Serum relaxin, symphyseal pain, and back pain during pregnancy


      OBJECTIVE: Our purpose was to study the relationship between serum relaxin levels and back pain during pregnancy. STUDY DESIGN: A prospective clinical cohort study with repeated examinations was performed. RESULTS: There was an initial increase of relaxin levels until a peak value at the twelfth week followed by a decline until the seventeenth week. Thereafter stable serum levels around 50% of the peak value were recorded. Three months after delivery serum relaxin was not detectable. There was a significant correlation between mean serum relaxin levels during the pregnancy and symphyseal pain or low back pain occurring during late pregnancy as measured by medical history or pain-provoking test. CONCLUSION: Relaxin is known to remodel pelvic connective tissue in several mammalian species during pregnancy. The current data suggest that relaxin might be involved in the development of pelvic pain in pregnant women. (Am J Obstet Gynecol 1996;175:1342-7.)


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        • Kristiansson P
        • Svärdsudd K
        • von Schoultz B.
        Back pain during pregnancy: a prospective study.
        Spine. 1996; 21: 702-709
        • Östgaard HC.
        Back pain and pregnancy.
        ([thesis]) University of Göteborg, Göteborg, Sweden1991
        • Biering-Sorensen F
        Low back trouble in a general population of 30-, 40-, 50-, and 60-year-old men and women: study design, representativeness and basic results.
        Dan Med Bull. 1982; 29: 289-299
        • Abramson D
        • Roberts SM
        • Wilson PD
        Relaxation of the pelvic joints in pregnancy.
        Surg Gynecol Obstet. 1934; 58: 595-613
        • Putschar WGJ
        The structure of the human symphysis pubis with special consideration of parturition and its sequelae.
        Am J Physiol Anthropol. 1976; 45: 589-594
        • Houghton P
        The bony imprint of pregnancy.
        Bull N Y Acad Med. 1975; 51: 655-661
        • Kristiansson P
        • Svärdsudd K.
        Discriminatory power of tests applied in back pain during pregnancy.
        Spine. 1996 (in press)
        • Wahl LM
        • Blandau RJ
        • Page RC
        Effect of hormones on collagen metabolism and collagenase activity in the pubic symphysis ligament of the guinea pig.
        Endocrinology. 1977; 100: 571-579
        • Stewart DR
        • Celniker AC
        • Taylor CA
        • Craigin JR
        • Overstreet JW
        • Lasley BL
        Relaxin in the peri-implantation period.
        J Clin Endocrinol Metab. 1990; 70: 1771-1773
        • Johnson MR
        • Abbas AA
        • Allman AC
        • Nicolaides KH
        The regulation of plasma relaxin levels during human pregnancy.
        J Endocrinol. 1994; 142: 261-265
        • Johnson MR
        • Wren ME
        • Abdalla H
        • Kirkland A
        • Allman AC
        • Lightman SL
        Relaxin levels in ovum donation pregnancies.
        Fertil Steril. 1991; 56: 59-61
        • Ljubica VB
        • Morton M
        • Bryant-Greenwood GD
        Relaxin gene expression in human reproductive tissues by in situ hybridization.
        J Clin Endocrinol Metab. 1995; 80: 130-136
        • Bryant-Greenwood GD
        • Bogic L
        • Maaskant R
        • Qin X
        • Yamamoto S
        • Greenwood FC
        Decidual relaxin and the human fetal membranes.
        in: Progress in relaxin research, 1994. Global Publications, Singapore1994
        • MacLennan AH
        • Nicolson R
        • Green RC
        • Bath M
        Serum relaxin and pelvic pain of pregnancy.
        Lancet. 1986; 2: 243-245
        • Petersen LK
        • Hvidman L
        • Uldbjerg N
        Normal serum relaxin in women with disabling pelvic pain during pregnancy.
        Gynecol Obstet Invest. 1994; 38: 21-23
        • Mooney V
        • Cairns D
        • Robertson J
        A system for evaluating and treating chronic back disability.
        West J Med. 1976; 124: 370-376
        • Lucas C
        • Bald LN
        • Martin MC
        • Jaffe RB
        • Drolet DW
        • Mora-Worms M
        • et al.
        An enzyme-linked immunosorbent assay to study human relaxin in human pregnancy and in pregnant rhesus monkeys.
        J Endocrinol. 1989; 120: 449-457
        • Steinetz BG
        • O'Byrne EM
        • Butler MC
        • Hickman LB
        Hormonal regulation of the connective tissue of the symphysis pubis.
        in: Biology of relaxin and its role in the human. Excerpta Medica, Amsterdam1984: 71-92
        • Schwabe C
        • Steinetz B
        • Weiss G
        • Segaloff A
        • McDonald K
        • O'Byrne E
        • et al.
        Rec Prog Horm Res. 1978; 34: 123-213
        • Crelin ES
        The development of the bony pelvis and its changes during pregnancy and parturition.
        Trans N Y Acad Sci. 1969; 31: 1049-1058
        • MacLennan AH
        • Green RC
        • Grant P
        • Nicolson R
        Ripening of the human cervix and induction of labor with intracervical purified porcine relaxin.
        Obstet Gynecol. 1986; 68: 598-601
      1. Progress in relaxin research, 1994. Global Publications, Singapore1994