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Prevention is the key to reducing the suffering of this terrible condition.
What causes OHSS?
OHSS is caused by the combination of two factors:
- too many eggs developing on the ovary under the influence of FSH
- the presence of luteinizing hormone (LH) or human chorionic gonadotrophin (HCG) – either of these hormones are injected as “trigger” injections, to release the eggs prior to a planned oocyte or egg collection. HCG is the hormone produced during pregnancy and therefore if a woman with OHSS becomes pregnant the condition of OHSS will persist for many weeks and become increasingly severe as the level of pregnancy hormone rises
Both factors must be present together to produce OHSS. This means that if only a few eggs develop on the ovary a woman is unlikely to get OHSS. If a woman who has many enlarged eggs on her ovary is not given any LH or HCG she will not get OHSS.