Prevention and Management of Ovarian Hyperstimulation Syndrome (OHSS)

ART (assisted reproductive technology): All treatments or procedures that include the handling of human eggs or embryos to help a woman become pregnant. ART includes, but is not limited to, in vitro fertilization (IVF), gamete intrafallopian transfer (GIFT), zygote intrafallopian transfer (ZIFT), tubal embryo transfer, egg and embryo cryopreservation.

Cryopreservation: The process of slow freezing or vitrification to preserve biological material (e.g. gametes, zygotes, cleavage-stage embryos, blastocysts or gonadal tissue) at extremely low temperatures.

Embryo transfer: Placement of embryos into a woman’s uterus through the cervix after IVF. In zygote intrafallopian transfer or gamete intrafallopian transfer, zygotes or gametes are placed in a woman’s fallopian tube.

Embryo: The biological organism resulting from the development of the zygote, until eight completed weeks after fertilization, equivalent to 10 weeks of gestational age.

Implantation: the attachment and subsequent penetration by the zona-free blastocyst (usually in the endometrium) that starts 5 to 7 days after fertilization.

Informed consent: All those who are to give their consent should be given an oral explanation, supported by written information in plain language that is provided to them in sufficient time for it to be taken away, read and considered, before the giving of consent to any ART procedure, or any significant step in the procedure that requires consent. This explanation should be given with sensitivity to cultural diversity and accessibility to those with low literacy, disability, and/or those whose first language is not Arabic.

OHSS (Ovarian Hyperstimulation Syndrome): Ovarian hyperstimulation syndrome (OHSS) is an uncommon but serious complication associated with controlled ovarian stimulation during assisted reproductive technology (ART). OHSS is staged (mild, moderate, severe, or critical) by the severity of symptoms and laboratory findings. Ovarian hyperstimulation syndrome is further classified by the timing of onset (early or late).