Embryologist friendly programmed IVM with delayed blastocyst transfer

Abstract

To design an approach to IVM (in vitro maturation) which can be easily integrated into a busy IVF laboratory and which results in oocytes with a high maturation rate, a good blastocyst production rate, and a reasonable pregnancy rate. Our IVM protocol uses a programmed approach to enable scheduling cases and requires only laboratory techniques already used by the embryologist. Retrieval is designed to improve environmental conditions for oocytes. Embryos are transferred back in a subsequent FET cycle. Patients with a PCO pattern in their ovaries were recruited. Oral contraceptives were used to plan prospectively for a day for retrieval. Letrozole was started on day 5 after stopping oral contraceptives (SOC). FSH (25 to 75U/day) was started on the 7 after SOC. Ovidrel was given on day 11 or 12 after SOC. Oocyte retrieval was on day 13 or 14 after SOC. Cycles were cancelled if all follicles were less than 8 mm or if one follicle was greater than 13 mm. Oocyte retrieval used a Steiner-Tan needle to enable flushing and limit dead space in the oocyte collection system to 0.000004 ml. This needle is constructed from a 5 cm 19g needle attached to a 17g needle with fluid entering at the junction of these two needles. Flush fluid is simultaneously pushed into both the 19g and 17g needles. Aspiration while flushing is used to empty the 17g needle into the collection tube. Our objective was to get the oocyte into the laboratory as soon as possible after it was aspirated from the follicle. The large volume of flush also enabled the embryologist to use routine oocyte retrieval laboratory techniques to locate oocytes in the aspirate. Sage IVM maturation media with 10% heat inactivated maternal serum and 75 mIU FSH/ml was used. Oocytes were visually evaluated for maturity at retrieval and twice a day until 48 hours after retrieval. Mature oocytes were fertilized using ICSI. Zygotes were cultured to blastocysts. Blastocysts were vitrified on day 5 or 6 after ICSI. Oral contraceptives were used as patients transitioned into our routine FET program. Twenty patients were recruited. Two cycles were canceled for follicles that were too large. The average number of oocytes retrieved was 11. The average maturation rate was 85%. The average fertilization rate per mature oocyte was 86%. Two patients had an oocyte aspiration, which did not produce blastocysts. Thus 89% of retrievals resulted in blastocysts with an average of 3 blastocysts per patient and with 36% of fertilized oocytes becoming blastocysts. After one FET cycle, 50% of patients had a clinical pregnancy, and 38% had an ongoing or delivered pregnancy. IVM can be adapted to not disrupt a clinical IVF lab. Better treatment of oocytes during retrieval resulted in better maturity and blastocyst production.