Single embryo transfer (SET) is a technique used in assisted reproductive treatment (ART) that is used to promote singleton pregnancies. To date, there are five reported cases of dizygotic twin pregnancies with mothers who underwent SET. Here, we present a sixth case of a dichorionic, diamniotic twin pregnancy with sex discordance. The patient is a 34-year-old woman with unexplained secondary infertility who underwent in vitro fertilization (IVF) and frozen-thawed embryo transfer from a SET. The ultrasonographic images from the first and second trimester scans identified dichorionic, diamniotic twin gestations. The delivery was full term and postnatal genetic testing confirmed 46, XX, and 46, XY offspring. Pathology reports of the placental and membrane findings reported diamniotic, dichorionic twins. There was no zygosity testing conducted, thus it is unknown if the twins are monozygotic or dizygotic. Two possible etiologies for sex-discordant twins, in this case, are concurrent natural conception via breakthrough ovulation at the time of SET, or discordant postzygotic nondisjunction of a single embryo. Multiple gestations may still occur in the setting of SET and zygosity testing in these instances would better elucidate our understanding of this occurrence. Moreover, improved data on the zygosity of multiple gestations following SET may enhance patient counseling.

A retrospective cohort study was conducted comparing conventional intracytoplasmic sperm injection (ICSI) with a pre-catching sperm (PCS)-ICSI technique. Cases with at least 0.5 million motile sperm and 5 mature oocytes were included. Conventional ICSI involves simultaneous loading of sperm and oocytes onto the dish, followed by identification, immobilization, and loading of sperm into pipettes for oocyte injection. In the PCS-ICSI technique, suitable sperm were identified and immobilized prior to oocyte loading onto the dish, thus reducing the oocyte exposure time. Variables of interest included rate of fertilized and degenerated oocytes, abnormal fertilization, quality blastocyst formation, and pregnancy outcomes. Statistical analysis utilized Student’s t-test and Fisher’s Exact Test. Our study included 330 PCS-ICSI and 287 conventional ICSI cases. Female age, BMI, AMH, total number of collected oocytes, and rate of abnormal fertilization were similar between groups. The PCS-ICSI group demonstrated an increased rate of oocyte fertilization (84.0% vs. 79.3%, p < 0.001), good quality blastocyst formation (54.9% vs. 48.0%, p < 0.001), and a lower rate of oocyte degeneration (1.4% vs. 3.5%, p < 0.001). Positive pregnancy rate, clinical pregnancy, and live birth rate were similar between groups. The expansion of this technique resulted in increased oocyte fertilization and good quality blastocyst formation, and decreased oocyte degeneration. Further studies will evaluate the effectiveness of this technique in broader patient populations.

Background/Objectives: Efficient sperm separation is critical for Assisted Reproductive Technology (ART). This study evaluates how assisted liquefaction (AL), a faster sperm preparation technique, affects motile sperm recovery and ART outcomes. Methods: A prospective pair analysis to address the efficiency of AL and retrospective cohort analysis of IUI and IVF/ICSI cycles were performed. Results: The average time to perform AL was 3 min, in comparison to the 15 to 30 min for traditional liquefaction (TL) until initiating sperm preparation. The total motility (p = 0.252) and progressive motility (p = 0.227) of the sperm samples were about 4% higher in the AL group although there was no significant difference. No significant differences were observed between AL and TL in fertilization (80.0% vs. 81.9%, p = 0.297), blastocyst rates (48.2% vs. 48.1%, p = 0.595), positive pregnancy (70.5% vs. 75.0%, p = 0.667), clinical pregnancy (65.9% vs. 68.4%, p = 0.841), or live birth (52.3% vs. 51.3%, p = 0.831) outcomes in IVF. The Positive pregnancy (p = 0.669) and clinical pregnancy (p = 0.841) of IUI were not significantly different between both groups. Conclusions: AL offers similar results to TL while reducing preparation time without interrupting ART outcomes. AL may have benefit to asthenozoospermia cases for ART due to reduced exposure time of sperm to semen that may prevent sperm quality impact.