Ovarian Hyperstimulation Syndrome (OHSS)

This is the most serious consequence of induction of ovulation in Assisted Reproduction Technology. This condition can be fatal and therefore one should aim at preventing its occurrence, and to have strategies of ways of stopping the cascade at its earlier stages. It is certainly an avoidable syndrome should strict policies be implemented. However if it happen inadvertently despite all the measures taken to prevent it, aggressive treatment should be implemented without delay and not to under diagnose


Recognizing Risk Factors

  • Women with Polycystic ovarian syndrome (PCOS)
  • Women younger than 35 years
  • Slim built women
  • Higher oestrogen level
  • More than 10 ovarian follicles on ultrasound
  • Use of GnRH agonist for down regulation
  • Use of HCG or combined FSH/LH injections
  • Previous OHSS

Strategic Measures To Avoid OHSS

  • Ovarian stimulation – aim at not more than 10 follicles.
  • Coasting – reduce the dose or stop ovulation stimulation while continuing with down regulation for few days if noticed earlier evidence of OHSS.
  • Oestrogen – monitor oestrogen and allow few days for the levels to be reduced before proceeding to egg collection.
  • Egg collection – make sure that all follicles have been aspirated even the smaller ones. If more than 10 follicles noticed, risk of OHSS much higher.
  • Embryo Freezing – all embryos should be frozen to be used at a later cycle after at least one hormonal free manipulation cycle.
  • HCG – withhold the HCG and canceling treatment cycle.
  • Sexual intercourse – as pregnancy will tend to exacerbate the condition, even sexual intercourse in this treatment cycle should be avoided.


Recognizing The Presentation

Symptoms of mild hyperstimulation may occur during the treatment cycle as the aim of ovulation induction is to have controlled hyperstimulation. However, moderate and severe symptoms usually occur 6-8 days after the treatment ends.


Mild OHSS

Abdominal bloatedness, feeling of fullness, nausea, diarrhea, slight weight gain. This is due to larger than normal ovaries, high level of oestrogen and progesterone, digestive system upset and fluid imbalance. In this case, it is recommended to avoid sexual intercourse and over activities like heavy lifting, straining or exercise. Plenty of clear fluid drinking and avoiding fizzy drinks.

Moderate OHSS

As in the mild form, plus there would be weight gain more than 2 lbs (1 kg) a day. Increased abdominal girth causing feeling of tight clothes. Vomiting and diarrhea, darker colored urine and reduced amount. Feeling of thirst as well as dry hair and skin. This is caused by higher levels of hormones, fluid and electrolyte imbalance which causes dehydration because body fluids collect in the abdomen and in the other tissues. This in turn causes severe bloatedness and pelvic pain. In this case, correction of the fluids and electrolyte imbalance is mandatory.


Severe OHSS

Obvious fullness and bloatedness up to umbilicus is noticed. Abdominal and pelvic pain with tenderness, shortness of breath, marked reduction in urine production with darker color. Calf pains and chest pains may occur. In this situation extremely large ovaries with multiple follicles are noted. Fluid collects in the abdominal cavity (ascites), around the lungs (pleural effusion) as well as in tissues (oedema). In this situation, correction of the fluids and electrolytes imbalance is needed. In addition, aspiration of the excess fluids maybe required as well as administration of certain medications like steroids, heparin and albumin.

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