Longitudinal trajectories of maternal TSH in healthy pregnant women in Catalonia

Objective

Longitudinal evaluation of thyroid function throughout pregnancy in the same subject could offer precise information about its dynamics as a physiological mechanism of adaption to the requirements. In this study, we evaluated longitudinal trajectories of maternal thyroid function during pregnancy by a latent class growth analysis and explored their association with maternal-fetal outcomes.

Methods

A prospective observational study was carried out, including 414 healthy pregnant women, from the first trimester to delivery. Thyroid function and autoimmunity were measured in the three trimesters. Clinical data during pregnancy were obtained. Longitudinal mixed model techniques were performed to explore trajectories of gestational thyroid function.

Results

Three different longitudinal trajectories were obtained from maternal thyrotropin (TSH) levels: low-increasing TSH (class 1) in 86% of cases, high-increasing TSH (class 2) in 9.7%, and decreasing TSH (class 3) in 4.3%. No statistical differences in free thyroxine levels were found among the three classes. Differences in maternal age (P = 0.027) and initial maternal weight (P = 0.043) were observed among the groups. In logistic regression analysis, maternal age correlated with longitudinal trajectories. The three longitudinal classes remain when women with thyroid autoimmunity (TAI) are excluded. Multinomial logistic regression showed maternal age correlated with longitudinal trajectories independently of TAI status.

Conclusions

Three differentiated TSH trajectories were found in healthy pregnant women living in Catalonia, as previously described. No association with obstetric outcomes was observed in these different chronological thyroid pathways, but maternal age might condition the longitudinal mechanism of thyroid function regulation throughout pregnancy.

Validity and reliability of the Spanish version of the "Wijma Delivery Expectancy/Experience Questionnaire" (W-DEQ-B)

The Wijma Delivery Expectancy/Experience Questionnaire (W-DEQ-B) is an instrument that allows the experiences around fear of childbirth to be examined after the birth. It is currently the most widely used to measure different aspects related to the fear of childbirth and enables healthcare and additional assistance to women after birth to be adapted according to their needs. The objective of this study was to translate the W-DEQ-B into Spanish and analyse its reliability and validity. The study was carried out in two phases: (1) transcultural adaption of the questionnaire to Spanish and (2) a transversal study in a sample of 190 postpartum women from Sexual and Reproductive Health Clinics in the province of Barcelona (Spain). The psychometric properties were examined in terms of reliability (internal consistency and temporal stability) and construct validity (confirmatory factorial analysis [CFA] and exploratory factorial analysis [EFA]). The results of the CFA did not confirm unidimensionality of the W-DEQ-B questionnaire. The EFA suggested four very similar, but not identical, dimensions to those obtained in other studies in which the W-DEQ-B has been evaluated. Both the Cronbach's alpha and the omega coefficient were adequate for the total questionnaire and for each of the four dimensions. The results of this study confirm that the W-DEQ-B is multi-dimensional. In the Spanish version of the W-DEQ-B-Sp four dimensions have been identified that allow the experiences around fear of childbirth to be examined after the birth. The Spanish version of the WDEQ-B (WDEQ-B-Sp) is reliable and valid for the measurement of fear of childbirth in clinical practice and for use in future research.