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Changes in osmolality and blood serum ion concentrations in pregnancy

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Changes in osmolality and the concentration of cations (Na, K, Ca, Mg) were studied in blood serum of pregnant women from two weeks after conception, throughout the whole pregnancy, and within the first week after delivery. Altogether 239 women from 18 to 40 years of age were studied. Blood serum osmolality decreased from 287±0.8 to 278±1.6 mOsm/kg H2O from the fifth week of pregnancy and remained virtually at this level until the end of pregnancy. Hyponatremia was found during the three trimesters of pregnancy, in trimesters II and III hypokalemia was not observed, whereas hypocalcemia and hypomagnemia were found. On the first day after delivery, the blood serum osmolality and concentrations of magnesium ions returned to their levels in nonpregnant women, whereas concentrations of sodium and calcium ions remained decreased. No correlation was found between hypoosmia and changes in blood serum concentrations of ions under study during the three trimesters of pregnancy. Thus, in normal pregnancy, hypoosmia develops from the fifth week after conception and persists until delivery. The concentrations of sodium, potassium, calcium, and magnesium ions are regulated by independent mechanisms to provide retention of these parameters within certain periods of pregnancy at the level of nonpregnant women on the background of hypoosmia.

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References

  1. Davison, J.M., Edema in Pregnancy,Kidney Int., 1997, vol. 59, p. S90.

    Google Scholar 

  2. Katz, A.I. and Lindheimer, M.D., Kidney Disease and Hypertension in Pregnancy, inTextbook of Nephrology, Massry, S.G. and Glassock, R.J., Eds., Baltimore: Williams, Wilkins, 1995, vol. 2, p. 1148.

    Google Scholar 

  3. Davison, J.M., Sheills, E.A., Philips, P.R., and Lindheimer, M.D., Serial Evaluation of Vasopressin Release and Thirst in Human Pregnancy. Role of Human Horionic Gonadotrophin in the Osmoregulatory Changes of Gestation.J. Clin. Invest., 1988, vol. 8, no. 3, p. 798.

    Google Scholar 

  4. Davison, J.M., Sheills, E.A., Philips, P.R.,et al., Influence of Humoral and Volume Factors Altered Osmoregulation of Normal Human Pregnancy,Am. J. Physiol., vol. 258, no. 4, part 2, p. F900.

  5. Davison J.M., Sheills, E.A., Philips, P.R.,et al., Metabolic Clearance of Vasopressin and Analogue Resistant to Vasopressinase in Human Pregnancy,Am. J. Physiol., 1993, vol. 264, no. 2, part 2, p. F348.

    PubMed  CAS  Google Scholar 

  6. Serov, V.N., Strizhakov, A.N., and Markin, S.A.,Prakticheskoe akusherstvo. Rukovodstvo dlya vrachei (Practical Obstetrics. Guidebook for Physicians), Moscow: Meditsina, 1989.

    Google Scholar 

  7. Ekeke, G.I. and Ebirim, U.A., Serum Sodium and Potassium Values in Pregnant Urban Nigerian and Caucasian Women,Trop. Georg. Med., 1986, vol. 38, no. 1, p. 28.

    CAS  Google Scholar 

  8. Ekeke, G.I., Nduka, N., and Rukaki, A., Serum Calcium and Protein Levels in Pregnant African and Caucasian Women,Trop. Georg. Med., 1985, vol. 37, no. 2, p. 178.

    CAS  Google Scholar 

  9. Fiziologiya vodno-solevogo obmena i pochki (Physiology of Water-Salt Metabolism and Kidneys), Natochin, Yu. V., Ed., St. Petersburg: Nauka, 1993.

    Google Scholar 

  10. Entsiklopediya klinicheskikh laboratornykh testov (Encyclopedia of Clinical Laboratory Tests), Tits, N.U., Ed., Moscow: Labinform, 1997.

    Google Scholar 

  11. Natochin, Yu. V.,Pochka. Spravochnik vracha (Kidney. Reference Book for Physician), St. Petersburg: Petersburg Gos. Univ., 1997.

    Google Scholar 

  12. Robertson, G.L., Athar, S., and Shelton, R.L., Osmotic Control of Vasopressin Function, inDisturbances in Body Fluid Osmolality, Andreoli, T.E., Grantham, J.J., and Rector, F.C., Jr., Eds., Am. Physiol. Soc. Bethesda, 1977.

  13. Lindheimer, M.D. and Davison, J.M., Osmoregulation, the Secretion of Arginine, Vasopressin, and Its Metabolism during Pregnancy,Eur. J. Endocrinol., 1995, vol. 132, no. 2, p. 133.

    Article  PubMed  CAS  Google Scholar 

  14. Johnson, M.R., Brooks, A.A., and Steer, P.J., The Role of Relaxin in the Pregnancy Associated Reduction in Plasma Osmolality,Hum. Reprod., 1996, vol. 11, no. 5, p. 1105.

    PubMed  CAS  Google Scholar 

  15. Stachenfeld, N.S., DiPietro, L., Palter, S.F., and Nadel, E.R., Estrogen Influences Osmotic Secretion of AVP and Body Water Balance in Postmenopausal Women,Am. J. Physiol., 1998, vol. 274, no. 1, part 2, p. R187.

    PubMed  CAS  Google Scholar 

  16. Ohara, M., Martin, P.Y., Xu, D.L.,et al., Upregulation of Aquaporin 2 Water Channel Expression in Pregnant Rats,J. Clin. Invest., 1998, vol. 101, no. 5, p. 1076.

    PubMed  CAS  Google Scholar 

  17. Pitkin, R.M., Calcium Metabolism in Pregnancy and the Perinatal Period: A Review,Am. J. Obstet. Gynecol., 1985, vol. 151, no. 1, p. 99.

    PubMed  CAS  Google Scholar 

  18. Pitkin R.M., and Gebhardt, M.P., Serum Calcium Concentration in Human Pregnancy,Am. J. Obstet. Gynecol., 1977, vol. 127, no. 7, p. 775.

    PubMed  CAS  Google Scholar 

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Authors and Affiliations

  1. Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, pr. Morisa Toreza 44, 194223, St. Petersburg, Russia

    E. I. Shakhmatova

  2. St. Petersburg State University, Universitetskaya nab. 7/a, 199164, St. Petersburg, Russia

    N. A. Osipova & Yu. V. Natochin

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  1. E. I. Shakhmatova
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  2. N. A. Osipova
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  3. Yu. V. Natochin
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Shakhmatova, E.I., Osipova, N.A. & Natochin, Y.V. Changes in osmolality and blood serum ion concentrations in pregnancy. Hum Physiol 26, 92–95 (2000). https://doi.org/10.1007/BF02760724

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