Association of Thyroid Dysfunction with Preeclampsia in Third Trimester of Pregnancy

Background: Preeclampsia is one of the most significant, dangerous and intriguing unsolved problems during pregnancy period. Changes in thyroid function in normal pregnancy are well-documented but very little is known in complicated pregnancy like preeclampsia. Objective: The objective of the study was to assess and compare thyroid profile (TSH, FT3 and FT4) between preeclamptic and normal pregnant women during third trimester of pregnancy. Method: This cross-sectional comparative study was conducted in the Department of Obstetrics and Gynaecology, Rajshahi Medical College Hospital, Rajshahi from 1 December 2022 to 30 November 2023. The study was carried out on 62 pregnant women who were attending in OPD and indoor of the Department of Obstetrics and Gynaecology in their third trimester of pregnancy. These women were divided into two groups-31 pregnant women with preeclampsia were included in one group and another 31 normal pregnant women were included in another group. Result: The mean ages of the women were 26.16 ± 5.71 years and 25.13 ± 5.98 years at preeclampsia and normal pregnancy group, respectively and it was statistically non-significant (p = 0.49). Preeclamptic women had higher BMI (22.81 ± 3.72 kg/m2) than the normal pregnant women (20.89 ± 2.95 kg/m2) and it was statistically significant (p = 0.03). Majority of the women in both groups lived in rural area and it were 19 (61.30%) and 22 (71.00%) in preeclampsia and normal pregnancy group, respectively. Educational status of the women revealed that a large portion of the women in both groups received primary education and were 13 (41.90%) and 14 (45.20%) in the preeclampsia and normal pregnancy group, respectively. Unemployed women were proportionately higher in both preeclamptic, and normal pregnancy group and they were 29 (93.50%) and 28 (90.30%), respectively. Monthly family income was almost identical between the preeclamptic and normal pregnancy group (p=0.59) with mean monthly family income taka 14838.71±4879.19 and 14161.29±4933.54, respectively. Primigravid 20 (64.50%) women were proportionately higher in preeclamptic group but multigravida 17 (54.80%) women were proportionately higher in normal pregnancy group and it was statistically non-significant (0.13). No significant difference was also observed between the preeclamptic and normal pregnancy group with respect to gestational age (p=0.55) and mean gestational ages were 32.77±3.34 weeks and 33.26±2.10 weeks, respectively. Preeclamptic women had proportionately more above the normal range of TSH 21 (67.70%) but below the normal range of both FT3 14 (45.20%) and FT4 19 (61.30%) in comparison to healthy pregnant women who had proportionately higher, normal range of both TSH 26 (83.30%), FT3 24 (77.40%) and FT4 22 (71.00%). Conclusion: Preeclamptic women had significantly higher level of TSH but lower level of serum FT3 and FT4 in comparison to normal pregnant women in third trimester. Hypothyroidism might be a modifiable risk factor for preeclampsia and thyroid screening early in pregnancy might be helpful in predicting the occurrence of preeclampsia. Though estimation of serum thyroid function tests is simple, reliable, economic and sensitive, timely thyroid hormone administration could reduce the maternal and perinatal morbidity and mortality associated with preeclampsia.