Contrary to common suggestion, women are opting to freeze their eggs not to pursue education or careers but for reasons "mostly revolving around women's lack of stable partnerships with men committed to marriage and parenting." This is the conclusion of the largest qualitative study so far in elective egg freezing; 150 subjects from four IVF clinics in the USA and three in Israel were interviewed, each of whom had completed at least one cycle of oocyte cryopreservation for social reasons.

Results of the study are presented today by Dr Marcia Inhorn, an anthropologist from Yale University, USA, at the 34th Annual Meeting of ESHRE in Barcelona.

"The medical literature and media coverage of oocyte cryopreservation usually suggest that elective egg freezing is being used to defer or delay childbearing among women pursuing education and careers," said Inhorn. "Our study, however, suggests that the lack of a stable partner is the primary motivation."

Behind the claim lie in-depth interviews with 150 women who had chosen to freeze their eggs at fertility clinics in the USA (114 women) and Israel (36 women). The data from the interviews were qualitatively analysed and eventually indicated ten pathways which led the women to egg freezing.

The majority of women in the study (85%) were without partners at the time of egg freezing, reflecting six different life circumstances -- being single, divorced or divorcing, broken up from a relationship, working overseas, single mother by choice or circumstance, and career planning. Choosing elective egg freezing for planning a career was the least common of these six pathways, even among women who worked for companies with egg freezing insurance coverage.

Those with partners (15%) faced four different life circumstances -- with a man not ready to have children, in a relationship too new or uncertain, with a partner who refuses to have children, or with a partner with his own multiple partners. "Most of the women had already pursued and completed their educational and career goals," Inhorn explained, "but by their late 30s had been unable to find a lasting reproductive relationship with a stable partner. This is why they turned to egg freezing."

With only one exception -- freezing eggs before working overseas -- the pathways varied little among American and Israeli women in the study. Inhorn acknowledged, however, that these ten pathways to elective egg freezing may not be the same for women in other countries, but the shared responses of women in the two countries studied does suggest some generalisability.

advertisement

Elective egg freezing is one of the fastest growing services in many fertility clinics today. Its growth took off after the widespread introduction of vitrification, a fast-freezing technology which reduces cells to a glass-like state in just a few seconds. Before then egg freezing was inefficient, usually causing damage from ice crystals to the egg's microstructure. Dr Pasquale Patrizio, a Yale fertility specialist and co-investigator on the study, adds that around 5000 egg freezing cycles were performed in the USA in 2013, but that 76,000 are predicted in 2018.

Now, with such a dramatic increase in the numbers choosing to freeze their eggs and clinics offering the service, Inhorn said that "clinicians must be aware of the role that partnership 'troubles' play in the lives of egg freezing patients and make patient-centered care for single women a high priority."

She thus described the well publicised schemes of companies offering egg freezing to their female staff as "a legitimate insurance benefit," even if careers are not the reason why most women are freezing eggs. And the majority with partnership problems? "Their choices are to freeze their eggs, hope to find a partner, or decide to become a single mother with donor sperm," she said. "But freezing eggs holds out hope for many."

Meanwhile, the clinical outcome of elective egg freezing remains unclear, with few women so far thawing and using their eggs. Patrizio suggests from available data that in general it seems advisable for women under 35 years old to cryopreserve 10-12 eggs and for women over 35 around 20 eggs to have a reasonable chance of later pregnancy.

Notes

1. Vitrification, which is the only technology applicable to elective egg freezing, has been a mini-revolution in much of today's assisted reproduction. In egg donation it has made egg banking possible (and thereby removed the need for synchronised "fresh" cycles between donor and recipient) and encouraged more embryo freezing. Studies have shown that the survival and fertilisation rates of thawed vitrified eggs are no different from those of fresh.

2. Elective egg freezing should not be confused with fertility preservation for medical indications. This is usually to preserve fertility ahead of treatments for malignancy likely to destroy ovarian function. Egg freezing -- if there's adequate time -- is one possibility; in more urgent cases ovarian tissue cryopreservation is the most common procedure.

3. A 2017 study developing a model to predict a 75% chance of pregnancy for egg freezing found that 10 eggs were needed up to age 34, 20 eggs at age 37, and 61 eggs at age 42 (see Goldman RH, Racowski C, Farland LV, et al. Predicting the likelihood of live birth for elective oocyte cryopreservation: a counseling tool for physicians and patients. Hum Reprod 2017; 32: 853-859).