Embryo transfer and luteal support in natural cycles

Abstract

Embryo transfer policy and luteal supplementation was reviewed, comparing literature data and the results from the Maribor IVF Centre. A retrospective analysis of 1024 cycles in patients undergoing IVF, intracytoplasmic sperm injection (ICSI) or testicular sperm aspiration in unstimulated cycles was carried out using four different approaches for cycle monitoring. This showed that the most successful protocol for monitoring was administration of human chorionic gonadotrophin (HCG) when serum oestradiol was >0.49 nmol/l and follicle diameter was at least 15 mm. The implantation rate per transferred embryo was higher when a blastocyst was transferred (42.8%) rather than a day-2 embryo (23.5%) in the same monitoring protocol. Analysis of the influence of patient age on the success of oocyte retrieval, oocyte fertilization, embryo transfer rate and delivery rate demonstrates that patient age does not influence the rate of positive oocyte retrieval or fertilization rate as much as it influences pregnancy rate per embryo transfer. The delivery rate per cycle was dramatically influenced by age in patients over 38 years. There is no clear evidence in the literature as to whether luteal phase support is necessary in natural cycles for IVF/ICSI. Comparing the data, a higher pregnancy rate was observed if HCG was administered after embryo transfer.

Recurrent implantation failure: current update and clinical approach to an ongoing challenge

“…Of the pregnancies that are lost, 75% represent a failure of implantation and are therefore not clinically recognized as pregnancies (1). The pregnancy rate per cycle is even lower when in vitro fertilization (IVF) is employed in a natural cycle (2).…”

Combination of IVF and IVM in naturally cycling women

“…No delivery rate was reported. A retrospective analysis of 1024 oocyte retrievals in natural cycles showed a delivery rate per oocyte retrieval of 6.9% (Vlaisavljevic, 2007).…”

“…However, in natural-cycle IVF treatment, a number of other problems arise, including spontaneous ovulation or an increased risk of no oocytes being retrieved during oocyte retrieval and no embryos available for transfer. This means that the cancellation rate is high, between 20% and 30% (Pelinck et al, 2002;Vlaisavljevic, 2007).…”

Morphokinetic Characteristics and Developmental Potential of In Vitro Cultured Embryos from Natural Cycles in Patients with Poor Ovarian Response

“…Embryo transfer was performed on day 3 of cultivation. The luteal phase was supported by administration of 2500 IU of hCG on the day of transfer [22]. Serological pregnancy was tested for 16 days later and was positive if serum β -hCG was more than 10 IU/mL.…”