Introduction: The new guidelines for the management of hypothyroidism (HP) during pregnancy recommend a tighter treatment with levothyroxine (Lt4) to reach TSH values similar to those of pregnant women without thyroid dysfunction (TSH <2.5 mU/l in the 1st trimester-T- and TSH <3mu/l in the 2nd and 3rd T).
Objectives: To assess the degree of control of HP in women followed during pregnancy according to the current criteria and the possible association between control of TSH in each T and: miscarriage%, preterm deliveries% and few gestational complications frecuencies (pregnancy induced hypertension-HTA-, gestational diabetes-GD-) and birth weight.
Patients and methods: Study of 217 pregnant women with primary HP followed in our hospital for Lt4 adjustment.We describe miscarriage %, preterm deliveries%;few gestacional complications% and birth weight.
Results: 23.2% of women did not take a minimum 150 μg daily iodine supplements in their first assessment. % of women with TSH <4.3 mU/l (normal superior reference range -NSR-in non-pregnant population) changed from 78.7% before pregnancy to 64.8% in the 1st T, 84.8% in the 2nd T and 95.1% in 3rdT (P <0.05). % of pregnant women with TSH < NSR for pregnant population was significantly lower: 31.3%, 63.9% and 86.8% in the 1st, 2nd and 3rd T respectively. This % was higher in those patients submitted earlier (1st T:76%) than late (in 3rd T: 91%, P <0.05). There were no significant differences in preterm deliveries %, HTA, GD comparing women with TSH values within the control goals to those with TSH above goals in any trimesters. We found a non significant trend toward greater % of preterm deliveries with high TSH values in 2 nd T. Mothers% whose newborns weighed <2300 g was higher in those with 3erT TSH> 4.3 mU/l vs TSH ≤ 4.3 (20 vs 2.7%, P=0.04) and with TSH 3erT> 3 vs <3 mUi /l (11.5 vs. 2.3%, P=0.05).
Conclusion: Early assesment of pregnant women is necessary to achieve goals of control (possibly in the preconceptional period). The high level of controlled patients% in 3erT could explain the lack of significant differences in the% of complications.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector
05 - 09 May 2012
European Society of Endocrinology