What is ovulation?
Every month any one of a woman’s ovaries produces an egg (which is inside a follicle) which begins to grow after onset of menses (usually from day 8-9). This egg reaches maturity at about 18-22 mm size (about day 14) and then the follicle ruptures to release the egg which may now be fertilised by sperm. This process of egg rupture is known as ovulation. It usually happens on day 14-15 of a 28-30 day menstrual cycle.
What is follicular monitoring by ultrasound?
This process of the growth of the follicle can be observed on ultrasound examination. The sonography is preferably done internally wherein the follicles can be seen clearly. The follicular monitoring by ultrasound is done every alternate day starting from the 9th day of the menstrual cycle.
Most gynaecologists prefer to also do a baseline scan on the 2nd day of menses to check the size and number of follicles and the uterus. Antral follicle (AFC) count is the sum total of the total number of immature follicles in both the ovaries on day 2 or 3 of the cycle. A low AFC may indicate a poor ovarian reserve (poor stock of follicles available for maturation).
The ultrasound is performed every alternate day and the number and size of follicles in each ovary are assessed. At the same time, the thickness of the endometrium (uterine lining) is measured.
As the follicle grows, the uterine lining also becomes thicker. At the time of follicle rupture, the follicle should be preferably 18 mm or more in size and the endometrium should be at least 7 mm thick. A very thin lining cannot sustain pregnancy.
What do I expect during follicular monitoring?
Your gynaecologist would call you for ultrasound on days 2, 9, 11, 13, 14, 15 (roughly). Depending on your reports and medicine protocol, you may need scanning more or less frequently. When your follicle is mature, he/she may give you an injection (HCG) to rupture the egg. That is not always necessary though.
Around the time of egg rupture, you would be asked to have ‘planned intercourse’ at least every alternate day. Make sure your spouse is in town for those days.
After your follicle has ruptured, you may stop the ultrasound testing for that cycle. The gynaecologist may perform one more scan after 7 days of ovulation to check if your endometrium is well-prepared for the baby. You may be given progesterone capsules for vaginal insertion or certain tablets after ovulation to increase the blood flow to the ovary and give hormonal support to the fertilised egg (luteal phase support).
If you have conceived in the cycle, you will miss your period and a pregnancy test on the day after missed period (or 15 days after ovulation) would confirm it for you.
If you, however, do not conceive, you will get your period at the expected date or about 2 weeks after ovulation.
What do you mean by ovulation induction?
Ovulation induction means giving medicines and/or injections to help the follicles grow and subsequently rupture. Here, your gynaecologist takes over Nature’s role and facilitates egg growth.
Ovulation induction is useful for women with anovulatory infertility such as PCOS and irregular cycles. If you are ovulating, your fertility specialist may still choose to induce ovulation using medicines or injections. Here, he or she will try to grow more than one egg and/or get better quality eggs or thicker uterine lining so that the chances of pregnancy are better.
Ovulation induction may be combined with IUI also.
What do you mean by IUI?
IUI or Intrauterine insemination is a procedure wherein, during the ovulatory phase, your husband’s ‘washed semen sample’ is directly deposited into the uterus via a thin plastic IUI cannula. When your husband’s semen is ‘washed’, it is processed so that the best quality motile sperms are selected for deposition. Also, since the semen is deposited directly into the uterus, these sperms are very close to the fallopian tubes and this increases chances of fertilisation.
Are there any side effects of ovulation induction?
The commonest side effects of ovulation induction are:
Multiple pregnancy (twins and rarely triplets) - If more than one egg ruptures, both of them may get fertilised (or rarely three or more). This can lead to more than one fetus.
OHSS (ovarian hyperstimulation) - Ovarian hyperstimulation is a relatively dangerous side-effect of ovulation induction which is fortunately rare. Here, due to many large follicles growing to maturity, the hormonal (E2) levels rise to dangerous levels and this causes release of chemicals which can cause collection of fluid in the abdomen and chest, low blood pressure, derangement of electrolyte levels in the blood and increased risk of clot formation in blood.
OHSS may be mild, moderate or severe. Mild OHSS needs only observation and monitoring.
The moderate variety needs strict vigilance with certain medicines and blood tests, which may require admission.
In severe cases, you may need to be hospitalised in ICU.
OHSS is much more common when injections are used for ovulation induction, esp in IVF or ICSI cycles.