Endocrine Abstracts

Introduction: Fetal goiter is a rare condition. The incidence of goitrous hypothyroidism is 1/30 000–50 000 live births. We describe a case of antenatal fetal goiter that vanished upon delivery and was not detected in the newborn. The case report is followed by a discussion wherein we review the literature on thyroid problems in pregnancy and management of fetal goiter.

Case report: A 27-year-old known hypothyroid woman with bichorial biamniotic pregnancy had antenatal ultrasound (USG) at 24 weeks of gestation and found to have a butterfly shaped, uniformly echogenic and highly vascular solid mass on the anterior aspect of fetal neck of one twin. Polyhydramnios and other complications were absent. Thyroid swelling was confirmed on fetal MRI. The other twin was normal. Color Doppler indicated hypofunction of thyroid which was confirmed with cordocentesis. Mother was hypothyroid with very high anti TPO antibody titre. The case was managed by titrating maternal thyroxin and serial monitoring of fetal thyroid size and function. Patient delivered preterm at 30 weeks of gestation. There was no thyroid swelling in any of the twins which was confirmed on USG. Both babies were euthyroid at birth had normal development on follow up so far.

Conclusion: Fetal goiter results in compression of the esophagus and the trachea and leading to polyhydramnios, hyperextension of the neck and dystocia during labor and mental and motor retardation later in life. Therefore, diagnosis of fetal hypothyroidism should be established at an early stage and appropriate hormone replacement treatment should be started. Fetal thyroid color Doppler is a new modality that helps in determining fetal thyroid function and can help to avoid invasive procedures like cordocentesis in appropriate cases. We emphasize on importance of noninvasive USG and maternal biochemical monitoring and correction as required. Hence, a strategic approach to fetal goiter is required to achieve optimal benefits at minimal fetal and maternal risk.

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.