title: Decreased Sperm Motility Retarded ICSI Fertilization Rate in Severe Oligozoospermia but Good-Quality Embryo Transfer Had Achieved the Prospective Clinical Outcomes.
abstract: BACKGROUND
  Spermatozoa motility is the critical parameter to affect the treatment outcomes during assisted reproductive technologies (ART), but its reproductive capability remains a little informed in condition of severe male factor infertility. This retrospective cohort study aimed to evaluate the effects of reduced sperm motility on the embryological and clinical outcomes in intra-cytoplasmic sperm injection (ICSI) treatment of severe oligozoospermia.
  
  
  METHODS
  966 cycles (812 couples) of severe oligozoospermia diagnosed by spermatozoa count ≤ 5 × 106/mL and motile spermatozoa ≤ 2 × 106/mL were divided into four groups in according to the number of motile spermatozoa in one ejaculate on the day of oocyte retrieval (Group B-E). The control (Group A) was 188 cycles of moderate oligozoospermia with spermatozoa count > 5 × 106/mL and motile spermatozoa > 2 × 106/mL. All female partners were younger than 35 years of age. Logistic regression analyzed embryological outcomes (the rates of fertilization, cleavage and good-quality embryo) and clinical outcomes (the rates of pregnancy, implantation, early miscarriage and live birth). Quality of embryo transfer (ET) was divided into three classes as continuous factor to test the effects of embryo quality on clinical outcomes.
  
  
  RESULTS
  The reduction in the number of motile sperm in four groups of severe oligozoospermia gave rise to comparable inability of the fertilization (p < 0.001) and a decreased rate of good-quality embryo at Day 3 (p < 0.001) by compared to the control. The cleavage rate of the derived zygotes was similar to the control. ET classes significantly affected the clinical outcomes (p < 0.001). Class I ET gave rise to similar rates of clinical outcomes between five groups, but Class II and Class III ET retarded the rates of pregnancy, implantation and live birth and this particularly occurred in Group C, D and E. The rate of early miscarriage was not comparably different between groups. Overall rates in all groups were 41.26% clinical pregnancy, 25.74% implantation and 36.32% live birth, which gave live birth to 252 girls and 252 boys.
  
  
  CONCLUSIONS
  The reduction of motile spermatozoa in severe oligozoospermia decreased the rates of fertilization and good-quality embryo. Obtaining and transfer of good-quality embryos was the good prognostic to achieve prospective clinical outcomes regardless of the severity of oligozoospermia.
authors.affiliation: Key Laboratory of Contraceptive Drugs and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai, China.|Department of Reproductive Medicine, Renji Hospital, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Jufeng
authors.initials: J
authors.lastname: Zheng
authors.affiliation: Department of Reproductive Medicine, Renji Hospital, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Yongning
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Reproductive Health Center, the Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Xianqin
authors.initials: X
authors.lastname: Qu
authors.affiliation: Key Laboratory of Contraceptive Drugs and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Reproductive Medicine, Renji Hospital, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Luiwen
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Reproductive Medicine, Renji Hospital, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Minzhi
authors.initials: M
authors.lastname: Gao
authors.affiliation: Key Laboratory of Contraceptive Drugs and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai, China.|Shanghai Key Laboratory of Reproductive Medicine, Shanghai Jiaotong University Medical School, Shanghai, China.
authors.forename: Huijuan
authors.initials: H
authors.lastname: Shi
authors.affiliation: Sydney Center for Regenerative and Developmental Medicine, Kolling Institute for Medical Research, Sydney Medical School, University of Sydney, St. Leonards, NSW, Australia.|Reproductive Health Center, the Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
authors.forename: Xingliang
authors.initials: X
authors.lastname: Jin