title: No increase in renal iodine excretion during pregnancy: a telling comparison between pregnant women and their spouses.
abstract: OBJECTIVE
  Adequate dietary iodine intake is necessary for normal thyroid gland function at all times, and most particularly during pregnancy. Increased iodine loss is cited, among other factors, as responsible for the increased iodine demand in this period. Our aim was to compare renal iodine excretion between women during all three pregnancy trimesters with that of their spouses and thereby to estimate the iodine intake in an a large sample of pregnant women in urban areas in Greece.
  
  
  METHODS
  Four hundred twenty-four healthy pregnant women were included prospectively (residents of Athens n=218, residents of Patras n=206). The spouses of 177 of these women following the same diet were also studied. Determinations included serum FT4, TSH and aTPO and urinary iodine excretion (UIE).
  
  
  RESULTS
  No difference was found either in median UIE throughout pregnancy or between the UIE of the pregnant women and their spouses during the trimesters. Throughout pregnancy, mild iodine deficiency was noted and was classified as mild in 60%, moderate in 30% and severe in 10% of the women studied. Users of iodized salt had significantly higher median UIE compared with non-users. Serum FT4 levels decreased and TSH increased as pregnancy progressed.
  
  
  CONCLUSIONS
  Our study indicates that renal iodine excretion is not increased during pregnancy. This finding needs to be confirmed by further investigation in other populations with different iodine intakes. Thus, increased iodine requirements in pregnancy are possibly due to extra-renal causes. The population of pregnant women in Greek urban areas is mildly-and often moderately and severely-iodopenic and needs to be treated accordingly.
authors: Department of Endocrinology, "Elena Venizelou" Hospital, Athens, Greece.
authors: Eftychia
authors: E
authors: Koukkou
authors: Department of Obstetrics and Gynecology, University of Patras; Greece.
authors: Stavros
authors: S
authors: Kravaritis
authors: Department of Endocrinology, University of Patras; Greece.
authors: Irene
authors: I
authors: Mamali
authors: Department of Obstetrics and Gynecology, University of Patras; Greece.
authors: Georgios G
authors: GG
authors: Markantes
authors: Department of Endocrinology, University of Patras; Greece.
authors: Marina
authors: M
authors: Michalaki
authors: Department of Obstetrics and Gynecology, University of Patras; Greece.
authors: Georgios G
authors: GG
authors: Adonakis
authors: Department of Obstetrics and Gynecology, Department of Endocrinology, University of Patras; Greece.
authors: Neoklis A
authors: NA
authors: Georgopoulos
authors: Department of Endocrinology, University of Patras; Greece.
authors: Kostas B
authors: KB
authors: Markou
mesh_terms: D000328:Adult; D003677:Deficiency Diseases / Q000097:blood / Q000188:drug therapy / Q000652:urine; D004032:Diet; D019587:Dietary Supplements; D005260:Female; D006115:Greece; D006801:Humans; D007455:Iodine / Q000172:deficiency / Q000652:urine*; D007668:Kidney / Q000378:metabolism*; D008297:Male; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000188:drug therapy / Q000652:urine; D011264:Pregnancy Trimesters / Q000097:blood / Q000652:urine; D011446:Prospective Studies; D065667:Renal Elimination; D018454:Spouses; D013961:Thyroid Gland / Q000378:metabolism*; D013963:Thyroid Hormones / Q000097:blood; D014504:Urban Health; D055815:Young Adult
chemical_list: D013963:Thyroid Hormones; D007455:Iodine