Live birth after frozen-thawed oocytes matured in vitro in a PCOS patient: a model for improving implantation rates in IVM cycles and objectively assessing the real potential of development of frozen oocytes matured in vitro

Comparison of GnRH agonist and hCG for priming in vitro maturation cycles in cancer patients undergoing urgent fertility preservation

In vitro maturation (IVM) of oocytes retrieved at germinal vesicle or Metaphase I stage, followed by vitrification of Metaphase II (MII) oocytes, has recently emerged as an option for urgent fertility preservation (FP). Priming is usually achieved with an injection of hCG, 10,000 IU, 36 hours before retrieval. This study aimed to assess a new method of priming, using GnRH agonists, and compare it to hCG, in cancer patients undergoing urgent FP. From 2009 to 2015, 373 cancer patients underwent MII oocyte cryopreservation after IVM cycles primed either with GnRHa (triptorelin 0.2 mg) (n = 138) or hCG (10,000 IU) (n = 235). Patients’ characteristics were comparable between the two groups. The number of COC retrieved was significantly higher in the GnRHa group (9.1 ± 6.8 versus 7.7 ± 5.5 oocytes, p = 0.04). However, the maturation rates (59 ±25% versus 64 ±26%, p = 0.07, respectively), and the total number of MII oocytes frozen (5.2 ±4.2 versus 4.9 ±4.0, p = 0.6, respectively) were similar between the GnRha and hCG groups. We did not find any difference between GnRHa and hCG priming for IVM. GnRHa priming is more physiological since it stimulates endogenous FSH and LH activity, and is well suited for FP in hormone-sensitive cancers and urgent cases.

In vitro maturation (IVM) of oocytes recovered from ovariectomy specimens in the laboratory: a promising "ex vivo" method of oocyte cryopreservation resulting in the first report of an ongoing pregnancy in Europe

PURPOSE

We present our center's experience with 34 consecutive cases who underwent in vitro maturation (IVM) of oocytes obtained from ovariectomy specimens and compare our data with updated literature data.

METHODS

Feasibility and efficiency of oocyte collection during ovarian tissue processing was assessed by the recovery rate, maturation rate, and embryological development after IVM.

RESULTS

On average, 14 immature oocytes were retrieved per patient during ovarian tissue processing in 33/34 patients. The overall maturation rate after IVM was 36%. The maturation rate correlated with the age of the patient and the duration of IVM. Predominately, oocyte vitrification was performed. Eight couples preferred embryo cryopreservation. Here, a 65% fertilization rate was obtained and at least one good-quality day 3 embryo was cryopreserved in 7/8 couples. The retrieval of oocytes ex vivo resulted in mature oocytes or embryos available for vitrification in 79% of patients. One patient with ovarian insufficiency following therapeutic embolization of the left uterine and the right ovarian artery because of an arteriovenous malformation had an embryo transfer of one good-quality warmed embryo generated after IVM ex vivo, which resulted in an ongoing clinical pregnancy.

CONCLUSIONS

IVM of oocytes obtained ex vivo during the processing of ovarian cortex prior to cryopreservation is a procedure with emerging promise for patients at risk for fertility loss, as illustrated by the reported pregnancy. However, more data are needed in order to estimate the overall success rate and safety of this novel approach.