What is the maximum number of oocytes (eggs) that can be retrieved at one time during an egg retrieval procedure?

From the Guidelines

Typically, 8-15 eggs can be harvested at one time during an egg retrieval procedure, with the number varying significantly based on individual factors such as age and ovarian reserve. The number of eggs retrieved depends on several factors including age, ovarian reserve, response to stimulation medications, and the specific fertility treatment protocol used 1. Women undergoing ovarian stimulation with medications like follicle-stimulating hormone (FSH), luteinizing hormone (LH), or human menopausal gonadotropin (hMG) may produce more eggs than would naturally develop in a cycle.

Factors Affecting Egg Harvest

• Age: Younger women generally produce more eggs, while women over 35 may have fewer eggs retrieved, with the number of collected oocytes being age dependent, varying from 15.4 ± 8.8 in women <26 years of age to 9.9 ± 8.0 in women 36-40 years of age 1.
• Ovarian reserve: Women with a low ovarian reserve may have fewer eggs retrieved, and double stimulation can be considered in these cases, which requires 4 weeks of treatment and approximately doubles the number of oocytes retrieved 1.
• Response to stimulation medications: The quality of eggs is often more important than quantity, as not all harvested eggs will be mature or viable for fertilization.

Importance of Egg Quality

The goal of controlled ovarian stimulation is to obtain a reasonable number of quality eggs while minimizing the risk of ovarian hyperstimulation syndrome, a potential complication of fertility treatments. Recent data reported a cumulative live birth rate of 61.9% if 12 oocytes were cryopreserved in women 35 years of age and 43.4% if 10 oocytes were cryopreserved in women >35 years of age 1.

From the Research

Number of Eggs Harvested

• The number of eggs that can be harvested at one time is not directly stated in the provided studies 2, 3, 4, 5, 6.
• However, the studies discuss the use of GnRH antagonists and agonists in ovarian stimulation and their effects on oocyte quality, fertilization rates, and pregnancy outcomes.
• According to the studies, GnRH antagonists can reduce the risk of ovarian hyperstimulation syndrome (OHSS) and allow for the continuation of exogenous gonadotrophin administration 3, 6.
• The studies also report on the efficacy of GnRH antagonist protocols in preventing OHSS in patients at high risk of OHSS 6.
• In terms of oocyte quality and quantity, the studies suggest that GnRH antagonists can result in high oocyte quality, blastocyst development, and pregnancy rates 3, 4.
• However, the exact number of eggs that can be harvested at one time is not specified in the provided studies.

Ovarian Stimulation and OHSS

• Ovarian hyperstimulation syndrome (OHSS) is a major problem in IVF or ICSI cycles 6.
• GnRH antagonists can reduce the risk of OHSS by inducing a rapid decrease in LH and FSH, preventing and interrupting LH surges 2, 5.
• The use of GnRH antagonists can also result in a lower incidence of OHSS, as well as a reduction in the total number of follicles with a diameter >10 mm and E(2) levels on the day of HCG administration 6.

GnRH Antagonists and Agonists

• GnRH antagonists and agonists are used in ovarian stimulation to prevent LH surges and control follicular growth 2, 5.
• GnRH antagonists can replace GnRH agonists in controlled ovarian stimulation without their side-effects and long desensitization period 5.
• The studies suggest that GnRH antagonists can result in high oocyte quality, blastocyst development, and pregnancy rates, as well as a reduction in the risk of OHSS 3, 4, 6.