Hypothyroidism is rarely included in the differential diagnosis for fetal sinus bradycardia. We report an infant with congenital hypothyroidism caused by ectopic thyroid tissue, who showed antenatal bradycardia. The baseline fetal heart rate was 100-110 bpm at 30 weeks of gestation, and fetal echocardiography revealed sinus bradycardia but no cardiac anomalies. Maternal thyroid function was normal (thyroidstimulating hormone [TSH] 2.03 μIU/ml, free T3 2.65 pg/ml, and free T4 0.99 ng/dl) when measured at 31 weeks of gestation. Her serum anti SS-A and SS-B antibodies, anti-thyroglobulin, and microsomal antibodies were negative. A male infant without cardiac anomalies was delivered at 35 weeks and 4 days of gestation and admitted for prematurity and respiratory distress syndrome. The infant's heart rate was 70-110 bpm (normal: 120-160 bpm) on admission. On 8 days of age, thyroid function tests revealed that the infant had severe hypothyroidism (TSH 903.3 μIU/ml, free T3 1.05 pg/ml, and free T4 0.26 ng/dl). The prolonged jaundice assumed to be due to hypothyroidism. Oral levothyroxine sodium hydrate (10 μg/kg/ day) was immediately started on day 8. After the treatment, the heart rate was gradually increased to 130-140 bpm as the infant's thyroid function was improved (TSH 79.8 μIU/ml, free T3 2.95 pg/dl, and free T4 1.66 ng/dl on day 22). The infant was diagnosed ectopic thyroid tissue because of the high thyroglobulin level (85.9 μ g/l). In conclusion, congenital hypothyroidism should be included in the differential diagnosis in cases of fetal bradycardia without cardiac anomalies or maternal autoimmune diseases.

The purpose of this study was to investigate changes in cranial shape among preterm neonates aged 1–6 months and the relationship between developmental quotient (DQ) and cranial shape at 6 months of age. Preterm infants who were hospitalized in our hospital were prospectively followed for 6 months. The cephalic index (CI) and cranial vault asymmetry index (CVAI) were evaluated at 1 (T1), 3 (T2), and 6 months (T3) of age and compared with those of the full-term infants. The relationship between CI or CVAI and DQ at T3 was analyzed using the Enjoji Scale of Infant Analytical Development. A total of 26 participants born at 34.7 ± 1.9 weeks of gestation were included. The CI increased with age (T1: 77.2%, T2: 82.9%, T3: 85.4%, p < 0.01). The prevalence of dolichocephaly at T3 did not significantly differ from that in full-term infants (15.4% vs. 4.5%, p = 0.08). CVAI did not significantly differ between preterm and full-term infants. The DQ showed no significant correlation with either the CI or CVAI (correlation coefficients: 0.23 for CI, −0.01; CVAI). Dolichocephaly improved over time in preterm infants and no relationship between cranial shape and development was observed in preterm infants at 6 months of age.

We assessed a method for screening the cranial shape of 1-month-old infants using a simple measuring instrument instead of a three-dimensional scanner. The Mimos craniometer was used to measure cranial length, cranial width, and two diagonal lengths to calculate the cranial index (CI) and cranial asymmetry (CA). We defined a CI > 90% as brachycephaly and CA > 5 mm as deformational plagiocephaly (DP). Intra- and inter-examiner accuracy analyses were performed on a dummy doll and 1-month-old infants. The measurements of healthy 1-month-old infants were compared with previously reported three-dimensional scanner measurements. Intra- and inter-rater measurements showed good accuracy; diagnostic accuracy comparisons of brachycephaly and DP using a three-dimensional scanner showed kappa values of 1.0 and 0.8, respectively. Comparisons were made among 113 infants matched for day-age at the date of measurement; there were no significant differences in the CI (85.0% vs. 85.2%, p = 0.98) and CA (5.9 mm vs. 6.0 mm, p = 0.48) between the scanner and caliper measurements, nor in the prevalence of brachycephaly (12.4% vs. 17.7%, p = 0.35) or DP (58.4% vs. 56.6%, p = 0.89). This simple measurement method using calipers and bands was useful in screening for brachycephaly and DP in 1-month-old infants.