en Gynecology & Obstetrics Gynecology & Obstetrics Original Research Original Research <font face="Times New Roman" size="3"> </font><p class="MsoNormal" style="margin: 0in 0in 10pt text-align: justify text-justify: inter-ideograph"><font size="3"><font face="Calibri"><b><span style="line-height: 115% mso-bidi-font-size: 9.0pt">Background:</span></b><span style="line-height: 115% mso-bidi-font-size: 9.0pt"> To investigate thyroid function in preeclamptic patients in comparison with normal pregnant women.<o:p /></span></font></font></p><font face="Times New Roman" size="3"> </font><p class="MsoNormal" style="margin: 0in 0in 10pt text-align: justify text-justify: inter-ideograph"><font size="3"><font face="Calibri"><b><span style="line-height: 115% mso-bidi-font-size: 9.0pt">Methods:</span></b><span style="line-height: 115% mso-bidi-font-size: 9.0pt"> In this analytical cross-sectional study free Thyroxine (T4), and Thyroid Stimulating Hormone (TSH) levels were measured in 100 preeclamptic patients and were compared with Free T4 and TSH levels in 101 normal pregnant women in their third trimester of pregnancy. Patients with thyroid or other systemic disorders were excluded from this study.<o:p /></span></font></font></p><font face="Times New Roman" size="3"> </font><p class="MsoNormal" style="margin: 0in 0in 10pt text-align: justify text-justify: inter-ideograph"><font size="3"><font face="Calibri"><b><span style="line-height: 115% mso-bidi-font-size: 9.0pt">Results:</span></b><span style="line-height: 115% mso-bidi-font-size: 9.0pt"> A significant difference in concentration of free T4 levels (0.729 ±0.324 ng/ dl versus 0.929± 0.314 ng/dl, p <0.001) was observed in the preeclamptic group compared with the normotensive group, but the mean TSH level was not significantly different (2.935±1.16 mIU/L versus 2.339±1/15 mIU/L, p = 0.170).<o:p /></span></font></font></p><font face="Times New Roman" size="3"> </font><p class="MsoNormal" style="margin: 0in 0in 10pt text-align: justify text-justify: inter-ideograph"><font size="3"><font face="Calibri"><b><span style="line-height: 115% mso-bidi-font-size: 9.0pt">Conclusion:</span></b><span style="line-height: 115% mso-bidi-font-size: 9.0pt"> Women who develop preeclampsia are more likely to have lower normal limits of thyroid function during their final weeks of pregnancy.<o:p /></span></font></font></p><font face="Times New Roman" size="3"> </font> Thyroxin, Hypothyroidism, Preeclampsia, Thyroid stimulating hormone. 1 5 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-606&slc_lang=en&sid=1 Zahra Raoofi drzraoofi@yahoo.com 200319475328460017439 200319475328460017439 Yes Department of Obstetrics and Gynecology, Iran University of Medical Sciences, Tehran, Iran. Anahita Jalilian dr_anahita547@yahoo.com 200319475328460017440 200319475328460017440 No Department of Obstetrics and Gynecology, Ilam University of Medical Sciences, Ilam, Iran. Mansorah Shabani Zanjani mansourahshabanizanjani@yahoo.com 200319475328460017441 200319475328460017441 No Department of Obstetrics and Gynecology, Iran University of Medical Sciences, Tehran, Iran. Seyedeh Paniz Parvar panizprvr@yahoo.com 200319475328460017442 200319475328460017442 No Kerman University of Medical Sciences, Kerman, Iran. Seyedeh Pegah Parvar pegahprvr@rocketmail.com 200319475328460017443 200319475328460017443 No Azad University of Medical Sciences, Tehran, Iran.