Prevention of Ovarian Hyperstimulation Syndrome: A Review

Table 1

Summary of recommendations for strategies to prevent OHSS.

Intervention	Recommendation	Effect of intervention	Level of evidence
Reducing gonadotrophin dose	Recommended	“Step-up  regimen” has a lower risk of OHSS, cycle cancellation from hyperstimulation, and higher rate of monofollicular ovulation in contrast to other protocols	1b, 4
Reducing gonadotrophin duration	Utilized as clinically appropriate	“Mild”  stimulation  protocol with GnRH antagonist for late suppression has a lower risk of OHSS and multiple pregnancies and is cost effective	1b
		It also is less effective in terms of pregnancy rates than “long” protocols	1a
Individualized COS; (iCOS)	Further research required	iCOS  can reduce OHSS rates and associated cycle cancellations. It also produces a significant oocyte yield and good pregnancy rates	1b, 2a
GnRHa as an ovulation trigger	Recommended	GnRHa  use virtually eliminates OHSS rates	1b
hCG as an ovulation trigger	Further research required	Lowest dose of hCG does not seem to reduce OHSS rates	2a, 2b, 4
Adjuvant metformin therapy	Recommended	Metformin  is associated with a lower risk of OHSS and increased clinical pregnancy rate	1a, 4
Cabergoline	Recommended	Cabergoline  reduces the incidence of OHSS without an effect on pregnancy rates	1a
Hydroxyethyl starch	Utilized as clinically appropriate	HES  causes a decrease in OHSS without an effect on pregnancy rates	1a
Coasting	Further research required	Coasting  does not completely prevent OHSS, is associated with a lower oocyte yield, and has no benefit in contrast to other interventions. The protocols are also very diverse	1a, 4
Cryopreservation	Utilized as clinically appropriate	Cryopreservation  alone does not reduce rates of OHSS	1a
		GnRHa  followed  by  cryopreservation  virtually eliminates OHSS	1b
Cycle cancellation	Utilized as clinically appropriate	Cancellation  completely eliminates risk of OHSS but has a high financial and emotional burden	4
Adjunct GnRHa use	Not recommended	GnRHa use increases the associated costs and rate of OHSS while lowering the pregnancy rates	1a
Aromatase inhibitors for OI	Not recommended	AIs  have shown no reduction in rates of OHSS in contrast to other methods of OI	1a
rhLH	Not recommended	rhLH  use  does not reduce the risk of OHSS and has higher costs and lower pregnancy rates	1a, 1b
hCG for luteal phase support	Not recommended	Progesterone  significantly reduces the risk of OHSS with improved clinical pregnancy rates and live birth rates in comparison to hCG for LPS	1a
Albumin infusion	Not recommended	Albumin  does not reduce OHSS rates and may cause lower pregnancy rates. There are also associated risks with anaphylaxis and disease transmission	1a
Vasopressin V1a receptor antagonist	Further research required	It appears to reduce the ovarian weight gain and multiple corpus luteum development in OHSS	2b

Glossary for levels of evidence, 1a: systematic review and/or meta-analysis; 1b: ≥one RCT; 2a: ≥1 well-designed controlled study without randomization; 2b: ≥1 well-designed quasi experimental study; 3: ≥1 well-designed descriptive study; 4: committee or expert opinions.