title: Molecular cytogenetic analysis of early spontaneous abortions conceived from varying assisted reproductive technology procedures.
abstract: BACKGROUND
  Spontaneous abortion (SA) is the most common complication of pregnancy, and chromosome aberrations are the principal cause of the first trimester abortuses in natural conception (NC) The increasing use of assisted reproductive technology (ART) has raised concern about chromosome abnormalities in ART-initiated pregnancies. Up to date, the literature on the risk of aneuploidy in failed pregnancies among various ART factors remain limited and inconclusive. This study aimed to explore the genetic etiology of pregnancy loss conceived from varying ART procedures.
  
  
  RESULTS
  A total of 560 cases of villus that were successfully collected and performed molecular karyotype analysis were enrolled in present research, including 92 cases of NC, 340 cases of in-vitro fertilization (IVF) and 128 cases of intracytoplasmic sperm injection (ICSI). There was no statistical difference in the distribution of karyotyping results and the aneuploidy rate of each individual chromosome among NC, IVF and ICSI group. Both the total chromosomal abnormality rate and the one chromosome aneuploidy rate were increased with maternal age. Compared with fresh ET abortion group, frozen-thawed embryo transfer (FET) abortion group had elder maternal age (34.68 ± 4.73 years vs. 33.41 ± 4.48 years,P= 0.003) but lower chromosomal aberration rate of abortus (58.33 % vs. 67.50 %,P= 0.040). A slightly higher incidence of chromosome segmental abnormalities was found in FET than in fresh ET abortion (5.26 % vs. 2.08 %,P= 0.066).
  
  
  CONCLUSIONS
  Chromosomal abnormality of fetus is the main cause of SA in the first trimester, no matter pregnancies are conceived through NC, IVF or ICSI. ART is a relatively safety treatment, and it does not enhance aneuploidy rate of abortus. The FET is bad for ongonging pregnancy and the aneuploidy rate were increased with maternal age.
authors.affiliation: Shenzhen Key Laboratory for Reproductive Immunology of Preimplantation, Shenzhen Zhongshan Institute for Reproduction and Genetics, Fertility Center, Shenzhen Zhongshan Urology Hospital, No. 1001 Fuqiang Road, Futian District, Shenzhen, 518045 China.
authors.forename: Tonghua
authors.initials: T
authors.lastname: Wu
authors.affiliation: The State Key Laboratory of Medical Genetics of China, Central South University, No. 110 Xiangya Road, Kaifu District, Changsha, 410013 China.
authors.forename: Biao
authors.initials: B
authors.lastname: Yin
authors.affiliation: Shenzhen Key Laboratory for Reproductive Immunology of Preimplantation, Shenzhen Zhongshan Institute for Reproduction and Genetics, Fertility Center, Shenzhen Zhongshan Urology Hospital, No. 1001 Fuqiang Road, Futian District, Shenzhen, 518045 China.
authors.forename: Yuanchang
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Shenzhen Key Laboratory for Reproductive Immunology of Preimplantation, Shenzhen Zhongshan Institute for Reproduction and Genetics, Fertility Center, Shenzhen Zhongshan Urology Hospital, No. 1001 Fuqiang Road, Futian District, Shenzhen, 518045 China.
authors.forename: Guangui
authors.initials: G
authors.lastname: Li
authors.affiliation: Shenzhen Key Laboratory for Reproductive Immunology of Preimplantation, Shenzhen Zhongshan Institute for Reproduction and Genetics, Fertility Center, Shenzhen Zhongshan Urology Hospital, No. 1001 Fuqiang Road, Futian District, Shenzhen, 518045 China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Ye
authors.affiliation: Shenzhen Key Laboratory for Reproductive Immunology of Preimplantation, Shenzhen Zhongshan Institute for Reproduction and Genetics, Fertility Center, Shenzhen Zhongshan Urology Hospital, No. 1001 Fuqiang Road, Futian District, Shenzhen, 518045 China.
authors.forename: Chunmei
authors.initials: C
authors.lastname: Chen
authors.affiliation: Shenzhen Key Laboratory for Reproductive Immunology of Preimplantation, Shenzhen Zhongshan Institute for Reproduction and Genetics, Fertility Center, Shenzhen Zhongshan Urology Hospital, No. 1001 Fuqiang Road, Futian District, Shenzhen, 518045 China.
authors.forename: Yong
authors.identifier: 0000-0002-1385-3518
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: The State Key Laboratory of Medical Genetics of China, Central South University, No. 110 Xiangya Road, Kaifu District, Changsha, 410013 China.
authors.forename: Desheng
authors.initials: D
authors.lastname: Liang
keywords: ART; Aneuploidy; FET; Maternal age; Spontaneous abortion