Before starting ovulation induction

Before ovulation induction is started, exclude pregnancy and perform standard initial investigations on both partners (including a semen analysis).

Tests performed by specialists (or general practitioners with experience in fertility treatments) to assess fallopian tube patency and uterine anatomy include hysterosalpingogram, hysteroscopic contrast sonography (HyCoSy) and laparoscopy with dye tests. These should be performed:

• before ovulation induction if the female has a history of pelvic infection or surgery
• after 3 to 6 cycles of letrozole or clomifene if the female does not conceive despite confirmed ovulation
• if planning to use FSH.

The timing of ovulation induction by a specialist may depend on the individual’s hormonal profile. Induction can be started in those who are amenorrhoeic if they have basal hormones typical of the follicular stage. Some clinicians don’t assess basal hormones and instead give a short course of a progestogen to induce uterine bleeding; this may make the endometrium more suitable for implantation later in the cycle. Pretreatment with a progestogen can also be useful to guide the specialist choice of ovulation induction drug. If a bleed does not occur after taking a progestogen, letrozole or clomifene are unlikely to be effective (because serum estradiol is likely too low for the drugs to suppress estrogenic feedback on the hypothalamus), and gonadotrophins are preferred.

A typical progestogen pretreatment regimen is: