Maternal serum anti-D antibody concentration and assessment of rhesus isoimmunisation.
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Anemia↗
Biomedical subjects
C H Rodeck
Publications and source records attributed to C H Rodeck.
Neonatal alloimmune thrombocytopenia due to anti-P1A1 (anti-HPA-1a): importance of paternal and fetal platelet typing for assessment of fetal risk.
Neonatal alloimmune thrombocytopenia (NAIT), which usually involves sensitization to P1A1 (HPA-1a), may have devastating complications for the fetus. These may be prevented by antenatal treatment of severe cases with either maternally administered high-dose gamma-globulin and/or repeated intrauterine platelet transfusions. Determination of the paternal platelet phenotype is useful for counseling parents who have had one or more affected pregnancies. This report of an unaffected pregnancy in a woman with a history of previous pregnancies complicated by NAIT illustrates the role of paternal and fetal platelet phenotyping in managing existing pregnancies at risk of NAIT.
Adult↗
Mimicking low amniotic pressure by chronic pharyngeal drainage does not impair lung development in fetal sheep.
OBJECTIVE: The etiology of oligohydramnios-related pulmonary hypoplasia is not understood but is known to involve chronic lung liquid loss. We tested the hypothesis that low amniotic pressure in oligohydramnios disturbs the normal tracheal-amniotic pressure gradient to increase lung liquid loss and impair lung development. STUDY DESIGN: Chronic pharyngeal catheterization with drainage to the exterior was used in 15 fetal sheep to mimic reduced amniotic pressure at the upper airway in the presence of normal amniotic fluid volume. RESULTS: Pharyngeal pressures relative to amniotic pressures were negative in all drained fetuses (mean +/- SE -3.0 +/- 0.6 mm Hg), in contrast to positive pressures in controls (0.7 +/- 0.1 mm Hg). There was no significant difference in lung weight or deoxyribonucleic acid relative to body weight, or in lung morphometry, between 10 fetuses drained for 10 to 21 days and their control cotwins. CONCLUSION: Mimicking low amniotic pressure in the upper airway by chronic fetal pharyngeal drainage does not impair lung development in fetal sheep.
Amniotic Fluid↗
Cystic lesions of the fetal kidney: diagnosis and prediction of postnatal function by fetal urine biochemistry.
Fetal urine was aspirated under ultrasound control from 21 large cystic renal masses in 18 pregnancies of 20 to 35 weeks gestation. None were associated with bladder or ureteric dilatation. At postnatal investigation, 12 kidneys were demonstrated to be hydronephrotic (5 with no or poor function) and 9 multicystic. Urinary concentrations of sodium (Na+), calcium (Ca++), and phosphate (PO4--) were significantly higher in the multicystic group than in the hydronephrotic, whereas urea and creatinine levels were lower. Determination of urinary PO4-- enabled differential diagnosis with no false-positive or false-negative cases. Among hydronephrotic kidneys, no biochemical parameter accurately predicted postnatal function, although creatinine was increased in all three nonfunctioning kidneys. In hydronephrotic kidneys, urinary Na+ concentration increased with advancing gestational age (r = .66; P < .02), suggesting that the duration of hydronephrosis has a negative effect on renal function.
Calcium↗
Mononuclear phagocyte assays, autoanalyzer quantitation and IgG subclasses of maternal anti-RhD in the prediction of the severity of haemolytic disease in the fetus before 32 weeks gestation.
In 40 cases of haemolytic disease of the fetus due to RhD immunization where the fetus required intrauterine transfusion, fetal packed cell volume was compared with the following parameters of maternal anti-D: (a) concentration, (b) IgG subclass, (c) activity in a macrophage binding assay, and (d) activity in a monocyte antibody-dependent cell mediated cytotoxicity (ADCC) assay. The anti-D concentration exceeded 4 iu/ml in all cases, correctly indicating the risk of haemolytic disease. A relationship between IgG subclass composition of the anti-D and severity of anaemia was not observed; IgG1, IgG3 and IgG1 + 3 antibodies were all detected. The ADCC assay gave the best correlation between assay results and fetal packed cell volume; high results correctly indicated fetal anaemia in 95% of cases. Macrophage binding assay results were only considered as high in 70% of cases. Overall, these results indicate that serological tests and bioassays in highly immunized mothers may not generate any information that proves more useful than ultrasonography and their previous obstetric history.
Antibody-Dependent Cell Cytotoxicity↗
Fetal breathing movements in oligohydramnios are not increased by aminoinfusion.
OBJECTIVE: To determine whether fetal breathing movements (FBM) in pregnancies with oligohydramnios change with restoration of amniotic fluid volume. DESIGN: A prospective experimental study. SETTING: Fetal Medicine Unit, tertiary referral hospital. SUBJECTS: 16 women with singleton pregnancies complicated by severe oligohydramnios. INTERVENTIONS: Restoration of amniotic fluid volume by transabdominal amnioinfusion. Controls comprised pregnancies in which infused fluid leaked vaginally, so that oligohydramnios was not corrected. MAIN OUTCOME MEASURES: Change in total breathing movements, change in FBM incidence derived from 40 min recordings immediately before and after amnioinfusion. RESULTS: There was no significant difference in the change in total breathing movements or in the change in incidence of FBM between the 10 pregnancies in which amniotic fluid volume was restored, and the other six in which fluid leaked after infusion and volume was not restored. In both groups, there was no significant change with infusion in number of FBM (mean change -72, 95% CI -218 to +74 in the fluid-retained group and -64, 95% CI -273 to +145 in the fluid-leaked group) and incidence of FBM (median change -2.5%, range -27 to +10 in the fluid retained group and -4.5%, range -34 to +15 in the fluid-leaked group). CONCLUSIONS: This study suggests that restitution of amniotic fluid volume in human pregnancies complicated by severe oligohydramnios does not acutely alter the incidence of FBM. These data support an increasing literature suggesting that impairment of fetal breathing is not the mechanism for oligohydramnios-related pulmonary hypoplasia.
Amnion↗
Normal amniotic pressure throughout gestation.
OBJECTIVE: To characterize amniotic pressure (AP) in pregnancies with normal amniotic fluid volume. DESIGN: Observational study, mainly cross-sectional. SETTING: Fetal medicine unit within a tertiary referral hospital. SUBJECTS: Patients undergoing transamniotic invasive procedures in whom amniotic fluid volume was subjectively assessed as normal on ultrasound. Those beyond 16 weeks with a deepest vertical pool on ultrasound less than 3.0 or greater than 8.0 cm were excluded. Overall 194 pregnancies were studied on 232 occasions between 7 and 38 weeks gestation. INTERVENTIONS: Manometry readings referenced to the top of the maternal abdomen were obtained via a fluid-filled line from the needle hub and either connected to a pressure transducer (n = 190) or held vertically against a ruler (n = 42). MAIN OUTCOME MEASURES: AP in mm Hg, AP corrected for gestational age (z scores), semi-quantitative ultrasonic indices of amniotic fluid volume, clinical variables. RESULTS: AP in singleton pregnancies increased with advancing gestation (P less than 0.001), and the sigmoid-shaped regression curve plateaued in the mid-trimester. AP z scores were not influenced by volume-related phenomena such as twin gestation, the deepest vertical pool, or amniotic fluid index, nor by maternal age, parity, gravidity, fetal sex, or subsequent spontaneous preterm delivery. CONCLUSIONS: These findings suggest that AP is not principally determined by intrauterine volume. We speculate that AP, which reflects change in uterine tension as a function of radius, may instead be determined by gestation-specific anatomical and hormonal influences on gravid uterine musculature. A reference range for AP has been constructed for use in amnioinfusion and amnioreduction procedures.
Amniotic Fluid↗
Fetal urine biochemistry: an index of renal maturation and dysfunction.
OBJECTIVE: To construct a reference range for fetal urinary sodium, potassium, urea, creatinine, calcium and phosphate with gestation and to assess to what extent these biochemical indices are modified in fetuses with lower urinary tract obstruction. DESIGN: Prospective descriptive study. SETTING: Royal Postgraduate Medical School London. SUBJECTS: 24 women between 17 and 35 weeks gestation with an ultrasound diagnosis of fetal lower urinary tract obstruction, with or without renal dysplasia and a control group of 26 women between 16 and 33 weeks gestation with normal amniotic fluid volume and fetal anatomy. INTERVENTIONS: Fetal urine samples (1-100 ml) were aspirated from the control fetuses either before termination of pregnancy (n = 9) or at the time of intrauterine transfusion for Rh alloimmunization (n = 17). The fetuses with obstructive uropathy had urine samples aspirated on one occasion (n = 14) or serially (n = 10). MAIN OUTCOME MEASURES: Relation between urine biochemistry and renal damage ascertained clinically or at postmortem. RESULTS: In the control group, urinary sodium and phosphate decreased and creatinine increased significantly with gestational age, consistent with increasing fetal glomerular filtration rate and progressive maturation of tubular function. Urinary sodium and calcium were significantly higher in fetuses with renal dysplasia compared with those with lower urinary tract obstruction but normal renal histology or normal clinical outcome. Serial urinary samples from fetuses with obstructive uropathy showed more pronounced deviation from the normal with increasing gestation in all fetuses with renal dysplasia. The highest sensitivity in the detection of renal dysplasia was shown by urinary calcium (100%) whereas urinary sodium showed the best specificity (80%). CONCLUSION: Renal damage is the direct effect of urinary obstruction, rather than an association so that treatment should start as soon as possible. Urinary biochemistry may be helpful in the management of these patients.
Electrolytes↗
The importance of serial biophysical assessment of fetal wellbeing in gastroschisis.
OBJECTIVE: To review antenatal and intrapartum assessment of pregnancies complicated by gastroschisis. DESIGN: Retrospective descriptive study. SETTING: University College Hospital, London. SUBJECTS: 24 consecutive cases of gastroschisis between 1986 and 1991. RESULTS: The gestational age at sonographic diagnosis was 20.3 weeks (SD 6.77) and at birth was 36.5 weeks (SD 2.06). There were 21 live births, all with good surgical outcome. There were 16 vaginal deliveries and eight caesarean sections. The elective sections were for oligohydramnios and dilated bowel (1) and clinically suspected growth retardation (1); the intrapartum caesarean sections were for fetal distress (4) and premature breech presentation (2). There were six with dilated gut on ultrasound; one of these ended in a stillbirth. There was a significant association between gut dilatation and caesarean section for fetal distress (P = 0.004). There was also a significant association between meconium staining and fetal distress (P = 0.021). Of these babies, 46% were < or = third centile for corrected birth weight. CONCLUSIONS: While half of the babies with gastroschisis were small for gestational age at birth, reliable antenatal prediction of birth weight is difficult. Gut dilatation may be an indicator of either antenatal or intrapartum fetal distress, but does not correlate with poor neonatal surgical outcome. We suggest close antenatal surveillance of fetal wellbeing in all cases of gastroschisis because, in addition to growth retardation, many show some evidence of fetal distress and 12.5% end in stillbirth, even when appropriately grown.
Abdominal Muscles↗
Relief of presumed compression in oligohydramnios: amnioinfusion does not affect umbilical artery Doppler waveforms.
The suggestion that amnioinfusion improves umbilical artery Doppler indices of downstream resistance in oligohydramnios by relieving cord compression was investigated by obtaining waveforms before and immediately after amnioinfusion in 16 pregnancies with severe oligohydramnios. There was no significant difference in the change in umbilical artery pulsatility index (PI) between 11 pregnancies in which amniotic fluid volume was restored (mean delta PI = -0.07, 95% confidence interval -0.17 to +0.07), and 5 pregnancies in which immediate vaginal leakage of infused fluid prevented restitution of amniotic fluid volume. Fetal heart rate did not change significantly in either group. End-diastolic frequencies did not return with restitution of amniotic fluid volume in the 2 pregnancies in which they were absent before infusion (absent in 1, reverse in 1). This study suggests that restitution of amniotic fluid volume in human pregnancies complicated by severe oligohydramnios does not acutely alter the umbilical artery PI.
Amnion↗
Ethical dilemmas in fetal medicine.
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England↗
Fetal therapy.
In the past year, the results of the European trial comparing chorionic villus sampling and amniocentesis have been published, supporting the findings of the Canadian Collaborative Study of an increased risk associated with chorionic villus sampling. The reporting of an increase in limb reduction abnormalities with chorionic villus sampling before 9 weeks has made us review our current practice. Other developments covered by this review include the management of mild cerebral ventriculomegaly, the treatment of tachyarrhythmias, and developments in fetal surgery. Throughout, the needs for continued collaboration, pooling of data, and the formation of international registers to extend the database from which both doctors and patients may benefit are highlighted.
Amniocentesis↗
Preinduction cervical assessment by Bishop's score and transvaginal ultrasound.
In this pilot study, 50 patients underwent preinduction cervical assessment by digital Bishop Score (BS) and transvaginal ultrasonography. The BS was lower in 7 patients requiring caesarean section than in 43 delivered vaginally (P = 0.017). Of seven ultrasound parameters examined, six (cervical length, width, dilatation, application and position and lower segment thickness) were similar in both groups. Cervical angle, however, was more acute in those delivered abdominally than vaginally (median = 60 degrees and 90 degrees, respectively, P = 0.002). Posterior cervical angle was more accurate than BS in predicting vaginal delivery (Kappa = 0.48 versus 0.21). Patient discomfort was significantly less with transvaginal ultrasound than digital examination. Combining posterior cervical angle greater than 70 degrees and BS greater than 5 yielded the best accuracy in predicting successful induction of labour (sensitivity = 88%, specificity = 100%, Kappa = 0.68).
Adult↗
Women's choices for fetal chromosome analysis.
Five hundred and eighty women aged 35 or more at the expected date of delivery were offered the chance to join the MRC trial comparing CVS and amniocentesis at Queen Charlotte's Hospital. After a 1 h non-directive counselling session, they were asked to choose between having no test, having amniocentesis, or joining the trial in the hopes of having CVS (or in some cases having CVS outside the trial). The majority of women chose to have some test, and CVS was a more popular choice than amniocentesis.
Adult↗
Extraction of DNA from amniotic fluid cells for the early prenatal diagnosis of genetic disease.
Ten-ml samples of amniotic fluid were taken from pregnancies being terminated at 8-14 weeks' gestation. DNA was extracted from the amniotic cells by sequential centrifugation and analysed using the polymerase chain reaction (PCR). Fifteen samples were analysed for evidence of maternal contamination using Mfd5 oligonucleotide primers for repeat polymorphisms. Ten amniotic fluid samples were tested for the Delta-F508 deletion characteristic of cystic fibrosis to demonstrate a diagnostic application for the technique. In each case, DNA extracted from fetal tissue from the same pregnancy was included in the controls. In 14 of the 15 cases tested with the Mfd5 primers, both the amniotic fluid DNA and the fetal DNA showed no evidence of contaminating DNA. In one case, neither the amniotic fluid cells nor the fetal cells yielded results. In nine of the ten cases tested with the Delta-F508 primers, the amniotic fluid cell DNA provided accurate information about the genetic status of the fetus; in the tenth, the fetal DNA failed to amplify. The results indicate that adequate DNA can be extracted from amniotic fluid from 8 weeks' gestation onward and these samples are suitable for prenatal diagnosis using PCR.
Adult↗
Further predictors of renal dysplasia in fetal obstructive uropathy: bladder pressure and biochemistry of 'fresh' urine.
Urine was aspirated on two consecutive days from the dilated bladder of nine fetuses with lower urinary tract obstruction. Gestational age ranged from 17 to 35 weeks. Renal dysplasia was diagnosed histologically in four fetuses, whereas the other five had normal renal histology or only partial dysplasia. Urinary sodium (Na+) and osmolality (Osm) decreased significantly in the second urine sample 1 day after bladder emptying (median decrease: Na+ = -11.3 per cent; Osm = -13.3 per cent). Although there were no significant differences between fetuses with or without renal dysplasia, normalization of an initially raised urine Na+ concentration occurred at the second sample in a fetus with partially normal renal histology, thus correcting a false-positive diagnosis of dysplasia. Bladder pressure was measured at the time of the first urine sampling in seven fetuses and in a further eight with bladder outlet obstruction undergoing a single urine aspiration at 18-28 weeks. Bladder pressure was increased above the reference range in 8 of 15 fetuses with urinary obstruction, but there was no correlation between pressure and the degree of impairment of renal function. Although no conclusive clinical guidelines can be drawn from this study for the evaluation of fetal renal function, these findings suggest that, in lower urinary tract obstruction, tubular reabsorption is impeded by the standing pressure in the urinary tract and that improvement of renal function may occur following relief of obstruction.
Electrolytes↗
Trophoblast from anembryonic pregnancy has both a maternal and a paternal contribution to its genome.
In a series of 14 anembryonic pregnancies, deoxyribonucleic acid from trophoblast was examined with locus-specific minisatellite probes. It was found in each case that trophoblast from anembryonic pregnancy has both a maternal and a paternal contribution to its genome. This means that although anembryonic pregnancy shares characteristics with complete hydatidiform mole and androgenetic development in the mouse in that there is no embryo, it does not arise by the same genetic process. Of three anembryonic pregnancies that were successfully karyotyped, two had normal female 46,XX chromosome constitutions and one had an abnormal 47,XX + 16 complement. The sex of the trophoblast in each anembryonic pregnancy was determined with a deoxyribonucleic acid probe with Y-specific bands. A male-to-female ratio of 6:8 was found, which is not significantly different from normal.
Chromosome Mapping↗
Management of immune haemolytic disease in the fetus.
Although Rh alloimmunization has been successfully reduced in frequency and severity since the implementation of Rh immune globulin, cases still occur. The management of affected pregnancies requires the efforts of a team which includes obstetrics/fetal medicine, the blood transfusion service, haematological support, nursing assistance and neonatology. The aim of antenatal management is to predict whether or not the fetus is severely affected, to correct the fetal anaemia and to deliver the baby at the optimal time. The management has improved markedly with the introduction of high-resolution real-time ultrasound, fetal blood sampling, intravascular fetal blood transfusion and/or intraperitoneal transfusion and meticulous fetal surveillance. With appropriate and timely management in severely alloimmunized patient, the survival rate of affected fetuses in some centres is now about 90%. There is still a need for research into new methods of treatment such as high dose intravenous immunoglobulin, which might non-invasively diminish fetal red cell destruction. Due to the reduced frequency of severe disease, regionalized treatment centres are essential in order to maximize the experience and efficiency of the management teams.
Blood Group Antigens↗