Intrauterine diagnosis and treatment of fetal goitrous hypothyroidism

Higher frequency of Congenital Hypothyroidism among Newborns, District Dera Ghazi Khan-Punjab, Pakistan: A case control study

OBJECTIVES

The study objective was to establish serum TSH cut off value for diagnosis of new case of congenital hypothyroidism and to estimate frequency of Congenital Neonatal Hypothyroidism.

METHODS

A case control study was conducted at DHQ Teaching Hospital of DG Khan Medical College, Dera Ghazi Khan during 2020 to establish reference values of TSH and T4 for study population. Sample size was calculated by classical sample size calculation formula Cochran WG 1977 sampling technique. A group of 30 neonates of normal, healthy, euthyroid mothers was taken as Neonatal Control Group to estimate levels of TSH and total T4 in normal neonates. Neonatal Study Group was neonates of hypothyroid mothers (n=75). Simple random sampling technique was applied.

RESULTS

Mean (mean ± SD) Serum TSH levels of Neonatal Control Group were found to be 3.58 ± 03.09 mIU/l. Mean Serum TSH levels among Neonatal Study Group were found to be 6.88 ±12.95 mIU/l and serum total T4 were found to be 16.78 ± 6.96ug/dl on 3-7 days of life. Serum total T4 (mean ± SD) levels of Neonatal Control Group were 9.73 ± 03.39 ug/dl. Neonatal serum TSH more than 15mIU/l was taken as cut off value to diagnose a case of CNH. So, frequency of CNH was 8% among neonates of study group.

CONCLUSIONS

The TSH cut off value of >15mIU/l was established for case detection of CNH. Our findings of CNH in district Dera Ghazi Khan (8%) are the highest frequency of CNH reported so far in Pakistan.

Intra-amniotic levothyroxine infusions in a case of fetal goiter due to novel Thyroglobulin gene variants

Indications and administration of intra-amniotic infusions of L-thyroxine in the context of non-immune fetal hypothyroidism with goiter lack of standardization. Systematic follow-up of clinical features related to thyroid hormonal homeostasis may be useful to evaluate their efficiency and develop standardized management guidelines.

Conservative in utero treatment of fetal dyshormonogenetic goiter with levothyroxine, a systematic literature review

Fetal goitrous hypothyroidism is a rare condition associated with important obstetrical, neonatal complications, and neurodevelopmental impairments. Prenatal treatment remains controversial, and the risk to benefit ratio must be accurately assessed and considered for individualized management. The objective of this review was to evaluate the feasibility, safety, and effectiveness of the conservative in utero treatment of fetal goitrous hypothyroidism. In total, 25 reports that met our inclusion criteria were selected and the management of 38 cases was analyzed. Prenatal diagnosis consisted mainly of ultrasonographic findings. Fetal thyroid status was assessed by cordocentesis. Prenatal treatment varied widely in terms of levothyroxine (LT4) route of administration, dosage, number of injections, and frequency. Although different regimens and routes of administration were proposed, they seem to have similar results regarding fetal goiter reduction and thyroid status at birth. At birth, most babies had hypothyroidism, but the long-term follow-up indicated a normal psycho-neuromotor development. Our data confirm the feasibility of conservative treatment with LT4 for fetal goitrous hypothyroidism. Further studies are needed to determine the optimal management of this disorder.

Impaired Gene Expression Due to Iodine Excess in the Development and Differentiation of Endoderm and Thyroid Is Associated with Epigenetic Changes

Background: Thyroid hormone (TH) synthesis is essential for the control of development, growth, and metabolism in vertebrates and depends on a sufficient dietary iodine intake. Importantly, both iodine deficiency and iodine excess (IE) impair TH synthesis, causing serious health problems especially during fetal/neonatal development. While it is known that IE disrupts thyroid function by inhibiting thyroid gene expression, its effects on thyroid development are less clear. Accordingly, this study sought to investigate the effects of IE during the embryonic development/differentiation of endoderm and the thyroid gland. Methods: We used the murine embryonic stem (ES) cell model of in vitro directed differentiation to assess the impact of IE on the generation of endoderm and thyroid cells. Additionally, we subjected endoderm and thyroid explants obtained during early gestation to IE and evaluated gene and protein expression of endodermal markers in both models. Results: ES cells were successfully differentiated into endoderm cells and, subsequently, into thyrocytes expressing the specific thyroid markers Tshr, Slc5a5, Tpo, and Tg. IE exposure decreased the messenger RNA (mRNA) levels of the main endoderm markers Afp, Crcx4, Foxa1, Foxa2, and Sox17 in both ES cell-derived endoderm cells and embryonic explants. Interestingly, IE also decreased the expression of the main thyroid markers in ES cell-derived thyrocytes and thyroid explants. Finally, we demonstrate that DNA methyltransferase expression was increased by exposure to IE, and this was accompanied by hypermethylation and hypoacetylation of histone H3, pointing to an association between the gene repression triggered by IE and the observed epigenetic changes. Conclusions: These data establish that IE treatment is deleterious for embryonic endoderm and thyroid gene expression.

Thyroid hormone therapy in congenital hypothyroidism and pediatric hypothyroidism

The evaluation and management of hypothyroidism in children are similar to adults, but there are important differences based on the dependence on normal thyroid function for neurocognitive and physical development. In the pediatric population, hypothyroidism is frequently categorized as congenital or acquired hypothyroidism, depending on the age of presentation and the underlying etiology. The evaluation and management of children and adolescents with hypothyroidism are determined by the etiology as well as by the age at diagnosis, severity of the hypothyroidism, and the response to thyroid hormone replacement therapy. Children and adolescents require higher weight-based doses for thyroid hormone replacement than do adults, likely due to a shorter half-life of thyroxine (T4) and triiodothyronine (T3) in children, but weight-based dose requirements decrease as the child advances into adulthood. Multiple gaps in knowledge remains regarding how to optimize the treatment of hypothyroidism in pediatric patients, including (but not limited to) the selection of patients with subclinical hypothyroidism for treatment, and the potential benefit of combined LT3/LT4 therapy for patients with persistent symptoms and/or low T3 on LT4 monotherapy. The life-long impact on growth and development, and potentially on long-term cardiovascular and psychosocial health, are significant and highlight the importance of future prospective studies in pediatric patients to explore these areas of uncertainty.

Graves' disease complicated by fetal goitrous hypothyroidism treated with intra-amniotic administration of levothyroxine

Fetal goitrous hypothyroidism is a rare entity and is caused mainly by maternal treatment of Graves' disease (GD). We report a case of a 22-year-old woman referred at 12 weeks of gestation due to hyperthyroidism subsequent to recently diagnosed GD. She started treatment with propylthiouracil and, at 21 weeks of gestation, fetal goitre was detected. A cordocentesis confirmed the diagnosis of fetal goitrous hypothyroidism, and intra-amniotic administration of levothyroxine (LT4) was performed and repeated through the pregnancy due to maintenance of fetal goitre. The pregnancy proceeded without further complications and a healthy female infant was born at 37 weeks of gestation, with visible goitre and thyroid function within the normal range at birth. Although there is no consensus on the optimal dose, the number of injections and the interval between them, intra-amniotic LT4 administration is recommended once fetal goitrous hypothyroidism is suspected, in order to prevent long-term complications of fetal hypothyroidism.

Iodine-Induced Fetal Hypothyroidism: Diagnosis and Treatment with Intra-Amniotic Levothyroxine

BACKGROUND

Iodine is necessary for fetal thyroid development. Excess maternal intake of iodine can cause fetal hypothyroidism due to the inability to escape from the Wolff-Chaikoff effect in utero.

CASE REPORT

We report a case of fetal hypothyroid goiter secondary to inadvertent excess maternal iodine ingestion from infertility supplements. The fetus was successfully treated with intra-amniotic levothyroxine injections. Serial fetal blood sampling confirmed fetal escape from the Wolff-Chaikoff effect in the mid third trimester. Early hearing test and neurodevelopmental milestones were normal.

CONCLUSION

Intra-amniotic treatment of fetal hypothyroidism may decrease the rate of impaired neurodevelopment and sensorineural hearing loss.

Fetal goiter conservatively monitored during the prenatal period associated with maternal and neonatal euthyroid status

Congenital goiter is considered a rare occurrence, and may be related to hypothyroidism, hyperthyroidism, or euthyroidism. In this report, we describe a case of fetal goiter identified in the 34th gestational week in a 41-year-old secundigravida with normal thyroid functions. A conservative approach was followed; the fetal goiter was monitored via ultrasound, which suggested this was a case of hyperthyroidism. After the birth, tests indicated that the newborn was euthyroidic. Consequently, a more detailed study using non-invasive procedures was deemed necessary to discover the precise cause of the fetal goiter during the gestational period.

Antenatal diagnosis and treatment of hypothyroid fetal goiter in an euthyroid mother: a case report and review of literature

Fetal goiter is an extremely rare complication of pregnancy. Its incidence is 1 in 40,000 deliveries. Antithyroid maternal therapy is responsible for 10-15% of fetal congenital hypothyroidism and can be considered as the most frequent underlying cause for this condition. The frequency of fetal goiter that is associated with fetal hypothyroidism and normal maternal thyroid function, as in our case, is even less frequent. Fetal goiter is associated with increased rate of perinatal complications and long-term morbidity, due to peripartum complications including labor dystocia due to its mass effect, as well as neonatal airway obstruction that may lead to hypoxic-ischemic brain injury and death. We present, in this study, a case report of late antenatal fetal goiter in an euthyroid woman and a literature review of the diagnosis and treatment of these cases.

Fetal blood sampling

OBJECTIVE

We sought to review indications, technical aspects, risks, and recommendations for fetal blood sampling (FBS).

METHODS

A systematic review was performed using MEDLINE, PubMed, EMBASE, and Cochrane Library using the terms "fetal blood sampling," "percutaneous umbilical blood sampling," and "cordocentesis." The search was restricted to English-language articles published from 1966 through July 2012. Priority was given to articles reporting original research, in particular randomized controlled trials, although review articles and commentaries also were consulted. Abstracts of research presented at symposia and scientific conferences were not considered adequate for inclusion in this document. Evidence reports and guidelines published by organizations or institutions such as the National Institutes of Health, Agency for Health Research and Quality, American Congress of Obstetricians and Gynecologists, and Society for Maternal-Fetal Medicine were also reviewed, and additional studies were located by reviewing bibliographies of identified articles. Grade (Grading of Recommendations Assessment, Development, and Evaluation) methodology was employed for defining strength of recommendations and rating quality of evidence. Consistent with US Preventive Task Force guidelines, references were evaluated for quality based on the highest level of evidence.

RESULTS AND RECOMMENDATIONS

Ultrasound-guided FBS is the only procedure that provides direct access to the fetal circulation. When invasive testing is planned for suspected severe fetal anemia or thrombocytopenia, we recommend FBS as the procedure of choice, with availability of immediate transfusion if confirmed. We recommend against the use of FBS for indications in which other less invasive, and therefore lower risk, alternatives are available. The overall success rate of FBS is high, and blood samples can be obtained in >98% of patients. We suggest that counseling for FBS include discussion about the potential risk of FBS that may include, but may not be limited to: bleeding from puncture site (20-30%); fetal bradycardia (5-10%); pregnancy loss (≥1.3%, depending on indication, gestational age, and placental penetration); and vertical transmission of hepatitis or human immunodeficiency virus. We recommend that FBS be performed by experienced operators at centers with expertise in invasive fetal procedures when feasible.