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Biomedical subjects

J Hyett

Publications and source records attributed to J Hyett.

At least 19 recordsLinked to original sources
PubMed2006

Uterine vein and maternal urinary levels of activin A and inhibin A in pre-eclampsia patients.

OBJECTIVES: The aims of this study were to investigate if (i) urinary concentrations of activin A and inhibin A are altered in pre-eclampsia (PE) and (ii) to study the relationship between uterine vein and peripheral vein concentrations of these hormones in PE patients. DESIGN AND METHOD: In a retrospective study, maternal peripheral vein and uterine vein serum and maternal urine samples collected at the time of delivery were analysed. There were three groups of patients; (i) group 1: term normal pregnancies (n = 19) (ii) group 2: patients who developed PE < or = 37 weeks (n = 17) and (iii) group 3: patients who developed PE 37-40 weeks (n = 8). Serum and urinary activin A, follistatin, inhibin A and pro alpha C and urinary creatinine levels were measured using enzyme immunoassays in the laboratory. RESULTS: Normal pregnant urine samples had very low levels of activin A and inhibin A. Both groups 2 and 3 PE patients had significantly higher levels of inhibin A (P < 0.001) and activin A (P < 0.001) compared to the controls. Pro-alpha C was not altered and follistatin was below the detection limit of the assay in the urine. Maternal peripheral serum activin A and inhibin A were significantly higher in groups 2 (P < 0.001) and 3 (P < 0.05) patients compared to the controls. Pro-alpha C-containing inhibins were higher in group 2 patients (P < 0.05) compared to the controls in the peripheral circulation. Uterine vein serum activin A and inhibin A levels were also significantly higher in groups 2 (P < 0.001) and 3 (P < 0.05) patients compared to the controls. There was a highly significant positive correlation between peripheral and uterine vein serum concentrations of activin A, follistatin, inhibin A and pro alpha C, suggesting the same source for these proteins in PE. CONCLUSION: Urinary activin A and inhibin A are raised in groups 2 and 3 PE patients. The magnitude of rise (> 25-fold) suggests these proteins may rise in patients before the onset of the clinical symptoms of PE. Uterine vein levels of these proteins are also raised in PE.

Activins↗
PubMed2004

Procedure-related complications of rapid amniodrainage in the treatment of polyhydramnios.

OBJECTIVE: To investigate the procedure-related complications of rapid amniodrainage in the treatment of polyhydramnios. METHODS: We followed prospectively all patients with polyhydramnios treated with rapid amniodrainage under continuous ultrasound guidance using a vacuum wound-drainage system from 1995 to 2002 in the fetal medicine unit of a university teaching hospital. We recorded: maternal age, type of pregnancy (singleton/twin), cause of polyhydramnios, gestational age at amniocentesis, volume of amniotic fluid drained, duration of the procedure, other intrauterine procedures in addition to the amniodrainage, and procedure-related complications including placental abruption, premature rupture of membranes (PROM), chorioamnionitis, fetal bradycardia and preterm delivery within 48 h of amniodrainage. RESULTS: Seventy-four consecutive women had 134 rapid amniodrainage procedures during the study period. Four procedures were excluded because the women were already in labor at the time of amniodrainage and they delivered within 48 h of the procedure. The final database therefore consisted of 70 patients with 130 procedures. Sixty-two percent (80/130) of the procedures were performed for the treatment of twin-twin transfusion syndrome (TTTS). There were altogether four procedure-related complications (3.1%; 95% CI, 1.0-8.0%). Three of them occurred in the TTTS group (3/80 procedures, 3.8%; 95% CI, 1.0-11.0%): one case each of placental abruption, PROM and fetal bradycardia. One PROM occurred in the non-TTTS group (1/50 procedures, 2.0%; 95% CI, 0-11.0%). In both cases of PROM the women presented in labor. CONCLUSIONS: Rapid amniodrainage using a vacuum wound-drainage system is safe and efficient to treat severe polyhydramnios, with a 3.1% complication rate.

Amniocentesis↗
PubMed2003

The ultrasound assessment of adipose tissue deposition in fetuses of "well controlled" insulin-dependent diabetic pregnancies.

OBJECTIVE: To assess differences in adipose deposition in fetuses from normal pregnancies and women with diabetes. RESEARCH DESIGN AND METHODS: The study group consisted of 15 well controlled insulin-dependent women with diabetes and 16 controls with a normal glucose. Ultrasound measurements were taken of subcuticular tissue thickness at the abdominal and suprascapular level at 31 and 37 weeks gestation. Triceps and subscapular skinfold thickness were also measured at birth. RESULTS: Gestational age at delivery and birthweights were not significantly different. At 31 weeks, fasting glucose levels were 5.0 +/- 1 mmol/l for diabetic vs. 3.3 +/- 0.3 mmol/l for controls (P < 0.01), post-prandial 5.6 +/- 0.4 vs. 5.1 +/- 0.3 mmol/l (P < 0.01). At 37 weeks, they were 4.6 +/- 0.2 mmol/l vs. 3.8 +/- 1.1 mmol/l (P < 0.01) and 6.0 +/- 0.6 mmol/l vs. 5.3 +/- 0.3 mmol/l (P < 0.01). Abdominal and suprascapular subcuticular thickness were 4.4 +/- 0.1 mm vs. 3.7 +/- 0.1 mm (P < 0.05) and 4.3 +/- 0.2 mm vs. 3.5 +/- 0.2 mm (P < 0.05) at 31; 5.6 +/- 0.2 mm vs. 4.8 +/- 0.1 mm (P < 0.05) and 5.4 +/- 0.2 mm vs. 4.4 +/- 0.1 mm (P < 0.05) at 37 weeks. At birth, triceps and suprascapular skinfolds were 4.7 +/- 0.1 mm vs. 4.1 +/- 0.1 mm (P < 0.05) and 4.7 +/- 0.2 mm vs. 3.8 +/- 0.1 mm (P < 0.01). CONCLUSION: Adipose tissue disposition is increased in fetuses of women with well-controlled diabetes. This may be a reflection of higher maternal glucose levels in these women and may explain why even well-controlled diabetic pregnancies are at risk of macrosomia.

Adipose Tissue↗
PubMed2001

Rapid and radical amniodrainage in the treatment of severe twin-twin transfusion syndrome.

We have evaluated the role of a rapid and radical method of amniodrainage in the treatment of severe twin-twin transfusion. The outcome of 15 patients with severe twin-twin transfusion for which a amniodrainage was performed by means of a vacuum bottle system was compared with the outcome of 15 patients with a similar condition, matched for gestational age at the time of the initial procedure and drained using a standard procedure. In the study group the amniodrainage ended when no amniotic fluid could be aspirated, whereas the women in the standard group were drained with a syringe system and the fluid was removed until the deepest amniotic fluid pool was <8 cm. At the initial procedure, the mean volume of amniotic fluid drained was significantly (p<0.05) higher (3252 vs 2153 ml) and the length of the procedure significantly (p<0.001) shorter (21 vs 41 min) in the study group than in the standard group. The mean post-procedure amniotic fluid index was significantly (p<0.001) smaller (2.9 vs 7.7 cm) after radical amniodrainage than after the standard amniodrainage. The mean number of procedures was significantly (p<0.001) lower (1.5 vs 5.6) in the study group compared to the standard group. In the study group the mean placental thickness increased significantly (p<0.001) from 9 mm before the procedure to 49 mm after, and the overall perinatal survival rate was 80% and the proportion of pregnancies with at least one survivor was 93%. The present data indicate that early, rapid and radical amniodrainage is an effective and low-cost therapy for severe twin-twin transfusion syndrome. Compared to the standard amniodrainage technique it also appears to reduce the need for multiple procedures.

Amnion↗
PubMed1999

Using fetal nuchal translucency to screen for major congenital cardiac defects at 10-14 weeks of gestation: population based cohort study.

OBJECTIVES: To examine the utility of measuring fetal nuchal translucency thickness in screening for major defects of the heart and great arteries at 10-14 weeks of gestation. DESIGN: Population based cohort study. SUBJECTS: 29 154 singleton pregnancies with chromosomally normal fetuses at 10-14 weeks of gestation. SETTING: Fetal medicine centre in London. MAIN OUTCOME MEASURE: Prevalence of major defects of the heart and great arteries. RESULTS: Of 50 cases with major defects of the heart and great arteries (prevalence 1.7 per 1000 pregnancies) 28 (56%, 95% confidence interval 42% to 70%) were in the subgroup of 1822 pregnancies with fetal nuchal translucency thicknesses above the 95th centile of the normal range. The positive and negative predictive values for this cut off point of nuchal translucency thickness were 1.5% and 99.9% respectively. CONCLUSIONS: Measurement of fetal nuchal translucency thickness-traditionally used to identify fetuses at high risk of aneuploidy-at 10-14 weeks of gestation can identify a large proportion of fetuses with major defects of the heart and great arteries.

Adolescent↗
PubMed1999

First trimester screening for fetal abnormalities.

The debate over the application of nuchal translucency measurement in Down's syndrome screening is still unresolved in some clinicians' minds. Although different authors report a range of sensitivities for Down's syndrome, none question the validity of the association between increased nuchal translucency and fetal aneuploidy. The published literature reveals a lack of congruence over a standard, reproducible method for measuring nuchal translucency. Only with the adoption of uniform methodology, and the establishment of international standards for nuchal translucency measurement, is the true potential of this test likely to be realized. The increasing use of first trimester ultrasound has focused attention on the value of this investigation in confirming fetal viability, estimation of gestational age, and screening for congenital abnormality. This review summarizes the role of ultrasound and maternal serum biochemistry in first trimester screening.

Congenital Abnormalities↗
PubMed1998

Biochemical analyses of mesenchymal fluid in early pregnancy.

OBJECTIVE: Our purpose was to compare the biochemical composition of the fluid contained in pathologic and physiologic cavities in early pregnancy. STUDY DESIGN: The level of urea, creatinine, electrolytes, enzymes, total protein, and alpha-fetoprotein and the affinity of alpha-fetoprotein for concanavalin A Sepharose was measured in samples of vesicular fluid from complete (n=2) and partial (n=1) mole, nuchal fluid (n=4), and cystic hygroma fluid (n=4). For comparison samples of maternal serum (n=32), amniotic fluid (n=32), coelomic fluid (n=15), and fetal blood (n=13) were obtained from normal pregnancies at 10 to 16 weeks' gestation. RESULTS: Urea concentration was lower, whereas sodium, potassium, and total protein concentrations were higher in vesicular fluid than in amniotic and coelomic fluid. Urea, creatinine, sodium, potassium, chloride, and beta2-microglobulin concentrations did not vary between nuchal or cystic hygroma fluid and amniotic fluid or fetal serum. The concentration of total protein in nuchal and hygroma fluid was significantly lower than in fetal serum and significantly higher than in amniotic fluid. The amniotic fluid contained extremely high tau-glutamyltransferase concentration compared with the other fluids and fetal serum. Alkaline phosphatase and amylase were not detectable in coelomic fluid, fetal serum, or nuchal and hygroma fluid. The nuchal and hygroma fluid composition was similar except for total protein and alpha-fetoprotein concentrations, which were significantly higher in nuchal than in hygroma fluid. The vesicular fluid from the partial mole, fetal serum, and nuchal and hygroma fluid contained extremely high alpha-fetoprotein concentrations, which were significantly higher that those found in amniotic fluid. In complete mole alpha-fetoprotein molecules were of the yolk sac type, whereas they were of the liver type in nuchal and hygroma fluid. CONCLUSIONS: The composition of vesicular fluid in complete mole reflects a possible origin from the maternal plasma, yolk sac, and trophoblast, whereas the composition of nuchal and cystic hygroma fluid suggests a leakage from the fetal circulation.

Alkaline Phosphatase↗
PubMed1998

Endoscopic laser coagulation in the management of severe twin-to-twin transfusion syndrome.

OBJECTIVE: To assess the clinical effectiveness of endoscopic laser coagulation of placental vessels in the treatment of severe transfusion syndrome. DESIGN: Prospective study. SETTING: Three referral centres for the management of twin-to-twin transfusion syndrome. POPULATION: One hundred and thirty-two pregnancies complicated by severe twin-to-twin transfusion syndrome, reflected by polyhydramnios and enlarged bladder of one twin and oligoanhydramnios and collapsed bladder of the other twin, presenting before 28 weeks of gestation. METHODS: Prospective collection of data on pre-procedure assessment, the procedure and the follow up were collected prospectively. Laser coagulation of placental vessels crossing the intertwin membrane on the chorionic surface under sono-endoscopic guidance, followed by amniodrainage. MAIN OUTCOME MEASURES: Maternal and pregnancy complications, perinatal death and morbidity were assessed over the last five years with follow up of survivors. RESULTS: Endoscopic laser was carried out at a median gestation of 21 weeks. The total number of surviving infants was 144 (55%) and there was at least one survivor in 97 cases (73%). At a minimum age of one year neurological handicap was suspected in six survivors (4.2%). CONCLUSIONS: The results of this multicentre study are similar to those in our original report on the first 45 cases. In comparison with serial amniodrainage, the survival rate may be similar, but the handicap rate in survivors appears much lower. This study stresses the need for a prospective study comparing these two techniques.

Endoscopy↗
PubMed1997

Abnormalities of the heart and great arteries in first trimester chromosomally abnormal fetuses.

Pathological examination of the heart and great arteries was performed in 112 chromosomally abnormal fetuses after surgical termination of pregnancy at 11-16 weeks of gestation. The chromosomal abnormalities were diagnosed by chorion villus sampling which was carried out because screening of the pregnancies by a combination of maternal age and fetal nuchal translucency thickness at 10-14 weeks of gestation identified them as being at increased risk. The group consisted of 60 fetuses with trisomy 21, 29 with trisomy 18, 17 with trisomy 13 and 6 with Ullrich-Turner syndrome. The most common cardiac lesion seen in trisomy 21 fetuses was an atrioventricular or ventricular septal defect. Trisomy 18 was associated with ventricular septal defects and/or polyvalvular abnormalities. In trisomy 13, there were atrioventricular or ventricular septal defects, valvular abnormalities, and either narrowing of the isthmus or truncus arteriosus. Ullrich-Turner syndrome was associated with severe narrowing of the whole aortic arch. In all four groups of chromosomally abnormal fetuses, the aortic isthmus was significantly narrower than in normal fetuses and the degree of narrowing was significantly greater in fetuses with high nuchal translucency thickness. It is postulated that narrowing of the aortic isthmus may be the basis of increased nuchal translucency thickness in all four chromosomal abnormalities.

Abnormalities, Multiple↗
PubMed1997

Lethal congenital arthrogryposis presents with increased nuchal translucency at 10-14 weeks of gestation.

This study examines the ultrasonographic features of congenital lethal arthrogryposis. In 27 cases of arthrogryposis diagnosed in the second and third trimesters there was severe bilateral talipes, fixed flexion deformities of the wrists and elbows and either fixed flexion or extension of the knees. In seven (26%) of the cases there was nuchal edema. In two fetuses with arthrogryposis that were examined at 13 weeks of gestation the nuchal translucency thickness was above the 99th centile of the normal range for crown-rump length. In three other women with previously affected pregnancies, ultrasound examination at 10-14 weeks demonstrated normal fetal nuchal translucency thickness and none of these fetuses were subsequently found to have arthrogryposis. These findings suggest that lethal arthrogryposis, which is usually diagnosed by the demonstration of multiple joint contractures during the second or third trimester of pregnancy, may present as increased nuchal translucency thickness at 10-14 weeks of gestation.

Adult↗
PubMed1997

Fetal testing in intra-uterine growth retardation.

There are three major issues that remain subject to debate in relation to fetal growth retardation: (1) Which method should be used to identify the affected population? (2) Which biophysical test(s) is most appropriate to assess the pregnancy? (3) Which factors are important when considering elective delivery? This review summarizes recent studies investigating the efficacy and accuracy of tests used for the identification and surveillance of pregnancies at risk of growth retardation, and discusses the importance of gestational age in the decision for or against intervention.

Cordocentesis↗
PubMed1996

Evolution of sonographic findings in a fetus with agenesis of the urethra, vagina, and rectum.

In a 12-week gestation fetus, routine ultrasound examination suggested dilated loops of bowel. Repeat scans at 13 and 15 weeks showed normal growth but persistence of bowel dilatation. At 20 weeks there was megacystis, hyperechogenic bowel, ascites, and oligohydramnios. The diagnosis of cloacal abnormality was suspected and the parents chose to have pregnancy termination. Post-mortem examination demonstrated female pseudohermaphroditism with agenesis of the urethra, vagina, and rectum.

Adolescent↗
PubMed1996

Abnormalities of the heart and great arteries in chromosomally normal fetuses with increased nuchal translucency thickness at 11-13 weeks of gestation.

Pathological examination of trisomic fetuses with increased nuchal translucency thickness at 11-13 weeks of gestation demonstrated a high prevalence of cardiac defects and abnormalities of the great arteries. This study reports the pathological findings observed from the examination of the heart and great arteries of 21 chromosomally normal fetuses with increased nuchal translucency. In 19 of the 21 cases there were abnormalities; the commonest was narrowing of the aorta at the level of the isthmus and immediately above the aortic valve. This finding is different from that in case of trisomy 21, where narrowing of the isthmus is associated with an increased diameter of the aortic valve. These findings suggest that abnormalities of the heart and great arteries may be implicated in the pathogenesis of increased nuchal translucency not only in trisomic fetuses but also in chromosomally normal fetuses. It can be implied that increased nuchal translucency thickness at 10-14 weeks of gestation may prove to be a useful marker for the identification of fetal cardiac abnormalities.

Coronary Vessel Anomalies↗
PubMed1996

Fetal heart rate and umbilico-placental Doppler flow velocity waveforms in early pregnancies with a chromosomal abnormality and/or an increased nuchal translucency thickness.

Fetal heart rate, umbilical artery pulsatility index, end-diastolic flow, nuchal translucency thickness and placental thickness were recorded in 250 women with a viable singleton pregnancy undergoing chorionic villous sampling for fetal karyotyping at 11-14 weeks of gestation. The fetal karyotype was normal in 210 cases and abnormal in 40, including 21 with trisomy 21, 13 with trisomy 18, three with triploidy, two with monosomy X and one with trisomy 13. A total of 52 fetuses with a normal karyotype had a nuchal translucency > or = 3 mm and were considered separately. There was a stable and significant increase in the mean fetal heart rate in trisomy 21 pregnancies compared to controls. No significant difference was found for the other variables between the groups. In chromosomally normal fetuses with an increased nuchal thickness, the development of fetal heart rate and compliance of the umbilico-placental circulation were within the normal ranges. Some fetuses with trisomy 18 or triploidy had an increased resistance to blood flow in the umbilical artery, which was probably due to abnormal placental development.

Blood Flow Velocity↗
PubMed1995

Preliminary experience with endoscopic laser surgery for severe twin-twin transfusion syndrome.

BACKGROUND: In monozygotic twin pregnancies, there are placental vascular communications between the two fetuses. In 15 percent of such pregnancies there is an imbalance in net blood flow between the twins, resulting in the twin-twin transfusion syndrome. The recipient twin may have severe hydramnios during the second trimester of pregnancy, and there is a high risk of perinatal death and cerebral palsy in survivors. This condition can now be treated by endoscopic coagulation of the vascular anastomoses responsible for fetofetal transfusion with a neodymium:yttrium-aluminum-garnet (Nd: YAG) laser. METHODS: We performed intrauterine surgery in 45 pregnant women carrying twins at 15 to 28 weeks of gestation (median, 21); in each case there was severe hydramnios in one fetus due to the twin-twin transfusion syndrome. With the use of local anesthesia and continuous ultrasound visualization, a rigid fetoscope 2 mm in diameter, housed in a 2.7-mm cannula, was introduced transabdominally into the amniotic cavity of the recipient twin. A systematic search was made for all vessels approaching or crossing the membrane between the twins, and these were coagulated with an Nd:YAG laser by means of a fiber in the side arm of the cannula. RESULTS: Coagulation of the communicating vessels was successful in all cases. The total number of fetuses who survived to delivery was 48 (53 percent), and the number of pregnancies with at least 1 survivor was 32 (71 percent). Among the live-born infants, the median gestational age at delivery was 35 weeks (range, 25 to 40), and the median birth weight was 2098 g (range, 550 to 4252). The median interval between the endoscopic laser procedure and delivery was 14 weeks (range, 0 to 21). All the survivors were developing normally at a median age of 12 months (range, 2 to 24). CONCLUSIONS: Our preliminary experience suggests that the twin-twin transfusion syndrome can be treated effectively by endoscopic laser coagulation of the communicating placental vessels.

Endoscopy↗