Ovulation induction and embryo transfer
Ovarian stimulation protocols- Ovulation induction
During a normal cycle female organism produces 8-12 follicles, which mature gradually. After eight days only one emerges as dominant and reaches ovulation after 4 or 5 days. Couples that opt for IVF undergo certain medical treatment in order for more follicles to survive.
The kind and dosage of medications that will be used to induce multiple ovulation, is determined by the protocol that will be followed. Protocols, in other words the method of administration, are determined by infertility causes, the woman’s age, her hormone and biological characteristics, as well as the quality of male sperm.
Prior to ovarian stimulation, a sperm examination takes place so that possible problems can be detected early and treated accordingly. Sperm then is examined closely and spermatozoa that have a normal morphology and motility are isolated.
There are two main ovarian stimulation methods, the Long Protocol and the Short Protocol.
A long protocol lasts for about a month and is divided into two stages. The first stage involves the use of GnRH (gonadotropin releasing hormone) analogues (Arvekap, Daronda, Suprefact), starting on the 2nd or 21st day of menstruation, in order to achieve suppression of spontaneous ovulation. The treatment lasts from 10 days to 2 weeks. Ovulation suppression (otherwise called down-regulation) is monitored through ultrasound scan and estradiol levels estimation.
Once down-regulation is confirmed, we proceed with the second stage, which also lasts about two weeks. Ovarian stimulation commences and the woman takes gonadotropin injections (Puregon, Gonal-F, Altermon, Merional, Menopur).
A short protocol is generally recommended for older women that are more likely to be low responders to ovarian stimulation.
It lasts approximately two weeks and in contrast to the long protocol, suppression and stimulation occur almost at the same time. On the first days of the cycle a woman is administered GnRH agonist medications followed by gonadotropins.
Once growth of follicular diameter and estradiol levels are ideal, the woman is given an injection to induce final egg maturation and trigger multiple ovulation, and the patient is taken off medication.
Embryo transfer occurs a while after egg retrieval and is a painless procedure. Anesthesia is generally not required, but the woman is given a sedative as she needs to remain calm during the procedure. A soft transfer catheter is usually loaded with 3 or 4 embryos and inserted into the uterine cavity. Ultrasound guidance is used to ensure correct placement. Transferring more embryos is avoided as it carries the risk of miscarriage, multiple pregnancy and premature labour.
Single embryo transfer is recommended in specific occasions. It takes place in cases of women under 35, who are diagnosed with uterine disorders. Single embryo transfer significantly lowers the risk of multiple pregnancies and the danger they pose to the uterus. The truth is, though, that despite higher pregnancy success rates of this procedure, couples hesitate to opt for single embryo transfer.
Due to this reason patients need to be educated about single embryo transfer parameters and success rates.