Purpose To report our experience of fertility preservation (FP) in female cancer patients. Materials and Methods We retrospectively analyzed the medical records of female who underwent elective oocyte or embryo cryopreservation before cancer treatment between January 2015 and December 2020 at Asan Medical Center. We analyzed the type of cancer, the rate of reuse of cryopreserved oocytes or embryos, and fertility outcomes such as the resumption of menstruation or pregnancy. Results A total of 174 patients underwent 182 oocyte retrieval cycles after controlled ovarian stimulation for oocyte or embryo cryopreservation. The median age of patients was 33.0 (range 19–46) years, and the patients were most unmarried female (65.52%). The majority of patients were diagnosed with breast cancer (78.16%), and the remaining were diagnosed with gastrointestinal (6.33%) and hematologic malignancies (5.75%). The maturation rate of oocyte cryopreservation was 83.33%, and the fertilization rate of embryo cryopreservation was 72.07%. Of the 57 patients currently not undergoing cancer treatment, 34 resumed menstruating and 19 (33.33%, 19/57) returned to attempt a pregnancy. Among them, five patients succeeded in natural pregnancy. Eleven patients received frozen-thawed embryo transfer, and four patients succeeded in becoming pregnant (36.36%, 4/11). Only 6.3% of patients returned to use their gametes, and 93.7% of gametes are still in storage. Conclusion FP in cancer patients should be considered before cancer treatment. Through continuous research on oncofertility, it is necessary to consider how to increase the return rate and provide appropriate information to cancer patients of reproductive age.

Background To assess the clinical efficacy of intravenous immunoglobulin G (IVIG) administration combined with low-dose aspirin in women with unexplained recurrent pregnancy loss (RPL). Methods We retrospectively analyzed the medical records of patients who had been diagnosed with unexplained RPL and treated with IVIG and low-dose aspirin between January 2000 and March 2020 at Asan Medical Center. We analyzed pregnancy outcomes and their association with the percentage of natural killer (NK) cells. Results The study analyzed a total of 93 patients and 113 natural and assisted reproductive technology pregnancy cycles. The live birth rate per cycle was 73.5% (83/113), and the term delivery rate was 86.7% (72/83). The live birth rate was high regardless of the type of RPL, method of pregnancy, timing of IVIG treatment, and presence or absence of autoantibodies. In addition, the live birth rate was significantly higher in patients who received IVIG more than once, compared with patients who received IVIG only once (77.8% vs. 42.9%, P = 0.006). There was no significant association between the NK cell counts and live birth rate (65.5% in the group with NK cell < 12%, and 69.7% in that with NK cell ≥ 12%, P = 0.725). Among all patients, 87.6% had no complications, and there were no congenital malformation among newborn babies. Conclusion IVIG combined with low-dose aspirin treatment showed favorable pregnancy outcomes regardless of the patient’s NK cell counts (%).