Intravaginal embryo culture: more than just a novelty?

Abstract

Intravaginal culture (IVC) devices offer a novel assisted reproductive technology (ART) treatment option at a significantly reduced cost from traditional in-vitro fertilization (IVF) cycles. This study aimed to assess the efficacy of the INVOcell (INVO Bioscience) intravaginal culture device with day 5 blastocyst transfers in our center compared with intrauterine insemination (IUI) cycles. Retrospective study. Patients were initially informed that IVC had unknown success rates in our clinic prior to starting their cycle. These cycles were offered at a discounted cost. Patient were only offered IVC as a potential treatment option if they met the following criteria: normal semen analysis, normal uterine cavity, anti-mullerian hormone value of 1 - 6 ng/mL, follicular stimulating hormone value of <10 mIU/mL, estradiol level <60 pg/mL, no previous IVF cycle failures, and no plastic allergies or history of toxic shock. Following oocyte retrieval, cumulus oocyte complexes were trimmed and inseminated for 5 minutes before being placed in an IVC device loaded with pre-equilibrated continuous culture media overlaid with mineral oil. The device was inserted into the patient’s vagina for incubation and carried for 5 days before she returned to have embryo development evaluated and an embryo transfer. IUI’s were performed with gradient prepared semen per standard protocols. Data was collected for a single calendar year in 2017. A total of 36 patients, between ages 27 and 42, opted to have IVC cycles performed. All patients were able to tolerate the device well, with no adverse events requiring premature removal of the device. The per-start positive biochemical pregnancy rate was 52% and the ultrasound confirmed pregnancy rate was 47%. The per-transfer pregnancy rates were 69% and 63% respectively with a total of 28 transfers performed (a 22% non-transfer rate). The pregnancy rates for IUI performed in the same calendar year were 13% and 12% respectively for patients in the same age bracket with a total of 869 cycles performed. IVC with day 5 blastocyst transfers appears to offer an appreciable pregnancy rate increase when compared with IUI cycles. While IVC cannot compete with full IVF cycles, due to inherent treatment limitations, it may offer a more efficacious first treatment option for infertility patients that meet the selection criteria than several rounds of IUIs. However, despite success for a large percentage of patients, we observed a high non-transfer rate of 22% due to either no fertilization or poor embryo progression. Although disappointing, these patients can now progress to full IVF cycles sooner than if they had continued with IUI cycles as IVC cycles offer more diagnostic value than IUIs. More research is needed to understand if IVC can effectively, in terms of cost and patient success, be added to most center’s treatment repertoires and become an additional standard of care.