Transient neonatal hypothyroidism due to a maternal vegan diet

Iodine is an important constituent of thyroid hormones and deficiency can lead to a range of problems depending on the degree and at what stage of life the deficiency occurs. We report a 10 day-old infant with a goitre, who presented with raised TSH on dried blood spot screening. It was observed that her mother also had a goitre. The mother was a vegan and, on dietary assessment, her iodine intake was extremely low. Both mother and infant had abnormal thyroid function tests. Mother was given Lugol's iodine and her thyroid function tests normalised. Her baby was initially prescribed thyroxine on the basis of the raised screening TSH. This was subsequently withdrawn at the age of 2 weeks, following a normal plasma TSH. Thyroid function tests remained normal and the goitre disappeared by the age of 2 months. Iodine deficiency is uncommon in the Western World. However the incidence may be rising in otherwise iodine replete areas, particularly in those who adhere to restrictive and unusual diets. In the case of pregnant mothers their unborn child's health is in danger. This report demonstrates the need to ascertain maternal diets early in antenatal care, and supplement if necessary to avoid risk to their own health and that of their offspring.     

Transient congenital hypothyroidism after amniofetography

A newborn infant who presented with goitrous congenital hypothyroidism is described. Thyroid dysfunction was due to amniofetography performed 4 days before delivery, during which a total of 5.22 g of iodine as water- and lipid-soluble contrast medium was injected. After oral l-thyroxine treatment hypothyroidism disappeared rapidly. Thyroid function remained normal when treatment was withdrawn after 28 days, underlining the transient character of hypothyroidism.     

Transient biological hypothyroidism in an infant carrier of celiac disease

This is the first report of a coeliac infant with biochemical findings of primary thyroid failure (decreased T4, decreased FT4, decreased T3, increased TSH). No clinical signs of this disorders and no thyromegaly were observed. Biochemical indices of thyroid function reverted to normal after two months on a gluten-free diet. Thyroid function impairment is suggested to be related with the active phase of coeliac disease.     

Transient congenital hypothyroidism due to maternal thyrotrophin binding inhibiting immunoglobulin

Transient congenital hypothyroidism due to maternal thyrotrophin binding inhibitor immunoglobulin (TBII), a thyroid-stimulating hormone (TSH)-receptor blocking antibody, is described in three male siblings born to a mother with autoimmune thyroiditis. These cases are believed to be the first described in Australia. The first child was found to have a serum TSH of 565 mU/L and had a negative thyroid scan when presented for neonatal screening. He was treated with thyroxine but became thyrotoxic at 3 months of age when he was on a dosage of 85 μg/m² of body surface area. He was euthyroid 6 months after discontinuation of therapy. Nine years later a second hypothyroid sibling was born, with a serum TSH of 709 mU/L on day 4. Both mother and child were demonstrated to be strongly positive for TBIl. Again this child was able to cease therapy by the age of 9 months. A third sibling, also TBIl positive, was born 12 months after the second. His TSH was 90 mU/L and his serum thyroxine (T₄) was 169 nmol/L. On this occasion, thyroid stimulation-blocking antibody was found to be present in the serum of both mother and child. Thyroxine therapy was ceased at 1 month. The family present a picture of varying degrees of transient neonatal hypothyroidism due to the transplacental passage of a maternal receptor blocking antibody. The condition is self-limiting, resolving when the immunoglobuiin is cleared from the infant's circulation.     

Effect of combined maternal and infant vitamin D supplementation on vitamin D status of exclusively breastfed infants

Severe vitamin D deficiency in mothers and their breastfed infants is a significant health problem in the Middle East. Supplementation of the breastfed infant alone with the recommended dose of vitamin D may be insufficient in high‐risk population. We investigated the effect of combined maternal and infant vitamin D supplementation on vitamin D status of the breastfed infant. We examined also the effect of supplementation on vitamin D antirachitic activity of breast milk in a subset of mothers. Healthy breastfeeding mothers (n = 90) were randomly assigned to 2000 IU daily (group 1) or 60 000 IU monthly (group 2) of vitamin D₂, and all their infants (n = 92) received 400 IU daily of vitamin D₂ for 3 months. Most infants had vitamin D deficiency – 25‐hydroxyvitamin D [25(OH)D] ≤ 37.5 nmol L^?1– at study entry. Serum 25(OH)D concentrations at 3 months increased significantly from baseline in infants of mothers in group 1 (13.9 ± 8.6 vs. 49.6 ± 18.5 nmol L^?1, P < 0.0001) and group 2 (13.7 ± 12.1 vs. 44.6 ± 15.0 nmol L^?1, P < 0.0001). Maternal and infant serum 25(OH)D concentrations correlated positively at baseline (r = 0.36, P = 0.01) and 3 months (r = 0.46, P = 0.002). Milk antirachitic activity increased from undetectable (<20 IU L^?1) to a median of 50.9 IU L^?1. In conclusion, combined maternal and infant vitamin D supplementation was associated with a threefold increase in infants’ serum 25(OH)D concentrations and a 64% reduction in the prevalence of vitamin D deficiency without causing hypervitaminosis D.     

Transient primary hypothyroidism in prematures

Twelve sick neonates, ten of whom were prematures, were found to have transient primary hypothyroidism. Two months after cessation of treatment all those followed were found to be clinically and biochemically euthyroid. The possible etiologic factors in the pathogenesis of transient hypothyroidism of the sick prematures are discussed. Iodine deficiency is probably an important precipitating cause.     

Transient congenital hypothyroidism after topical iodine in pregnancy and lactation.

A 6 week old girl with transient congenital hypothyroidism is described. The hypothyroidism was associated with multiple applications of povidone iodine during pregnancy and lactation. This case illustrates the potential hazard of using topical solutions containing iodine during pregnancy and lactation.     

Postnatal maternal cortisol levels predict temperament in healthy breastfed infants

BACKGROUND: The implications of the biologically active elements in breast milk for the breastfed infant are largely unknown. Animal models suggest that ingestion of glucocorticoids during the neonatal period influences fear behavior and modifies brain development. AIMS: To determine the association between postnatal maternal cortisol levels and temperament in breastfed infants. STUDY DESIGN: The relation between maternal cortisol and infant temperament was examined in breastfed and formula-fed infants. Plasma cortisol was used as a surrogate measure for breast milk cortisol levels (plasma and milk levels are correlated in the 0.6 to 0.7 range; [Patacchioli FR, Cigliana G, Cilumbriello A, Perrone G, Capri O, Alemà GS, et al. Maternal plasma and milk free cortisol during the first 3 days of breast-feeding following spontaneous delivery or elective cesarean section. Gynecologic and Obstetric Investigations 1992;34:159-163.]. If exposure to elevated cortisol levels during infancy influences temperament, then a relation between the two should be found among the breastfed infants, but not among the formula-fed infants. SUBJECTS: Two hundred fifty-three two-month-old infants and their mothers. OUTCOME MEASURES: Fearful temperament assessed with the Infant Behavior Questionnaire [Garstein MR, Rothbart MK. Studying infant temperament via the revised infant behavior questionnaire. Infant Behavior and Development 2003;26:64-86]. RESULTS: Among the breastfed infants, higher maternal cortisol levels were associated with reports of increased infant fear behavior (partial r=0.2; p<0.01). This relation did not exist among the formula-fed infants. Negative maternal affect at the time of assessment did not account for the positive association in the breastfed group. CONCLUSIONS: The findings are consistent with our proposal that exposure to cortisol in breast milk influences infant temperament. Biologically active components in breast milk may represent one avenue through which the mother shapes the development of the human infant during the postnatal period.