Effect .of oral contraceptives
on serum protein
Utilizing the technique of single radial immunodiffusion, the concentrations of 8 serum proteins have been measured in women using various oral contraceptives. A significant decrease in albumin concentration and significant increases in concentrations of IgM, ceruloQlasmin, and a,-antitrypsin were noted. Similar but more marked changes were noted in the sera of Qregnant women at term. Unlike the marked increase in concentration of transferrin observed during pregnancy, no significant alteration in the transferrin level was noted in women using oral contraceptives.
T H E E X T E N s I v E metabolic alterations produced by high levels of circulating ovarian steroids are most clearly manifested in pregnancy. In addition to the changesin salt and water metabolism and the obvious morphologic changesin reproductive tract tissues accompanying heightened protein anabolism, alterations in the concentrations of several serum proteins have been d0cumented.l Following administration of estrogens to nonpregnant individuals, changes in serum protein patterns simiiar to those observed in pregnant patients have been detected by several investigators.2*s They also observed an increasein the concentration of someproteins, a decrease in the concentration of others, and no change in the level of many. In some instances the effect appears dependent upon both the dosageof steroid and the length of time of administration.4 The significance and implications of these changes is poorly understood at present. Use of oral contraceptives has been de-
From the Department Gynecology, University College of Medicine.
of Obstetrics of Florida
scribed as producing a “metabolic pseudopregnancy.“6 In the present study, the effect of oral contraceptive usageon the concentrations of 8 serum proteins has been investigated. The values determined are contrasted with those seen in the pregnant patient at term. Materials
Eight separate proteins representative of the major electrophoretic fractions of serum have been measured by the technique of single radial immunodiffusion. Venous blood was drawn from 20 healthy women in the reproductive age group, at different stagesin the menstrual cycle, who were receiving a variety of sequential and combination-type oral contraceptives including Ortho-Novum (norethindrone 2 mg. and mestranol 0.1 mg. ) , Enovid-E (norethynodrel 5 mg. and mestranol 0.075 mg.) , Ovulen (ethynodiol diacetate 1 mg. and mestranol 0.1 mg.) , Norinyl (norethindrone 2 mg. and mestranol 0.1 mg.) , and Oracon (ethinyl estradiol 0.1 mg. alone or with 25 mg. dimethisterone) for periods ranging from 2 months to 7 years. Antigens and antisera were prepared, and serum protein concentrations were measured as previously described.l The control group consisted of 25 healthy women in the reproductive age period. The levels of albumin,
This work was supported in part by the 1967 National Institutes of Health General Research SUQQ~ Grcmt No. 5501~FR-05362-07 at the University of Florida College of Medicine.
Table I. Serum protein concentrations
Albumin (w. %)
4,296 + 451
3,800+463 < 0.001
1,1652291 > 0.4
(mean values + 1 SD.) Cerulo-
Nonpregnant women Oral contraceptives P values’
892 28 241 ? 142 114?46 < 0.05 meam
201?100 > 0.2 to chance
t test of
100 802 17
Table II. Comparison of serum protein concentrations in pregnancy (at term) and in women using oral contraceptives
Pregnant women Oral contraceDtives
trypsin (%) 324 2 90
2422 146 234267
IgG, IgM, and IgA were measured in the serum of each of these women and for ceruloplasmin, transferrin, cuz-macroglobulin, and cyl-antitrypsin a pool of their sera was chosen as a normal reference serum.
cul-antitrypsin noted above in the women taking oral contraceptives also occurs in pregnancy but to a more marked degree. The principle difference in the 2 groups studied is that transferrin is markedly increasedin concentration during pregnancy.
In Table I, the mean concentrations of the 8 proteins measured in the sera of women receiving oral contraceptives are contrasted with the values detected in the control sera. Whereas a significant lowering of the concentration of albumin occurs in the serum of women receiving oral contraceptives, a significant increase in the concentration of IgM, ceruloplasmin, and cu,-antitrypsin can be detected. The levels of IgG, IgA, transferrin, and cyz-macroglobulin are similar in the 2 series. In Table II, the concentrations of the various proteins found at term in the pregnant woman are contrasted with those detected following the use of oral contraceptives. The decreasein albumin concentration and the increase in IgM, ceruloplasmin, and
The increasing use of ovarian steroids as an effective and readily accepted contraceptive has quite properly stimulated investigation into their effect on normal physiology. Numerous studies have suggesteda similarity to the metabolic alterations detected in normal pregnancy, and in most instances, estrogen rather than any particular progestagen appears to be responsible for the changes produced. Data obtained by Doe, Muss, and Seal374 indicate a significant elevation in serum ceruloplasmin following estrogen administration which is dose dependent. They also detected an increase in P-glucuronidase, thyroxine-binding globulin, plasminogen, corticosteroid-binding globulin, and 17-hydroxycorticosteroid levels but no
changes in sialic acid, transferrin, or haptoglobin levels. Robertson,G examining the sera of women taking oral contraceptives with electrophoretic and scanning techniques, noted decreased albumin concentrations and serum cholinesterase levels but increased (Yeglobulin concentrations. In the present study, a significant decrease in serum albumin concentration was detected in women using oral contraceptives as well as an increase in the concentration of ceruloplasmin and of 01~antitrypsin, the principal al-globulin in the serum, thus confirming the work of Seal and Robertson. The more marked changes seen in pregnancy at term suggest a dosagedependency effect, although this phenomenon was not specifically examined in our work. The lack of rise in transferrin concentration following estrogen administration seen in the present study and noted by others3 is of particular interest in view of the report by Burton’ that serum total ironbinding capacity is strikingly elevated in the presence of normal transferrin saturation in a group of women using oral contraceptives. Our knowledge as to the mechanism of production of these alterations is incomplete and controversial. While estrogen has been reported to produce a degree of hemodilution,8, 9 Robertson’s failure to detect hematocrit changes in his study group and the albumin kinetics studies of Hsngerl”, I1 suggest that estrogen depresses albumin levels by yet another mechanism. The possibility that a direct effect on hepatic metabolism occurs following estrogen administration stimulated numerous investigations productive of conflicting data. Swyer and Little12 concluded that there was no evidence of hepatic damage in women taking oral contraceptives for as long as 6 years, while Larsson-CohnI detected abnormal retention of BSP (sulfobromophthalein) in 42 per cent of patients studied. Eisalo, J&vinen, and Luukkainenl”
1. Mendenhall, H. GYNEC. Accepted
W. : for
March J. Obstet.
1, 1970 Gynec.
also noted abnormal BSP retention in 48 per cent of women receiving a particular oral contraceptive, but among two groups of patients receiving preparations containing a lesser amount of estrogen, no abnormalities were detected. In an investigation of hepatic metabolism of two commonly used anesthetic adjuncts, pethidine and promazine, a diminution in the ability to metabolize these drugs was noted following estrogen and progesterone administration.15 The concern over possible alterations in blood coagulation mechanisms with a subsequent predisposition to intravascular clotting following the administration of oral contraceptives, has stimulated numerous laboratory investigations, again with the production of conflicting conclusions. An increase in Factor VII and Factor X has been reported,16 alto detect any though Tyler5 was unable changes which could be interpreted as demonstrating an increased tendency to spontaneous intravascular clotting. Studies on carbohydrate and lipid metabolisml’* l8 in patients receiving oral contraceptives have demonstrated a significant percentage of patients as having changes resembling those seen in steroid diabetes. The possibility exists, therefore, that these multiple changes in the concentrations of serum proteins are merely a reflection of altered rates of anabolism and catabolism, and are not indicative of cellular damage. To dismiss the production of these alterations as harmless, however, when continued over the many years encompassing the reproductive period in a woman’s life, is open to question. The final judgment awaits the acquisition of additional knowledge about the basic action of ovarian steroids. The author wishes to acknowledge the excellent technical assistance of Mrs. Julia Deere.
2. Doe, R. P.: Mellinger, G. T., Swain, W. R., and Seal, U. S.: J. Clin. Endocr. 27: 1081, 1967.
3. 4. 5. 6. 7. 8. 9. 10. Il.
Musa, B. U., Doe, R. P., and Seal, U. S.: J. Clin. Endocr. 27: 1463. 1967. Muss, B. U., Seal, U.‘S., and Doe, R. P.: J. Clin. Endocr. 25: 1163, 1965. Tyler, E. T.: Brit. Med. J. 2: 843, 1964. Robertson. G. S.: Lancet 1: 232. 1967. Burton, J: L.: Lancet 1: 978, 1967. Witten, C. L., and Bradbury, J. T.: Proc. Sot. Exp. Biol. Med. 78: 626, 1951. Preedy, J. R. K., and Aitken, E. H.: J. Clin. Invest. 35: 423, 1956. Hanger, P. E.: Stand. J. Clin. Lab. Invest. 19: 238, 1967. Hanger, P. E.: Stand. J. Clin. Lab. Invest. 20: 3, 1967.
12. 13. 14. 15. 16. 17. 18.
Swyer, G. I. M., and Little, V.: Brit. Med. J. 1: 1412, 1965. Larsson-Cohn, U.: Brit. Med. J. 1: 1414, 1965. Eisalo, A., Jarvinen, P. A., and Luukkainen, T.: Brit. Med. J. 1: 1416, 1965. Crawford, J. S., and Rudofsky, S.: Brit. .J. Anaesth. -38: 446, 1966. Poller. L.. and Thomson. T. M.: Brit. Med. J. 2: 23, 1966. ’ ” Wynn, V., and Doar, .J. W. H.: Lancet 2: 715, i966: Wynn, V., and Doar, J. W. H.: Lancet 2: 720, 1966.