[Serum relaxin in cervical incompetence patients]

To analyze the serum relaxin and clinical character of cervical incompetence patients and normal pregnant women.

A total of 33 cervical incompetence patients (research group) and 33 normal pregnancy women with the same gestational age (control group) were recruited into the study. The serum relaxin level was detected with enzyme labeled immunosorbent assay (ELSIA) in the two groups, and the cervical length of early pregnancy period (cm), body mass index (BMI, kg/m2), frequency of polycystic ovary syndrome (%), gestational diabetes mellitus/diabetes mellitus (%) and outcomes in the two groups were analyzed with independent samples t test and chi-square test.

All the cervical incompetence patients were recruited between Feb. 2008 and Sept. 2012, with the average termination gestational age of 30±6 weeks. Among them, 15 (45.45%) was abortion, 12 (36.36%) was preterm birth, 6 (16.18%) was term birth. The average BMI before pregnancy was 27±4 kg/m2, and the average serum relaxin was 2,748±82 mg/L; for the 33 patients in the control group, the average termination gestational age was 38±3 weeks, and 1 (3.03%) of them was abortion, 4 (12.12%) was preterm birth, 28 (84.85%) was term birth. The average BMI before pregnancy was 23±3 kg/m2, the average serum relaxin was 2,602±126 mg/L. Compared with the control group, the research group had more patients who complicated with polycystic ovary syndrome and gestational diabetes mellitus/diabetes mellitus (P<0.01, <0.05) and worse pregnancy outcomes (P<0.01); the average BMI before pregnancy and the average serum relaxin level of the research group were significantly higher than control group (P<0.01, P<0.01). Analysis through the unconditional logistic regression showed that BMI and serum relaxin were both independent risk factors of cervical incompetence.

The high level of serum relaxin is an independent risk factor of cervical incompetence; women with polycystic ovary syndrome may more likely to have cervical incompetence and serum relaxin may have the predictive value for cervical incompetence.