SERUM RELAXIN, SYMPHYSEAL PAIN, AND BACK PAIN DURING PREGNANCY

OBJECTIVE: Our purpose was to study the relationship between serum rel axin levels and back pain during pregnancy. STUDY DESIGN: A prospectiv e clinical cohort study with repeated examinations was performed. RESU LTS: There was an initial increase of relaxin levels until a peak valu e at the twelfth week followed by a decline until the seventeenth week . Thereafter stable serum levels around 50% of the peak value were rec orded. Three months after delivery serum relaxin was not detectable. T here was a significant correlation between mean serum relaxin levels d uring the pregnancy and symphyseal pain or low back pain occurring dur ing late pregnancy as measured by medical history or pain-provoking te st. CONCLUSION: Relaxin is known to remodel pelvic connective tissue i n several mammalian species during pregnancy. The current data suggest that relaxin might be involved in the development of pelvic pain in p regnant women.