[Comparison of the etiological constitution of two and three or more recurrent miscarriage]

Objective: To compare the etiological constitution of recurrent miscarriage (RM) between patients with consecutive two and three or more miscarriages through combining the routine examination results and embryonic karyotype. Methods: Patients with a history of two or more consecutive clinical miscarriages (≤12 weeks of gestation) consulting in the RM clinic of the First Affiliated Hospital of Sun Yat-sen University from March 2011 to January 2016 were collected. Six hundred and ninety-six with detailed history recorded, routine clinical examinations of RM and at least once embryonic karyotype were ultimately enrolled in this study. Their etiological constitution of RM were analyzed in groups of consecutive two and three or more miscarriage. The etiologies of RM in analysis consisted of women age, body mass index (BMI) , chromosome abnormalities of couples, uterine abnormalities, endocrinology abnormalities and antiphospholipid syndrome (APS) . Results: (1) Among 696 patients, the abnormal embryonic karyotypes was 60.6% (422/696) and routine RM etiologies was 32.2% (224/696) , leaving the ratio of unexplained RM was only 29.0% (202/696). (2) A total of 717 embryo karyotype were found in 696 patients, included21 cases with twice embryo karyotype results the percentage of normal embryo was 39.7% (285/717) , while abnormal ones was 60.3% (432/717). Among the types of abnormal karyotype, the most common ones (>10%) were trisomy 16 (19.2%, 83/432) , monosome X (11.3%, 49/432) and trisomy 22 (10.9%, 47/432). (3) Among the 696 RM patients, the number of two and three or more miscarriages were respectively 446 (64.1%, 446/696) and 250 (35.9%, 250/696). Comparing groups of three or more miscarriages with two miscarriages, there were significant differencein older age as well as uterine adhesion (P<0.05). But no difference was found in body mass index (BMI) , the rates of chromosome abnormalities of couples, uterine abnormalities except uterine adhesion, endocrinology abnormalities and APS (all P>0.05) between two groups. Conclusions: The abnormal embryonic karyotype is the most common cause of first-trimester RM. The etiological constitution of two and three or more recurrent miscarriages is accordant, suggesting that routine clinical examination and the embryonic karyotype should be started following two consecutive clinical early miscarriages.