If abdominal ultrasound
is performed then the follicles are usually approximately 2 mm smaller. On Clomid
) or Femara
i usually trigger ovulation
with HCG approximately 18 to 20 mm. With gonadotropins
i normally trigger ovulation around 20 -21mm. Patients with pcos or polycystic ovarian syndrome triggering ovulation needs to be somewhat later at approximately 21 to 22 mm.