This study aimed to assess the correlation between the interleukin-10 (IL-10)-1082A/G polymorphism and idiopathic recurrent miscarriage (IRM) of Chinese Han. A total of 100 women with IRM and 100 control women with a successful pregnancy will be included in this study. Then genotyping will be performed.

As a common occurrence in early pregnancy, IRM has been associated with multiple causes, among which the disorders of immune homeostasis between the fetus and the maternal immune system, maintained by cytokines from the complex regulatory network, are considered one of the potential etiological factors underlying IRM.

The IL-10 polymorphism -1082A/G (rs1800896), which is located in the promoter region of the IL-10 gene, was reported to be implicated in the abnormal expression of IL-10 in IRM by some studies.

However, no such reports about the association between IL-10 polymorphism -1082A/G and IRM risk in Chinese Han.

Inclusion Criteria:

1. women with more than three consecutive unexplained pregnancy losses before the 20th week;
2. Chinese Han Population;
3. Patients who signed informed consent.

Exclusion Criteria:

1. Patients who had other high-risk factors which might relate with recurrent miscarriage, including: (1) Parental karyotype abnormalities: significant rearrangements (e.g. balanced translocations and mosaics) were considered abnormal. If either the patient (or her partner) had an abnormal karyotype, it was considered a parental karyotypic abnormality; (2) Genital tract abnormalities: Any congenital anatomical deformation of the genital tract was considered abnormal; intrauterine adhesions, endometriosis and hydrosalpinx were also considered abnormal; (3) alloimmune disorder; (4) Endocrine abnormalities: prolactin (PRL) level >25 ng/ml, testosterone level >2.6 nmol/L, thyroid-stimulating hormone level <0.30 mU/L or >4.5 mU/L, free thyroxine (FT4) level <8.36 nmol/L or >29.6 nmol/L and free triiodothyronine (FT3) level <1.84 nmol/L or >7.39 nmol/L. Glucose level > 126mg/dl; (5) Autoimmune disorders: Any positive results of Anti-cardiolipin antibodies (ACA-IgG/IgM/IgA), anti-nuclear antibodies (ANA-IgG), anti-endometrium antibodies (AEA-IgM), anti-ovary antibodies (AOA-IgM), anti-sperm antibodies (ASA-IgM), antithyroidin(TG-Ab), anti-thyroid peroxidase antibody(TPO-Ab) and/or anti-chorionic gonadotropin hormone antibody; (6) Hypercoagulation state: D-dimer levels >260 ng/ml, fibrin degradation products (FDP) levels >5 mg/L or anti-beta 2-glycoprotein I (anti-beta 2-GP1) levels >15 U/ml; (7) Negative RH blood groups; (8) Abnormal semen routine results of patients husband.
2. Patients with serious diseases;
3. Patients with administration of contraceptive pills;
4. Patients participated in other randomized clinical research;
5. Patients could not be followed-up of a long time or had poor compliance;
6. Patients with other factors that would affect the study result.

Female patients who referred to the Fourth Affiliated Hospital of Guangxi Medical University or Liuzhou Maternity and Child Healthcare Hospital