short-acting and has no direct anti-estrogenic effects. The normal dosage of Letrozole is 2.5 mg daily and for 5 days starting from day 5 from menstrual cycle onset. On day 10 an ultra sound scan aiming at the assessment of ovarian response is scheduled followed by programming ovulation using a triggering compound.
These hormone injections are in essence FSH (follicle-stimulating hormone) produced either via recombinant laboratory technology or as a result of an elaborate purification process from the urine of postmenopausal women. They are administered by intramuscular or subcutaneous injections starting early in the menstrual cycle (or following confirmation of pituitary down regulation) and they endure for approximately 10-14 days. The initial dosage of these hormone injections is critical in the sense that it should aim into an optimal ovarian response (not too many and not too few follicles should be allowed to mature). It is therefore based on a large collection of parameters most important of which are the age and BMI, the appearance of ovaries on ultra sound, results of a hormonal profile on day 2 or 3 of a previous menstrual cycle, fertility manifestation, etc. On day 5-7 from the onset of this medication administration, a baseline ultra sound scan is arranged to assess initial ovarian response and a decision is made at the time pertaining to subsequent dosage. At least one additional ultra sound examination is arranged for final assessment prior to scheduling the time of ovulation with the use of a triggering hormonal compound (HCG).