In the case of artificial insemination with induced or stimulated cycle, the ovulation is induced before the moment of insemination. The treatment starts with a vaginal ultrasound on the second or third day of the cycle, to check that the ovaries are resting and that the ovarian stimulation can commence.
At this moment, the ovarian induction process starts. To do so, the woman gets injected with a hormone (FSH, follicle stimulating hormone) according to the instructions of her specialist. The aim of this stimulation is to obtain 2 or maximum 3 follicles. The process is controlled by means of ultrasound, until it is detected that there are between 1 and 3 follicles of adequate size, i.e. larger than 17 or 18 mm. At this moment, the maturation of the egg cells of the follicles is induced by injecting hCG. The insemination is programmed with in the next 36 hours after the injection of this last hormone.
The ultrasound checks are fundamental to avoid the risk of multiple pregnancies. At times, the ovaries react more strongly than expected and it is then necessary to cancel the cycle. In an ovarian induction cycle for artificial insemination normally two or three ultrasounds are needed.
The main advantage of ovulation induction is that the pregnancy rates are higher (around 20-25% per attempt). The inconvenience however, is that the risk of twin pregnancies is increased (up to 20% of all pregnancies). This also involves extra costs for the treatment.
In women of over 38 we should consider ovarian induction from the start, to increase the chances of success. In women of less than this age, it is possible to start the treatment during the natural cycle.