Effect of perinatal asphyxia on thyroid-stimulating hormone and thyroid hormone levels

AIM: To compare serum concentrations of thyroid hormones--T4, T3, free T4 (FT4) and reverse T3 (rT3)--and thyroid-stimulating hormone (TSH) found in the umbilical cord blood of term newborns with and without asphyxia and those found in their arterial blood collected between 18 and 24 h after birth. A further aim of the study was to assess the association between severity of hypoxic-ischemic encephalopathy and altered thyroid hormone and TSH levels, and between mortality and FT4 levels in the arterial blood of newborns between 18 and 24 h of life. METHODS: A case-control study was carried out. The case group comprised 17 term newborns (Apgar score < or = 3 and < or = 5 at the first and fifth minutes; umbilical cord blood pH < or = 7.15) who required bag and mask ventilation for at least one minute immediately after birth. The control group consisted of 17 normal, term newborns (Apgar score > or = 8 and > or = 9 at the first and fifth minutes; umbilical cord blood pH > or = 7.2). Cord blood and arterial blood samples were collected immediately after birth and 18 to 24 h after birth, respectively, and were used in the blood gas analysis and to determine serum concentrations of T4, T3, FT4, rT3 and TSH by radioimmunoassay. All newborns were followed-up until hospital discharge or death. RESULTS: Gestational age, birthweight, sex, size for gestational age, mode of delivery and skin color (white and non-white) were similar for both groups. No differences were found in mean levels of cord blood TSH, T4, T3 and FT4 between the groups. In the samples collected 18 to 24 h after birth, mean levels of TSH, T4, T3 and FT4 were significantly lower in the asphyxiated group than in the control group. Mean concentrations of arterial TSH, T4 and T3 between 18 and 24 h of life were lower than concentrations found in the cord blood analysis in asphyxiated newborns, but not in controls. In addition, asphyxiated newborns with moderate/severe hypoxic-ischemic encephalopathy presented significantly lower mean levels of TSH, T4, T3 and FT4 than those of controls. None of the asphyxiated newborns with FT4 > or = 2.0 ng/dl died; 6 out of the 11 asphyxiated newborns with FT4 < 2.0 ng/dl died. CONCLUSIONS: Serum concentrations of TSH, T4, T3 and FT4 are lower in asphyxiated newborns than in normal newborns between 18 and 24 h of life; this suggests central hypothyroidism secondary to asphyxia. Asphyxiated newborns with moderate/severe hypoxic-ischemic encephalopathy present a greater involvement of the thyroid function and consequently a greater risk of death.     

Povidone-iodine in umbilical cord care interferes with neonatal screening for hypothyroidism

Out of 1346 newborns screened for congenital hypothyroidism, 31 non-hypothyroid infants were summoned because of a thyroid stimulating hormone (TSH) level above 10 U/ml. False-positive TSH levels were significantly more frequent in the babies treated with povidone-iodine (4.6%) than in those treated with either alcohol or triple dye (0.7%).Conclusion Iodine containing solutions should be avoided in umbilical cord care of the newborn     

Identification and characterization of two groups of congenital hypothyroid infants: implications for newborn screening

A retrospective analysis of 400 newborns diagnosed with congenital primary hypothyroidism between 1983 and 1987 was conducted. Two distinct groups of cases were identified and characterized based on their newborn screening TSH value. The two groups are separated at a TSH concentration of 50 mU/1 of serum by a normal probability plot. This finding is in agreement with the 1993 recommendation from the American Academy of Pediatrics that infants with a low T4 level and a TSH concentration greater than 40 mU/1 be considered to have primary hypothyroidism until proven otherwise. The group of infants with TSH less than 50 mU/1 have a higher proportion of males and low birthweight infants. For this group, T4 increases with increasing TSH. We find that screening TSH, T4, and birthweight are predictive of follow-up serum TSH level for the cases with TSH > 50 mU/1 but not for cases with TSH < 50 mU/1. An optimal rule for selecting screening cutoff levels is presented based on only T4, TSH and their interaction. Adjustments for sex, birthweight or age at which sample was taken did not aid in distinguishing cases from controls for newborns whose age of sample is 2 days or greater.     

SERUM LEVELS OF THYROTROPIN, THYROXINE AND TRIIODOTHYRONINE IN FULLTERM, SMALL-FOR-GESTATIONAL AGE AND PRETERM NEWBORN BABIES

Abstract. Simultaneous serum concentrations of TSH, total thyroxine (T₄) and triiodothyronine (T₃) were determined in 93 fullterm (FT), 37 small-for-gestational age (SGA) and 38 preterm (PT) babies with a postnatal age from 2 to 144 hours. In addition, TSH, T₄ and T₃ concentrations were measured in cord sera from 27 FT, 4 SGA and 5 PT babies and in venous blood from 20 mothers at delivery. Cord blood concentrations of TSH were higher and T₄ and T₃ concentrations were lower than seen in the mothers. Serum concentrations of TSH were high during the first day of life followed by a decline. There was no statistically significant difference between serum TSH concentrations of the three groups of newborns. On the 5th day of life no elevated serum TSH values were found in any of the groups (TSH<5mU/l). Serum concentrations of thyroid hormones increased after birth and reached maximum levels within 24 hours in all groups. The relative increases above cord level were of the same magnitude in the newborns: Two times for serum T₄ and six times for serum T₃. The thyroid hormone concentrations in blood samples from FT babies decreased from the second day of life, whereas in low birth weight newborns the decreases were more variable. The serum levels of T₄ and T₃ were significantly different in the three groups of newborns, the highest values were seen in FT and the lowest values in PT babies. In contrast, the ratios between molar serum concentrations of T₄ and T₃ were found to be highest in PT, lower in SGA and lowest in FT babies, approaching maternal values during the first week of life. The data are discussed with regard to hormone secretion, thyroxine-binding capacity and peripheral T₄ to T₃ conversion in the three groups of newborns. It is concluded that from day 5 after birth serum TSH determinations, alone or in combination with serum T₄, seem to be the method of choice in screening for congenital hypothyroidism.     

Resetting the detection level of cord blood thyroid stimulating hormone (TSH) for the diagnosis of congenital hypothyroidism

An appraisal of a 17-year primary thyroid stimulating hormone (TSH) screening programme for the detection of congenital hypothyroidism was carried out to establish the reference interval of cord blood TSH in unaffected infants; the mean cord blood TSH concentration of affected infants and the incidence of congenital hypothyroidism in the Najran province of Saudi Arabia. Our findings show a reference interval of cord blood TSH of 2.0-16.8 mU/l in unaffected infants; a mean cord blood TSH concentration of 399 mU/l in affected infants; a false positive rate for the diagnosis of at-risk infants of 1.02% and a congenital hypothyroidism incidence rate of 34/100 000 (1 : 2931) live births. These findings suggest that there is a need to reset the cord blood TSH concentration for the detection of at-risk infants. We suggest that the detection level of cord blood TSH for the recognition of at-risk infants can be set at 90 mU/l rather than the recommended level of 30 mU/l. This should reduce the false positive rate for detection of infants at risk of congenital hypothyroidism.     

Direct assay of free thyroxine in children. Application to the monitoring of the treatment of hypothyroidism

A direct measurement of free thyroxine (FT4) by a radio-immunologic method using an analogue of thyroxine as tracer allowed to establish the normal values in 341 children from birth to puberty. These values were used as reference for the determination of free T4 in the diagnosis and management of treatment for congenital hypothyroidism. In 44 treated hypothyroid children, there was a positive correlation between the serum concentration of free T4 and the amount of levothyroxine given daily (r = 0.46, p less than 0.01). There was also a negative correlation between free T4 and serum TSH (r = 0.59, p less than 0.001). Thus, the measurement of free thyroxine seems to be a more reliable, more accurate and more sensitive parameter than that of total thyroxine or TSH for controlling the treatment of congenital hypothyroidism.     

Congenital oral mucosal abnormalities in true umbilical cord knots

OBJECTIVE: The pathogenesis and clinical significance of true umbilical cord knots remain controversial. Here, we tested the hypothesis of the presence of congenital oral mucosal changes in newborns with true umbilical cord knots. STUDY DESIGN: Seven consecutive infants with true umbilical cord knots and 50 gestational age- and sex-matched controls were enrolled. The proportion of oral frenulum abnormalities and the two-dimensional vascular network geometry [fractal dimension, D, at two scales: D(1-46), and D(1-15), with the relative Lempel-Ziv complexity, (L-Z)], were analyzed. RESULTS: Infants with true umbilical cord knots showed significantly higher proportions of mandibular frenulum agenesis compared to controls (p = 0.000006). The oral vascular networks of these infants exhibited a significantly higher D(1-46) and D(1-15) (p < 0.0001, respectively), and higher L-Z values (p < 0.0001) than control networks. CONCLUSION: These findings indicate the presence of significant congenital oral mucosal changes in newborn infants with true umbilical cord knots, thus suggesting a previously unrecognized association between true umbilical cord knots and a subclinical extracellular matrix disorder.     

Cord blood thyroid‐stimulating hormone and free T4 levels in Turkish neonates: Is iodine deficiency still a continuing problem?

Background: The objectives of this study were to determine the cord blood thyroid‐stimulating hormone (TSH) and free T₄ (FT₄) levels in Turkish neonates and to determine whether these variables reveal iodine deficiency. Methods: We collected 818 cords from healthy mothers at parturition and measured levels of FT₄ and TSH. We also measured cord blood FT₄ and TSH levels in different stages of gestation and gender. We grouped the neonates according to cord serum TSH levels, either being less (Group A) or greater (Group B) than 10 mIU/L. Group A included 589 neonates (300 girls [51%] and 289 boys [49%]) and Group B included 229 neonates (105 girls [45%] and 124 boys [55%]). Results: The percentage of subjects with cord blood TSH < 10 mIU/L and >10 mIU/L was 72% and 28%, respectively. Although cord TSH levels in Group B were greater than those in Group A (P < 0.001), cord blood FT₄ levels in Group B were lower than those in Group A (P < 0.05). There was no difference between both sex in terms of birthweight and maternal age. TSH and FT₄ levels did not vary according to neonate sex during gestation, except for from week 37 to 41. TSH levels of male neonates at the 41st week of gestation were higher than those of female neonates (P < 0.05). There were no effects of birthweight on TSH and FT₄ levels if the neonate was lighter than 2500 g at birth. TSH levels of male neonates were higher than those of female neonates when their birthweights were <2500 g (P < 0.05). There was no significant difference in TSH levels according to birthweights in male neonates. Conclusion: Our data provide the normative data for cord blood TSH and FT₄ levels in Turkish neonates and show that iodine deficiency is a still a public health problem in Turkey. These measurements can be useful for detection and verification of hypothyroidism in a screening program for congenital hypothyroidism as well as evaluation of the success of the iodination program.     

Screening for congenital hypothyroidism in Hong Kong

A pilot cord blood TSH screening program for congenital hypothyroidism was commenced in Hong Kong in April 1982. By April 1984, 14 411 neonates born in two hospitals were screened for this disorder. Five cases of primary hypothyroidism and two cases of transient hypothyroidism were detected. The detection of cases of congenital hypothyroidism with only moderately elevated cord blood TSH values means that the recall rate will remain high.     

Screening for congenital hypothyroidism in Hong Kong

A pilot cord blood TSH screening program for congenital hypothyroidism was commenced in Hong Kong in April 1982. By April 1984, 14 411 neonates born in two hospitals were screened for this disorder. Five cases of primary hypothyroidism and two cases of transient hypothyroidism were detected. The detection of cases of congenital hypothyroidism with only moderately elevated cord blood TSH values means that the recall rate will remain high.     

Effect of perinatal asphyxia on thyroid hormones

OBJECTIVE: To verify the effect of perinatal asphyxia on thyroid hormone levels in term newborn infants. METHODS: We carried out a case-control study with 17 term and asphyxiated (A) and 17 term and control (N) newborn infants at the Hospital de Clínicas de Porto Alegre. Patients were paired according to color of skin, sex, type of delivery, gestational age, and weight at birth. We collected umbilical cord plasma T4, T3, free T4, reverse T3, and TSH after 18 to 24 hours of life and from asphyxiated and control newborn infants. RESULTS: There were no differences in thyroid hormones of cord blood, with the exception of reverse T3, which was higher in A than in controls [median (25th-75th percentile): A= 2(1.4-2); N= 1.41 (1.13-1.92); P=0.037)]. Thyroid hormone levels were lower in A than in controls on samples collected within 18-24 hours after birth, except for reverse T3, which was similar in both groups [average -/+ SD: T4 A= 9.79 -/+ 2.59; N=14.68 -/+ 3.05; P<0.001; median T3 A= 40.83 (37.4-80.4); N= 164 (56.96-222.5); P=0.003; average -/+ SD: free T4 A=1.85 -/+ 0.92; N= 2.8 -/+ 0.74; P=0.004; median: reverse T3 A=1.54 (1.16-1.91); N=1.31(0.87-2); P=0.507; TSH A=9.1 (6.34-12.95); N=14.5(12.9-17.85); P=0.008]. CONCLUSIONS: Our data suggest that lower T4, free T4, and T3 levels are secondary to lower TSH levels in asphyxiated newborns; also, peripheral metabolism of T4 in asphyxiated infants can be altered due to low T3 and normal reverse T3 levels.     

Influence of Mode of Delivery on Fetal Pituitary-Thyroid Axis

We measured the cord serum levels of thyroid-stimulating hormone (TSH), thyroxine (T4) and triiodothyronine (T3) in 922 neonates delivered by mothers who had no thyroid disorders. The T4 and T3 levels increased progressively from the 27th to the 40th week of gestation. However, the TSH levels varied widely and had no correlation with gestational age, because they were affected by the mode of delivery. The mean cord serum TSH level in neonates delivered by vacuum extraction was 16.3 ±10.0 µUml (n = 30), which was significantly higher than the level following normal vaginal delivery (9.5 ± 6.0 µ U/ml, n = 622) (p < 0.005). The mean cord serum TSH level following elective caesarean section was 6.5 ± 3.1 µ U/ml (n = 79), and this was significantly lower than after normal vaginal delivery (p< 0.005). TSH levels in high-risk neonates were significantly higher than in neonates without risk factors. A significant positive correlation was found between the duration of the second stage of labor and the cord serum TSH level (r = 0.45, n = 412, p<0.01). However, there was no correlation between the cord serum TSH level and the congenital hypothyroidism screening TSH level (r = 0.01, n = 468). We conclude that the cord serum TSH level reflects delivery stress and that an elevated level does not influence the congenital hypothyroidism screening TSH test in which blood is obtained at five days of life.     

血管内皮生长因子在重度子癎痫前期产妇新生儿脐血中的表达

目的 探讨血管内皮生长因子(VEGF)在重度子癎前期产妇分娩的新生儿脐静脉血、脐动脉血中的表达及其意义.方法 采用放射免疫分析法检测26例重度子癎前期产妇所分娩新生儿(重度子癎前期组)与30例健康产妇所分娩新生儿(对照组)的脐静脉血、脐动脉血VEGF水平.重度子癎前期组新生儿按照其出生体质量-胎龄分类分为小于胎龄儿15例(SGA组)和适于胎龄儿11例(AGA组).结果 (1)重度子癎前期组脐静脉血、脐动脉血VEGF水平[(15.26±5.28)pg/ml、(19.334±4.45)pg/ml]均显著高于对照组[(12.78±3.21)pg/ml、(14.55±2.90)pg/ml](t=2.16,P<0.05;t=4.82,P<0.01).(2)对照组和重度子癎前期组的脐动脉血VEGF水平均显著高于脐静脉血VEGF水平(t=2.24,P<0.05;t=3.00,P<0.01).(3)对照组和重度子癎前期组脐静脉血和脐动脉血VEGF水平与新生儿胎龄或出生体质量均无明显相关性.(4)重度子癎前期SGA组的脐动脉血VEGF水平(21.38±3.68pg/ml)显著高于AGA组(16.53±3.96pg/ml)和对照组(t=3.22,P<0.01;t=6.80,P<0.01).结论 重度子癎前期产妇新生儿脐静脉血和脐动脉血VEGF水平均较健康产妇新生儿明显升高;脐动脉血VEGF水平在一定程度上可反映妊娠期高血压疾病产妇的新生儿宫内损伤程度.     

血管内皮生长因子在重度子癎痫前期产妇新生儿脐血中的表达

目的 探讨血管内皮生长因子(VEGF)在重度子癎前期产妇分娩的新生儿脐静脉血、脐动脉血中的表达及其意义.方法 采用放射免疫分析法检测26例重度子癎前期产妇所分娩新生儿(重度子癎前期组)与30例健康产妇所分娩新生儿(对照组)的脐静脉血、脐动脉血VEGF水平.重度子癎前期组新生儿按照其出生体质量-胎龄分类分为小于胎龄儿15例(SGA组)和适于胎龄儿11例(AGA组).结果 (1)重度子癎前期组脐静脉血、脐动脉血VEGF水平[(15.26±5.28)pg/ml、(19.334±4.45)pg/ml]均显著高于对照组[(12.78±3.21)pg/ml、(14.55±2.90)pg/ml](t=2.16,P<0.05;t=4.82,P<0.01).(2)对照组和重度子癎前期组的脐动脉血VEGF水平均显著高于脐静脉血VEGF水平(t=2.24,P<0.05;t=3.00,P<0.01).(3)对照组和重度子癎前期组脐静脉血和脐动脉血VEGF水平与新生儿胎龄或出生体质量均无明显相关性.(4)重度子癎前期SGA组的脐动脉血VEGF水平(21.38±3.68pg/ml)显著高于AGA组(16.53±3.96pg/ml)和对照组(t=3.22,P<0.01;t=6.80,P<0.01).结论 重度子癎前期产妇新生儿脐静脉血和脐动脉血VEGF水平均较健康产妇新生儿明显升高;脐动脉血VEGF水平在一定程度上可反映妊娠期高血压疾病产妇的新生儿宫内损伤程度.     

С��̥�����ѪGhrelin��̥������������л���ϵ���о�

目的 通过比较小于胎龄儿(SGA)和足月正常新生儿脐血Ghrelin水平的变化,分析脐血Ghrelin与新生儿出生体重、身长、头围、BMI和胎盘重量、胎盘体积的关系,以及脐血Ghrelin水平与IGF-1、胰岛素、胰岛素敏感性和血糖的关系.探讨脐血Ghrelin水平与胎儿发育和代谢轴之间,尤其是Ghrelin与IGF-1的相互关系.方法 2006年12月至2007年3月选择中山大学附属一院新生儿78例,SGA组22例为观察组,足月适于胎龄儿(AGA)42例为正常对照组.采用酶联免疫反应法(ELISA)对新生儿脐血Ghrelin、胰岛素、IGF-1进行测定分析,测量新生儿净体重、身长、头围、胎盘体积、胎盘重量,计算体重指数(BMI)和胰岛素敏感指数(ISI).结果 (1)SGA组脐血Ghrelin水平(38.74±4.90 ng/mL)明显高于正常对照组(23.37±8.78 ng/mL),其差异有统计学意义(P＜0.05).(2)脐血Ghrelin水平与新生儿出生体重、身长、头围、BMI、胎盘重量、胎盘体积呈负相关,均有统计学意义(P＜0.05).(3)脐血Ghrelin水平与IGF-1、胰岛素、ISI呈负相关均有统计学意义(P＜0.05).与血糖无相关性(r=0.081,P=0.454).(4)通过偏相关分析,控制出生体重、身长、胎盘重量、BMI、胰岛素后,Ghrelin与IGF-1有明显负相关性,有统计学意义.(5)剖宫产新生儿脐血Ghrelin水平与顺产儿无明显差异(P=0.956);男性与女性新生儿脐血Ghrelin水平无明显差异(P=0.385).结论 新生儿脐血Ghrelin水平是反映胎儿的宫内发育及营养状态的指标之一.并以负反馈形式参与胎儿宫内发育和代谢轴的调控过程.小于胎龄儿出生时可能存在胰岛素抵抗.小于胎龄儿高Ghrelin并没有刺激胰岛素释放,提示小于胎龄儿可能存在Ghrelin受体或受体后信号传导通路的抵抗.     

新生儿血清EPO水平与孕周、日龄的关系

研究不同孕周出生的新生儿脐血及不同日龄静脉血的EPO水平 ,并分析其与贫血的关系 ,分别取 4 9例早产儿与 4 6例足月儿脐静脉血清 1ml;并对其中 1 8例早产儿于生后第 7天、1 4天、2 8天取静脉血清 1ml,对其中 1 7例足月儿于生后第 7天取静脉血 1ml,用ELISA方法检测EPO值 ,结果显示 :( 1 )早产儿与足月儿脐血EPO水平无显著差异 (P >0 0 5)。 ( 2 )足月儿生后第 7天血清EPO与脐血比较有显著差异 (P <0 0 0 1 )。早产儿生后第 7天、1 4天、2 8天EPO值与脐血比较明显降低 ,有极显著差异 (P <0 0 0 1 )。因此 ,初步结论 ,新生儿脐血EPO水平与孕周无关。新生儿生后 7天血中EPO水平迅速下降 ,早产儿下降幅度比足月儿更显著 ,持续下降到生后2 8天无上升趋势 ,早产儿贫血多发生在新生儿早期 ,与此时期血中EPO水平大幅度下降有关 ,故用rhEPO治疗早产儿贫血应早期应用。     

脐血IGF-1及IGFBP-3与胎儿生长发育的关系研究

目的探讨胰岛素样生长因子-1（IGF—1）及胰岛素样生长因子结合蛋白-2（IGFBP-3）与胎儿宫内生长发育的关系。方法将新生儿根据出生体重与胎龄的关系分为大于胎龄儿（IAG）、适于胎龄儿（AGA）、小于胎龄儿（SGA）三组,分别测定三组新生儿出生时身长、体重及胎盘重量,同时取脐血采用EUSA法测定IGF-1及IGFBP-3水平。结果①三组新生儿出生时身长、体重及胎盘重量3个指标比较差异均有统计学意义（P均〈0．05）。②脐血IGF-1及IGFBP-3水平在SGA、AGA、LGA三组间比较,LGA组〉AGA组〉SGA组,各组间比较差异均有统计学意义（P均〈0.05）。③胎儿发育的重要指标出生体重、身长及胎盘重量与IGF-1及IGFBP-3水平均呈正相关。结论IGF-1及IGFBP-3与胎儿生长发育密切相关,对胎儿的生长发育起重要的调节作用。     

骨钙素、Ⅰ型前胶原羧基端前肽、胰岛素样生长因子-1及其相关激素与胎儿骨发育的关系

目的 探讨骨钙素(OC)、Ⅰ型前胶原羧基端前肽(PICP) 及胰岛素样生长因子.1(IGF.1)等激素水平与胎儿骨生长发育的关系.方法 选择本院2008年10月-2009年10月收治的新生儿80例.男41例,女39例;胎龄28～42周.根据不同出生体质量分为小于胎龄(SGA)儿组22例,适于胎龄(AGA)儿组36例及大于胎龄(LGA)儿组(22例).胎儿娩出后,胎盘娩出前抽取其脐静脉血6 mL,采用放射免疫分析法测定其血清OC、IGF.1及甲状旁腺激素水平,酶联免疫吸附法检测其脐血PICP水平;同时检测其血钙、磷、ALP水平,测量新生儿生长参数,计算体质量指数(BMI).结果 1.脐血OC水平在SGA儿组、AGA儿组、LGA儿组间比较差异有统计学意义(P=0.000),LGA儿组显著高于AGA儿及SAG儿组(P＜0.01,0.001);脐血OC水平与出生体质量、头围、BMI呈正相关(Pa＜0.05),与身长无明显相关性(P＞0.05).2.LGA儿组脐血IGF.1水平显著高于AGA儿及SAG儿组,3组间比较有统计学差异(P=0.002);脐血IGF.1水平与出生体质量、头围、BMI水平均呈正相关(Pa＜0.05),与身长无明显相关性(P＞0.05).3.AGA儿组、LGA儿组脐血PICP水平明显高于SGA儿组,但3组间无统计学差异(P=0.070).脐血PICP、PTH水平与生长参数各指标水平均无直线相关关系(Pa＞0.05),偏相关分析脐血PICP与出生体质量、头围、BMI均呈正相关(r=0.239、0.250、0.306,Pa<0.05).4.脐血OC水平与PICP、IGF.1水平均呈正相关(Pa＜0.05),OC、PICP与PTH、ALP水平之间均无明显相关(Pa＞0.05).5.3组脐血钙、血磷、ALP水平均无统计学差异(Pa＞0.05).结论 SGA儿低血清OC、PICP水平与骨形成活动下降相关,脐血OC、PICP及IGF.1可作为评价胎儿骨骼生长发育的临床指标之一.     

SCREENING FOR CONGENITAL HYPOTHYROIDISM

ABSTRACT. Larsson, A., Ljunggren, J. G., Ekman, K., Nilsson, A. and Olin, P. (Departments of Paediatrics and Child Psychiatry, Karolinska Institute, St. Goran's Children's Hospital; the Department of Medicine, St. Göran's Hospital; and the PKU Section of the Department of Bacteriology, National Bacteriological Laboratory, Stockholm, Sweden). Screening for congenital hypothyroidism. I. Laboratory results of a pilot study based on dried blood samples collected for PKU screening. Acta Paediatr Scand, 70:141, 1981. – A pilot study was performed to establish optimal conditions for nation-wide screening for congenital hypothyroidism in Sweden. The levels of T₄ and TSH were determined by automated radioimmunoassay in the dried blood spots, routinely collected for PKU screening on the fifth postnatal day, from all 1979, 2 infants born in the Stockholm area during a 14-month period. To identify safe minimum recall criteria for routine use, infants were recalled if the TSH level was more than 30 mU/l of plasma or–if they were not preterm–the T₄ concentration was less than -2 S.D. of the mean. Altogether 160 infants were recalled. Seven newborns with congenital hypothyroidism were identified, 6 with primary and one with secondary hypothyroidism. Five infants had decreased levels of thyroxine-binding globulin. The results of the follow-up analyses from recalled infants showed that determination of the reverse-T₃ level may be of diagnostic value around the 23rd day of life. The results of the clinical investigation of recalled infants are reported in a subsequent paper and a programme for nation-wide screening for congenital hypothyroidism is proposed.     

Adrenocorticotrophic hormone during the first day of life

The plasma concentration of ACTH (by radioimmunoassay) was measured in 56 healthy parturients and their newborns. Umbilical cord and maternal venous blood were collected immediately after delivery. In addition one venous blood sample was taken from 50 newborns at the age of 15, 30, 60 min, 2, 6, 12, or 24 h.The maternal and cord plasma ACTH levels were higher than the levels in healthy nonpregnant women. There are no differences between the mean maternal (226±146 pg/ml) and cord (226±147 pg/ml) values of ACTH.The high ACTH levels of cord plasma remain unchanged for 30 min, decrease significantly during the 1–6 h after birth, because of the elimination process of the circulated foetal ACTH, and increase over the next 12–24 h and slightly thereafter indicating an initiation of neonatal pituitary ACTH secretion.The plasma ACTH level in the mothers with membranes ruptured for 1–5 h was significantly (P<0.05) higher compared with that in the mothers with membranes ruptured for less than 1 h. However, the duration of ruptured membranes appeared to have no effect on the cord blood ACTH level.