Management If outpatient management is appropriate, the patient should be instructed to limit her activity, to weigh herself daily, and to monitor her ﬂuid intake (at least 1 L per day of mostly electrolyte-balanced ﬂuid) and output. Daily follow-up by telephone or visit is important and the patient should be reassessed if she notes worsening of the symptoms or if her weight gain increases to more than 2 lb per day. Indications for hospitalization include an inability to tolerate oral hydration, hemodynamic instability, respiratory compromise, tense ascites, hemoconcentration, leukocytosis, hyponatremia, hyperkalemia, abnormal renal or liver function, and decreased oxygen saturation. Fluid intake and urine output need to be carefully measured, and admission to an intensive care setting can be considered if the patient has hyperkalemia, renal failure, respiratory failure, or thromboembolic disease. Although intravenous ﬂuids may worsen ascities, they are essential to correct hypovolemia, hypotension, electrolyte abnormalities, and oliguria. Albumin 25% can be dosed 50 to 100 mg intravenously every 4 to 12 hours if further intravascular volume expansion is needed. Diuretics can be considered to improve weight gain and oliguria only after hypovolemia has been corrected. Thromboembolic prophylaxis should be given. Single or repeated transvaginal or transabdominal ultrasound-guided paracentesis may relieve pain, hydrothorax, or persistent oliguria. Rapid large-volume ﬂuid removal can be considered, as compensatory ﬂuid shifts are unlikely to occur in this typically young healthy population as long as the patient is carefully monitored (398).
Prevention No method will prevent OHSS completely, but steps can be taken to decrease risk. Careful gonadotropin stimulation for monofollicular development is discussed under “Ovulatory Factor.” For ART, stimulation protocols for high-risk patients include lower initial COH doses of 150 IU and GnRH antagonists for LH surge prevention, which reduce the total dosage and duration of gonadotropin stimulation (401,402). Reintroduction of GnRH antagonists following retrieval may be of benefit (351).
Decreasing the dose of hCG to reduce the incidence of OHSS is controversial (401,402). Exogenous recombinant LH is available for COH, but the dose required to trigger ovulation has not been established (402). The very short half-life of endogenous LH may in turn reduce the incidence and/or severity of OHSS (351). GnRH agonists can be used instead of hCG during antagonist cycles to induce an endogenous LH surge. As GnRH agonist triggers are associated with lower pregnancy rates, these may be a better option for oocyte donors or for patients who are not planning a fresh embryo transfer (351,402).
Coasting may be considered when estradiol levels are less than 4,500 pg/mL and/or there are 15 to 30 mature follicles present. During coasting, gonadotropin stimulation is withheld and estradiol levels are checked daily (351). An initial rise of estradiol is typically observed within the first 48 hours of the coast, but the levels should subsequently plateau or decrease (402). The patient may then be triggered when serum estradiol levels fall to less than 3,500 pg/mL. If GnRH agonists are used for initial LH surge suppression, switching to an antagonist during the coast has been associated with improved outcomes (351).
The cycle should be cancelled and the trigger withheld if there are greater than 30 mature follicles, the coast duration is more than 4 days, or if estradiol levels rise to more than 6,500 pg/mL during coasting (351,402).