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Biomedical subjects

J G Thorpe-Beeston

Publications and source records attributed to J G Thorpe-Beeston.

13 recordsLinked to original sources
PubMed1992

Outcome of breech delivery at term.

OBJECTIVE: To compare neonatal mortality and morbidity in term infants presenting by the breech and delivered vaginally or by caesarean section. DESIGN: Population based comparison of outcomes. Data derived from the St Mary's maternity information system. SETTING: North West Thames Regional Health Authority, 1988-90. SUBJECTS: 3447 singleton fetuses presenting by the breech at term. MAIN OUTCOME MEASURES: Intrapartum and neonatal mortality, low Apgar scores, intubation at birth, and admission to special care baby units. RESULTS: After the exclusion of babies with congenital anomalies the incidence of intrapartum and neonatal death associated with vaginal birth was 8/961 (0.83%) compared with 1/2486 (0.03%) in babies born by caesarean section (relative risk 20, 95% confidence interval 2.5 to 163). The numbers of low Apgar scores and neonatal intubation were doubled in babies born vaginally or by emergency caesarean section compared with those delivered by elective operation. CONCLUSIONS: The good neonatal outcome associated with elective caesarean delivery of the term breech fetus may influence the decision of women and their obstetricians about mode of delivery.

Apgar Score↗
PubMed1992

Fetal thyroid function.

Cordocentesis has permitted the study of fetal thyroid function in utero. In normal fetuses, fetal TSH, TBG, and thyroid hormone concentrations increase progressively throughout intrauterine life. Fetal TSH concentrations are always high compared to nonpregnant adult values. TBG concentrations reach adult levels at term. TT4 and FT4 concentrations reach adult levels at approximately 36 weeks gestation, but TT3 and FT3 are always below adult concentrations. There are no significant associations between fetal and maternal concentrations of TSH, TBG, or thyroid hormones. The maternal administration of TRH from at least 25 weeks gestation stimulates the fetal pituitary gland to produce TSH. The response is rapid, unrelated to gestational age, and much greater than that of the mother. These findings suggest that in intrauterine life there is independent and autonomous maturation of the pituitary, thyroid, and liver. The fetal pituitary is able to respond to the maternal administration of TRH and appears to be more sensitive than in the adult. In small-for-gestational-age fetuses, the concentrations of TSH are higher and the concentrations of TT4 and FT4 are lower than in appropriately grown fetuses. The degrees of elevation of TSH and fall in thyroid hormones are significantly related to the degree of fetal hypoxemia and acidemia, respectively. Although the low concentrations of thyroid hormones may have some beneficial effects by reducing oxygen requirements, they may adversely affect brain development.

Animals↗
PubMed1992

Serum prolactin concentration in normal and small for gestational age fetuses.

OBJECTIVES: To study fetal and maternal serum prolactin concentrations in appropriately-grown (AGA) fetuses and in small for gestational age (SGA) fetuses. DESIGN: A cross-sectional study of 27 AGA and 27 SGA fetuses undergoing cordocentesis for prenatal diagnosis or for determination of fetal karyotype and acid-base balance. Serum prolactin concentration was measured by radioimmunoassay. SETTING: Harris Birthright Research Centre for Fetal Medicine. RESULTS: In the AGA group, both fetal and maternal serum prolactin concentration increased significantly with gestation (P < 0.001 and P < 0.01, respectively). In the SGA group, the fetal concentration of prolactin was significantly higher (P < 0.05), but the maternal serum prolactin concentration was not different from that of the AGA group. CONCLUSIONS: The finding of prolactin in the fetal circulation suggests that the anterior lobe of the pituitary is functioning from at least 12 weeks gestation. The increased serum prolactin concentration in SGA fetuses may be the consequence of hypoglycemic stress on the pituitary or the relative immaturity of the inhibitory hypothalamic-pituitary pathways.

Cross-Sectional Studies↗
PubMed1991

Maturation of the secretion of thyroid hormone and thyroid-stimulating hormone in the fetus.

BACKGROUND: Data on human fetal thyroid function have largely been derived from histologic studies or studies of cord-blood samples obtained at hysterotomy or delivery. These data may not represent true normal values. Cordocentesis (ultrasound-guided blood sampling from the umbilical cord) is a technique that allows investigation of physiologic processes in fetuses not under stress. METHODS: We measured serum thyroid-stimulating hormone, total and free thyroxine (T4), total and free triiodothyronine (T3), and thyroxine-binding globulin in blood samples from 62 fetuses. The samples were obtained by cordocentesis (n = 58) or cardiocentesis (n = 4) at 12 to 37 weeks of gestation. Maternal serum samples were obtained immediately before fetal blood sampling. RESULTS: Fetal serum thyroid-stimulating hormone, thyroxine-binding globulin, and total and free T4 and T3 concentrations increased significantly with the length of gestation (P less than 0.001). The only significant association among these variables, independent of the length of gestation, was between thyroid-stimulating hormone and free T4 (P less than 0.0001). Maternal serum concentrations of these variables did not change during gestation, and there was no significant relation between fetal and maternal values. Most fetal serum concentrations of thyroid-stimulating hormone were higher, whereas most serum total and free T3 concentrations were lower than the respective values for normal adults. The fetal serum total T4, free T4, and thyroxine-binding globulin values reached the level of the mean adult values at approximately 36 weeks of gestation. CONCLUSIONS: The increases in fetal serum concentrations of thyroid-stimulating hormone, thyroxine-binding globulin, and total and free T4 and T3 during gestation reflect increasing maturation of the pituitary, thyroid, and liver. The finding of increasing fetal serum concentrations of thyroid-stimulating hormone in the presence of increasing thyroid hormone concentrations suggests that the sensitivity of the fetal pituitary gland to negative feedback is limited or is counterbalanced by increasing stimulation by thyrotropin-releasing hormone from the hypothalamus.

Female↗
PubMed1991

Fetal thyroid-stimulating hormone response to maternal administration of thyrotropin-releasing hormone.

Thyroid-stimulating hormone was measured in fetal blood samples obtained by cordocentesis before and after blood transfusion in Rh-affected pregnancies at 25 to 37 weeks' gestation. In eight of 26 study subjects thyrotropin-releasing hormone was given to the mothers immediately after the pretransfusion samples were obtained. In this group the fetal thyroid-stimulating hormone concentrations in the posttransfusion samples were significantly higher than those before the transfusion.

Blood Transfusion, Intrauterine↗
PubMed1991

Relations between the fetal circulation and pituitary-thyroid function.

OBJECTIVE: To study the relation between changes in the fetal thyroid hormone and thyroid stimulating hormone (TSH) concentrations and alterations in the fetal circulation as assessed by Doppler ultrasound. DESIGN: A cross-sectional study of small for gestational age (SGA) and red-cell isoimmunized fetuses undergoing cordocentesis and Doppler studies for the assessment and determination of fetal karyotype, acid-base balance and haemoglobin concentration. SETTING: Harris Birthright Research Centre for Fetal Medicine, King's College, London. SUBJECTS: 38 growth retarded and 38 red-cell isoimmunised fetuses. INTERVENTIONS: Cordocentesis. MAIN OUTCOME MEASURES: Serum TSH total and free thyroxine (T4, FT4) and total and free triiodothyronine (T3, FT3) concentrations; middle cerebral artery (MCAVm) and descending thoracic aorta (AoVm) mean blood velocities; fetal Po2 and haemoglobin concentration (Hb). RESULTS: Delta values (delta) calculated as the number of SDs from the respective normal mean for gestation were used to compare the results with those from a previous study of normal fetuses. Mean AoVm was increased in the isoimmunized fetuses (P less than 0.001) but decreased in the SGA fetuses (P less than 0.001). Mean MCAVm was increased in both groups (P less than 0.01; P less than 0.001). There were significant associations between the gestational age adjusted values for TSH and MCAVm (r = 0.23, P less than 0.05) and between T4, FT4 or FT3 and AoVm (r = 0.41, P less than 0.01; r = 0.50, P less than 0.01; r = 0.36, P less than 0.01 respectively). In addition, T4 and FT4 were associated with delta Po2 and delta Hb. CONCLUSION: In the hypoxaemic hypoxia of growth retardation and the anaemic hypoxia of rhesus disease there are significant associations between changes in fetal thyroid hormone concentrations and changes in fetal blood flow as assessed by Doppler. Irrespective of whether altered blood flow is the cause or effect of changes in thyroid hormone concentrations, the observed changes could have beneficial effects for fetal survival, in the presence of a hostile intrauterine environment.

Blood Circulation↗
PubMed1991

Thyroid function in small for gestational age fetuses.

Thyroid function was studied in fetal blood samples obtained by funipuncture from 49 small for gestational age (SGA) fetuses at 21-38 weeks' gestation. Levels of TSH, thyroxine-binding globulin, thyroxine (T4), free T4, triiodothyronine (T3), and free T3 were compared with those from 62 appropriate for gestational age (AGA) fetuses. Levels of TSH were significantly higher and T4 and free T4 significantly lower in the SGA than in AGA fetuses. Furthermore, there were significant associations between the increase in TSH and decrease in free T4 and the degrees of fetal hypoxemia and acidemia, respectively.

Female↗
PubMed1990

Fetal lateral cerebral ventriculomegaly: associated malformations and chromosomal defects.

In 267 consecutive cases of fetal lateral cerebral ventriculomegaly, additional fetal malformations were detected by ultrasonography in 209 (78%) of the cases. On the basis of the ultrasound findings, the patients were subdivided into three groups: (i) isolated ventriculomegaly (n = 58), (ii) ventriculomegaly and open spina bifida only (n = 172), and (iii) ventriculomegaly and other malformations (n = 37) with or without spina bifida. Antenatal karyotyping was performed in 64 cases from groups (i) and (iii), and 11 (18%) of the fetuses had chromosomal abnormalities. The incidence of chromosomal abnormalities was strongly related to the presence of multisystem malformations. Thus, only 3% of fetuses with isolated ventriculomegaly as opposed to 36% of those with additional malformations had chromosomal defects. Furthermore, the degree of ventriculomegaly in the chromosomally abnormal fetuses was relatively mild. In the chromosomally normal fetuses, mild, static ventriculomegaly was associated with apparently normal subsequent mental development.

Abnormalities, Multiple↗
PubMed1990

Thyroid function in anemic fetuses.

Thyroid function was studied in 75 fetal blood samples obtained by cordocentesis from red cell isoimmunized pregnancies at 18-37 weeks of gestation. Thyroid-stimulating hormone (TSH), and free and total thyroxine and triiodothyronine were significantly higher than in normal controls. Furthermore, there was a significant association between the increase in TSH and the degree of fetal anemia.

Anemia↗
PubMed1990

Choroid plexus cysts and chromosomal defects.

During a 4-year period, 83 pregnant women with fetal choroid plexus cysts were investigated in our unit. Abnormal karyotypes were found in 20 fetuses, including trisomy 18 (n = 16), trisomy 13 (n = 1), triploidy (n = 1) and translocation Down's syndrome (n = 2). All fetuses with chromosomal defects had structural malformations in addition to the choroid plexus cysts.

Abnormalities, Multiple↗
PubMed1989

Mean red cell volume in normal, anemic, small, trisomic and triploid fetuses.

A reference range for fetal mean red cell volume (MCV) with gestation was established from the study of samples obtained by cordocentesis from 466 pregnancies undergoing prenatal diagnosis for non-erythrocyte abnormalities. The mean MCV decreased from 145 fl at 16 weeks to 113 fl at 36 weeks of gestation. Alterations in MCV were investigated in 154 red cell isoimmunized and 231 small for gestational age (SGA) fetuses. In red cell isoimmunization, significant macrocytosis was observed when the fetal hemoglobin concentration deficit was greater than or equal to 6 g/dl. In the chromosomally normal SGA fetuses (n = 178), the MCV was increased and the magnitude of macrocytosis was significantly associated with gestation and the degrees of fetal 'smallness' and fetal hypoxemia. However, the most severely macrocytotic SGA fetuses were those with triploidy (n = 22). In the SGA fetuses with other chromosomal defects (n = 31), the MCV was higher than the controls but lower than that of the chromosomally normal hypoxemic fetuses. It is suggested that in severe growth retardation there is developmental delay in the normal evolution from hepatic to medullary hemopoiesis and this is most marked in triploid fetuses. In contrast, in red cell isoimmunization the switch to medullary erythropoiesis is normal, but in severe anemia there is secondary recruitment of hepatic erythropoiesis.

Anemia, Hemolytic, Autoimmune↗
PubMed1989

Prenatal diagnosis of congenital diaphragmatic hernia: associated malformations and chromosomal defects.

In 36 fetuses with congenital diaphragmatic hernia (CDH) diagnosed at 18-36 weeks' gestation, detailed ultrasound examination was performed for the detection of associated malformations and assessment of the likelihood of pulmonary hypoplasia. In all cases karyotyping was undertaken in blood samples obtained by cordocentesis. In 11 (31%) fetuses there were lethal chromosomal abnormalities and in 6 (17%) of the chromosomally normal fetuses there were additional lethal malformations. Of the 17 fetuses with isolated CDH and where the pregnancy was not electively terminated. 9 (60%) survived and 6 (40%) died in the neonatal period due to pulmonary hypoplasia. The presence or absence of polyhydramnios, fetal breathing movements, mediastinal shift and thoracic position of the stomach were not useful in predicting postnatal outcome.

Abnormalities, Multiple↗