title: Assisted reproductive technologies do not increase risk of abnormal methylation of PEG1/MEST in human early pregnancy loss.
abstract: OBJECTIVE
  To evaluate the epigenetic risk linked to assisted reproductive technology (ART) by analyzing the methylation patterns of imprinted PEG1 gene in aborted human chorionic villus.
  
  
  METHODS
  Experimental research study.
  
  
  METHODS
  Research laboratory.
  
  
  METHODS
  Four patients groups were tested: spontaneous abortion after ART (n = 44), multifetal reduction after ART (n = 22), spontaneous abortion of natural pregnancies (n = 45), and induced abortion of natural pregnancies (n = 47).
  
  
  METHODS
  Methylation patterns of PEG1 in the aborted chorionic villus were determined.
  
  
  METHODS
  The DNA methylation patterns were analyzed using pyrosequencing and bisulfite sequencing polymerase chain reaction. The percentage of methylation was compared in chorionic villus from the four experimental groups.
  
  
  RESULTS
  Regardless of conception method, the PEG1 methylation percentage in chorionic villus from spontaneous abortions was significantly higher than in villus from induced abortions and multifetal reduction. In the spontaneous abortions groups, the percent methylation of PEG1 was similar in the villus derived from ART and from natural pregnancies. The two fertilization methods (IVF and intracytoplasmic sperm injection) did not show significant differences either. However, receiver operating characteristic curve analysis revealed a significant positive correlation between PEG1 methylation percentage and rate of early spontaneous abortions.
  
  
  CONCLUSIONS
  As some studies have suggested, imprinting errors of PEG1 may contribute to spontaneous abortion, but ART procedures might not increase the occurrence of aberrant PEG1 methylation patterns.
authors.affiliation: Center for Reproductive Medicine, Department of Gynecology and Obstetrics, Nanfang Hospital, Southern Medical University, Guangzhou, People's Republic of China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Zheng
authors.forename: Xiao-Yun
authors.initials: XY
authors.lastname: Shi
authors.forename: Fang-Rong
authors.initials: FR
authors.lastname: Wu
authors.forename: Ya-Qin
authors.initials: YQ
authors.lastname: Wu
authors.forename: Le-Le
authors.initials: LL
authors.lastname: Wang
authors.forename: Shi-Ling
authors.initials: SL
authors.lastname: Chen
mesh_terms: D000028:Abortion, Induced / Q000009:adverse effects; D000022:Abortion, Spontaneous / Q000378:metabolism*; D000328:Adult; D002824:Chorionic Villi / Q000378:metabolism; D019175:DNA Methylation / Q000502:physiology*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011506:Proteins / Q000378:metabolism*; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects*; D012307:Risk Factors; D055815:Young Adult
chemical_list: D011506:Proteins; C103637:mesoderm specific transcript protein