Embryonic development in human oocytes fertilized by split insemination

Abstract

ObjectiveTo compare the laboratory outcomes of intracytoplasmic sperm injection (ICSI) and conventional insemination using sibling oocytes in poor prognosis IVF cycles where ICSI is not indicated.MethodsCouples undergoing IVF with following conditions were enrolled: history of more than 3 years of unexplained infertility, history of ≥3 failed intrauterine insemination, leukocytospermia or wide variation in semen analysis, poor oocyte quality, or ≥50% of embryos had poor quality in previous IVF cycle(s). Couples with severe male factor requiring ICSI were excluded. Oocytes were randomly assigned to the conventional insemination (conventional group) or ICSI (ICSI group). Fertilization rate (FR), total fertilization failure, and embryonic development at day 3 and day 5 were assessed.ResultsA total of 309 mature oocytes from 37 IVF cycles (32 couples) were obtained: 161 were assigned to conventional group and 148 to ICSI group. FR was significantly higher in the ICSI group compared to the conventional group (90.5% vs. 72.7%, P<0.001). Total fertilization failure occurred in only one cycle in conventional group. On day 3, the percentage of cleavage stage embryos was higher in ICSI group however the difference was marginally significant (P=0.055). In 11 cycles in which day 5 culture was attempted, the percentage of blastocyst (per cleaved embryo) was significantly higher in the ICSI group than the conventional group (55.9% vs. 25.9%, P=0.029).ConclusionHigher FR and more blastocyst could be achieved by ICSI in specific circumstances. Fertilization method can be tailored accordingly to improve IVF outcomes.

More blastocysts are produced from fewer oocytes in ICSI compared to IVF – results from a sibling oocytes study and definition of a new key performance indicator

“…In concordance with our results analyzed in their globality and by sub-groups, previous authors applying split insemination found significant higher fertilization rate in ICSI compared to IVF [11,[15][16][17]28], comparable cleavage rate [10-12, 14, 15, 20], no statistical difference in blastocyst rate [11,13], comparable implantation [10,12] and live birth rates [13,16].…”

“…Previous authors applying split insemination reported data from embryo development until cleavage stage [ 10 , 12 , 15 , 16 ] or on a minor number of cases [ 11 , 13 , 14 , 18 , 28 ]. The present study is the first one focused mainly on blastocyst stage, and on such a high number of cases that could also be analyzed according to different clinical parameters.…”

Comparison of clinical outcomes between in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in IVF-ICSI split insemination cycles

“…In split insemination cycles, the fertilization rate has been reported to be somewhat different between IVF and ICSI in multiple studies. In many studies, the fertilization rate of ICSI was reported to be higher than that of IVF when the fertilization rates were calculated based on the oocytes allocated to IVF or ICSI [ 19 20 21 22 ]. However, it has been reported that the fertilization rate of IVF was similar to or higher than that of ICSI in several studies [ 6 17 23 ].…”

“…The results of fertilization after split insemination can then be helpful for determining the insemination method (IVF or ICSI) in subsequent cycles. Split insemination has mainly been implemented in patients with unexplained infertility or mild male factor infertility, and the clinical outcomes of IVF and ICSI have been compared in split insemination cycles [ 12 13 14 15 16 17 18 19 ]. However, the effectiveness of split insemination remains controversial.…”