Definition: Ovarian hyperstimulation syndrome (OHSS) is an overreaction of the ovaries to fertility drugs that stimulate egg growth. The Gonal-f label says it can progress rapidly to a serious condition with fluid build-up in the abdomen, chest and around the heart, and blood clots.
The Gonal-f label (section 5.3) says OHSS develops after treatment stops, peaking about 7 to 10 days later. It is more common, more severe and lasts longer if pregnancy occurs. Women are watched for at least two weeks after the hCG trigger shot.
The Cetrotide label says hCG is not given if the ovaries show an excessive response, to reduce the chance of OHSS.
| Label and study | Reported rate |
|---|---|
| Gonal-f RFF, ovulation induction study | Ovarian hyperstimulation 7.2% |
| Gonal-f RFF, ART (IVF or ICSI) study | Ovarian hyperstimulation 4.6% |
| Cetrotide, 949 women in controlled ovarian stimulation | Moderate or severe OHSS 3.5% |
These rates come from different study designs and drug combinations, so they cannot be compared directly.
Because OHSS peaks days after the last shot, the date of the trigger shot is the key reference point. A log of every stimulation shot and the trigger, with times, gives your clinic the timeline the label describes. If belly swelling or other new symptoms start, note the date as well. The Gonal-f label has no boxed warning; OHSS, allergic reactions and multiple births are its main warnings.
Read more on Dose Track: Gonal-f side effects · Cetrotide side effects · Menopur vs Gonal-f