RESUMEN
Objective To observe the change of umbilical artery S/D value in the third trimester pregnant women with overt hypothyroidism(OH) or subclinical hypothyroidism(SCH).Methods We collect the data of 37-42 weeks pregnancy from January 2014 to December 2015.We devided them into OH group,SCH group and contral group.We compared the umbilical artery S/D value in these three groups and analyzed the relativity between S/D value and thyroid hormone.Results The S/D value was 2.46 ± 0.31 in OH group,2.48 ± 0.27 in SCH group and 2.32 ± 0.17 in control group.The differences were statistically significant between OH group and contral group (P =0.000),SCH group and contral group (P =0.000).There was no statistically significant between OH group and SCH group (P =0.907).The proportion of cases number during different S/D value range in these three groups had difference (P =0.000).The S/D value was positively correlated to TSH in OH group (r =0.186,P =0.037) and SCH group (r =0.146,P =0.015).There was no correlation between FT3 and S/D value(P ＞ 0.05) or FT4 and S/D value(P ＞ 0.05) in both OH and SCH group.There was no correlation between thyroid hormone and S/D value in the contral group either.Conclusion Both OH and SCH can effect umbilical artery S/D value in the third trimester pregnancy.