The effect of maternal subclinical hypothyroidism on IQ in 7- to 8-year-old children: A case-control review.

BACKGROUND: In Ireland, pregnant women are not routinely screened for subclinical hypothyroidism (SCH). AIM: Our objective was to compare the intelligence quotient (IQ) of children whose mothers had been diagnosed with SCH prenatally with matched controls using a case-control retrospective study. MATERIALS AND METHODS: In a previous study from our group, 1000 healthy nulliparous women were screened anonymously for SCH. This was a laboratory diagnosis involving elevated TSH with normal fT4 or normal TSH with hypothyroxinaemia. We identified 23 cases who agreed to participate. These were matched with 47 controls. All children underwent neurodevelopmental assessment at age 7-8. Wechsler Intelligence Scale for Children IV assessment scores were used to compare the groups. Our main outcome measure was to identify whether there was a difference in IQ between the groups. RESULTS: From the cohort of cases, 23 mothers agreed to the assessment of their children as well as 47 controls. The children in the control group had higher mean scores than those in the case group across Verbal Comprehension Intelligence, Perceptual Reasoning Intelligence, Working Memory Intelligence, Processing Speed Intelligence and Full Scale IQ. Mann-Whitney U-test confirmed a significant difference in IQ between the cases (composite score 103.87) and the controls (composite score 109.11) with a 95% confidence interval (0.144, 10.330). CONCLUSIONS: Our results highlight significant differences in IQ of children of mothers who had unrecognised SCH during pregnancy. While our study size and design prevents us from making statements on causation, our data suggest significant potential public health implications for routine prenatal screening.

Three-tesla cardiac magnetic resonance imaging for preterm infants.

OBJECTIVES: We aimed to establish the feasibility of acquiring 3.0-T cardiac MRIs without sedation, anesthesia, or breath-holding for preterm infants and to obtain preliminary quantitative data on left ventricular function in this population. METHODS: Twelve preterm infants underwent 3.0-T cardiac MRI without sedation or breath-holding. The median gestational age was 29 weeks (range: 26-33 weeks), the median birth weight was 1240 g (range: 808-2200 g), and the median postconceptional age at the time of cardiac MRI was 33 weeks (range: 31-40 weeks). Anatomic images were acquired with T2-weighted spin-echo sequences, and ventricular function was assessed with balanced steady-state free precession cine sequences. We assessed left ventricular function by using the area-length ejection fraction method on horizontal long-axis images and the volumetric Sergeant's discs method of analysis on short-axis images. RESULTS: Imaging was successful for 10 of 12 infants. For those 10, the area-length ejection fraction method in the horizontal long-axis plane estimated median stroke volume at 2.9 mL, cardiac output at 0.4 L/minute, end-diastolic volume at 3.8 mL, end-systolic volume at 0.3 mL, and ejection fraction at 74.6%. Short-axis volumetric estimations were made for 4 infants. With this approach, the median stroke volume was 2.4 mL, cardiac output 0.35 L/minute, end-diastolic volume 4.3 mL, end-systolic volume 2.1 mL, and ejection fraction 56%. CONCLUSIONS: Three-tesla cardiac MRI is feasible for preterm infants without sedation, anesthesia, or breath-holding and has the potential to provide a wide range of precise quantitative data that may be of great value for the investigation of cardiac function in preterm infants.