One week ago, in the beginning of July (2016), at the Annual Meeting of European Society of Human Reproduction and Embryology (ESHRE) in Helsinki, a large multicenter study was presented by Dr Karen Hunter Cohn at Celmatix (a medicine company focused on fertility and women’s health) providing strong evidence that freeze-all protocols are associated with significantly improved outcomes of in vitro fertilization (IVF). This was especially seen in women who underwent fertility treatment at the age of 35+ which is a group that is rapidly growing. In women over 35 the risks are higher and the efficiency rate is lower for conceiving a healthy baby, making this group the most challenging category of infertility patients.
More than 16,000 IVF treatment cycles were analyzed and examined in the study. All cycles were performed at 12 leading fertility centers in the US. The treated women received either frozen or fresh embryos during their infertility treatments and the results clearly favored frozen embryos over fresh. 46% of the women who received frozen embryos vs 33% of the women who received fresh embryos resulted in a pregnancy. Here all women were over 35 years old.
It is not a standard procedure to use a freeze-all approach as of today even though a few centers do freeze-all with all their patients. In most fertility clinics a freeze-all protocol is only used when the treated women are 1) at high risk for ovarian hyperstimulation syndrome (OHSS), 2) suffer from elevated levels of progesteron concentration prior to egg retrieval or 3) are having a preimplantation genetic diagnosis prior to embryo transfer.
The story so far
1. The idea of a freeze-all policy is not new in IVF, but is emerging as a broad technique for improving results, especially in older patients.
2. The idea was developed as part of a “segmentation” approach to avoid the risk of ovarian hyperstimulation syndrome (OHSS) in IVF. OHSS, the most serious treatment risk of IVF, is exacerbated by the hormone hCG, whose levels rise in pregnancy. The segmentation approach was designed to separate the ovarian stimulation segment from the pregnancy segment – and this separation simply required the freezing of all embryos until a later cycle.
3. But what began as a safety aim also suggested more overall benefits – particularly with the introduction of new freezing techniques (fast-freezing by vitrification) and scientific studies suggesting that ovarian stimulation itself and the hormones used may have a negative effect on the receptivity of the endometrium (uterus lining) for embryo implantation.
4. This is the largest study so far – though retrospective in its design – to assess the effect of a freeze-all protocol in a broad population of IVF patients
Abstract O-239, Wednesday 6 July 2016, 11.30: Multi-center study demonstrates freeze-all IVF protocols are correlated with higher ongoing pregnancy rates in women of advanced maternal age
The picture is from http://www.frozen.disney.com.au