Ultrasonographic Evaluation of Changes in Thyroid Volume In Women During Pregnancy and Lactation

Abstract

Objectives: Thyroid gland volume may vary physiologically during pregnancy and lactation. We aimed to determine ultrasonographic changes in thyroid volume in this study. Materials and Methods:The thyroid ultrasound in 30 mothers was performed at the 9th months of gestation, and also 6th and 12th months after delivery, to calculate thyroid volume.The volume of each lobe was estimated in cubic centimeters using the equation of Brunn et al. The volume of each thyroid gland was obtained by collecting the volume of the right and left lobes. The data were analyzed using SPSS, version 15.0 package program. Results:The mean volume of the thyroid gland in women in the control group was 11.95 ± 1.90mL. When compared with the control group, a significant increase in thyroid gland volume was seen in the third trimester. Decrease at the sixth month after delivery was not significant. But the decline in the values in the twelfth month was statistically significant. Conclusion:Knowing the limits of this physiological increase will be important in distinguishing it from other possible pathologies. We think that the mean thyroid volume values we find will be useful in daily clinical practice.

References values and predictive factors for thyroid volume in pregnant women

“…The trend toward increased thyroid size after 24 gestational weeks in the present study is consistent with the findings of other studies (7,8). Around the third trimester, there is a peak in serum estrogen concentrations, with an increase in the vasculature of the uterus and placenta.…”

“…Changes in thyroid physiology are also reflected in the growth of the gland to meet the hormonal demands of the mother and the fetus. According to some reports, during pregnancy, the thyroid significantly increases in volume, while other researchers observed slight or no growth; these differences are largely due to the genetic and environmental factors of each population, especially iodine intake (6)(7)(8)(9). Reports of gland volume in pregnant women from different regions describe means between 8 and 12 mL (7,8,10,11).…”

“…Investigations of the thyroid volume of pregnant women are scarce, and their conclusions are heterogeneous (7,8,12). In Cuba, a National Program was established in 2002 to ensure the mandatory iodization of salt for human consumption.…”

Correlation between Sonographic Findings of Maternal Thyroid Gland and Thyroid Function Tests during Pregnancy

“…During pregnancy, the thyroid function tests changes mainly due to the effect of two hormones i.e. estrogen and human chorionic gonadotropin (hCG) [5]. The most remarkable changes occur in pregnancy which induces maternal thyroid gland to adapt appropriately.…”