Influencia del informe de laboratorio en el diagnóstico de la disfunción tiroidea en la gestante: más allá del asterisco

Introduction

Thyroid physiology undergoes adaptive changes during pregnancy, making it necessary to know the reference ranges of thyroid hormones according to gestational age for a correct interpretation, especially in subclinical thyroid disease. Laboratory information systems (LIS) have difficulty in reporting reference ranges (RR) in different pathophysiological situations. The work of the laboratory physician is important in developing and designing tools to identify these situations, and to make an appropriate interpretation of the results.

Objective

To determine whether the change in the LIS in our department and the issue of the laboratory report with the interpretation of the results, had an impact on the identification and monitoring of thyroid dysfunction in pregnant women in our area.

Material and methods

A retrospective cross-sectional study was carried out by analysing the results of all first-trimester pregnant women and those on whom thyroid tests had been requested in the following six months. The pregnant women were divided into two groups, before and after the change of the LIS.

Results

Follow-up percentages were similar in the two groups, except when TSH was abnormal for pregnant women and normal for the general population, that is, when there was no asterisk.

Conclusions

The RRs established for the normal population do not identify sub-clinical thyroid disease in pregnant women. The active intervention of the laboratory physician is essential in the evaluation of these results. In our study, more than 50% of the pregnant women with sub-clinical hypothyroidism benefited from the strategy introduced.