Total uterine artery blood volume flow rate in nulliparous women is associated with birth weight and gestational age at delivery.

OBJECTIVES: To investigate the relationship between total uterine artery blood volume flow rate (TVFR) and birth weight and gestational age at delivery, and to establish normal ranges of TVFR throughout pregnancy. METHODS: This was a prospective cohort study of 334 nulliparous women booking antenatal care at University College London Hospital between August 2008 and September 2009. Women underwent a transabdominal ultrasound examination of uterine arteries for measurement of TVFR at 12, 20 and 24 weeks' gestation. Pregnancy outcomes were recorded and linear regression was used to study the relationship between TVFR and gestational age at delivery and birth weight. RESULTS: A total of 551 ultrasound scans were performed. There was a significant, positive correlation between TVFR at 11-13 weeks (TVFR1) and at 22-26 weeks (TVFR3) and birth weight. For every 100-mL/min increase in TVFR1 and TVFR3, there was an increase in birth weight of 45 g and 27 g, respectively. There was also a positive association between TVFR1 and gestational age at delivery, with a 1.4-day increase in gestational age for every 100-mL/min increase of TVFR1. CONCLUSION: Ultrasound measurement of TVFR in the first trimester is significantly associated with both birth weight and gestational age at delivery. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

The relationship between body mass index and mid-arm circumference in a pregnant population.

Our objective was to correlate body mass index (BMI) with mid-arm circumference (MAC) and also to ascertain whether maternal BMI could be calculated from MAC at booking. We approached all Caucasian women who met the inclusion criteria attending the University College Hospital, London between 1 April 1996 and 30 June 1997 and the Rotunda Hospital, Dublin, Ireland between 15 April 2003 and 19 May 2004. A total of 2,912 women agreed to participate in the research. The participants' maternal height and weight were measured. Their BMI was calculated using the formula: BMI = weight (kg) ÷ height (m(2)). The MAC was measured in cm. Statistical analysis was performed using SPSS for Windows version 11 with p < 0.05 as significant. We found that BMI is directly correlated with MAC (r = 0.836) and estimates of BMI may be calculated from the simple equation BMI = MAC ± 2. Alternatively, a MAC of ≥ 27 cm allowed for a detection rate for overweight patients of 75%, with a false positive rate of 15%.

Antenatal screening for Down's syndrome using the Integrated test at two London hospitals.

We carried out an audit of antenatal screening for Down's syndrome using the Integrated test (which provides a single screening result from information collected in the late first and early second trimesters of pregnancy) which was introduced into routine antenatal care at two London hospitals, University College Hospital (UCH) and St Mary's Hospital, in 2003-4. The audit was based on 15,888 women who accepted screening and booked in the first trimester. The Down's syndrome detection rate was 87% (95% confidence interval [CI], 74-95) consistent with an expected detection rate of 89% based on applying the estimates of screening performance of the Serum, Urine and Ultrasound Screening Study (SURUSS) to the maternal age distribution of women who were screened at UCH and St Mary's. The observed false-positive rate was 2.1% (95% CI, 1.9-2.3), compared with an expected of 2.5% for women of the same age. An audit trail (conducted at UCH) indicated that 98% (10,746/10,961) of women accepted integrated screening (2% having a first trimester test) and of these, 94% (10,116) completed both stages of the test. The audit demonstrated that it is feasible to conduct integrated screening within the NHS with a high acceptance rate and a screening performance consistent with that determined from previous research studies.

Local delivery of VEGF adenovirus to the uterine artery increases vasorelaxation and uterine blood flow in the pregnant sheep.

Impaired materno-placental perfusion causes two important obstetric complications, fetal growth restriction and preeclampsia. This study investigated whether adenoviral vector-mediated overexpression of vascular endothelial growth factor (VEGF) in the uterine arteries (UtAs) increases uterine artery blood flow (UBF). First-generation adenovirus vectors (5 x 10(11) particles) containing the VEGF gene (Ad.VEGF-A or -D) or the beta-galactosidase reporter gene (Ad.lacZ) were injected into the UtAs of pregnant sheep (n=6) at 88-102 days of gestation (term=145 days). UBF was measured using Doppler sonography before, and 4-7 days after injection. Mean UBF increased significantly from 233+/-156 (s.d.) ml min(-1) to 753+/-415 ml min(-1) following Ad.VEGF-A injection (P=0.005, n=5); Ad.lacZ infection had no significant effect. Organ bath experiments on uterine arterial sections 4-7 days after injection showed that, compared with Ad.lacZ vessels, Ad.VEGF-A-transduced vessels had a reduced contractile response to phenylephrine (E max 148+/-10.9 vs E max 228.2+/-27.5, P<0.05) but increased relaxation with bradykinin (pD2 (-log EC50) values 9.11+/-0.01 vs 8.65+/-0.11, P<0.05). Injection of Ad.VEGF-A into the UtAs increases UBF by enhancing vasodilatation. This may provide the basis for therapy in pregnancies complicated by uteroplacental insufficiency.

Association of isolated short femur in the mid-trimester fetus with perinatal outcome.

OBJECTIVES: To evaluate the prevalence of fetal isolated short femur in a cohort of women screened for Down syndrome by the integrated test, and to compare the outcome of fetuses with isolated short femur in the mid-trimester with that of fetuses with normal femur length (controls). METHODS: This was a retrospective cohort study of 1262 women booked for antenatal care and delivery at University College London Hospital. All women had integrated testing in the late first and early second trimesters and a detailed anomaly scan in the mid-trimester. All scan reports, screening results and neonatal data were analyzed statistically. RESULTS: The fetal femur was short (< 5(th) percentile) in 5.1% of patients and 4.7% had isolated short femur. In pregnancies with isolated short femur, the birth weight was significantly lower and there were higher rates of small-for-gestational age (SGA) and low birth weight (LBW) infants, compared with controls (P < 0.01). The odds ratios for SGA and LBW in pregnancies with isolated short femur were 3.0 (95% CI, 1.5-5.9) and 2.60 (95% CI, 1.1-6.2), respectively. Isolated short femur was associated significantly with low levels of pregnancy-associated plasma protein-A (P = 0.001). CONCLUSIONS: Isolated short femur in the mid-trimester fetus is associated with fetal growth restriction and SGA. In the context of normal Down syndrome screening and a normal anomaly scan, this marker should be regarded as a predictor for SGA, and fetal growth should be monitored during these pregnancies.

Clinically applicable procedure for gene delivery to fetal gut by ultrasound-guided gastric injection: toward prenatal prevention of early-onset intestinal diseases.

Targeting gene therapy vectors to the fetal intestinal tract could provide a novel means toward prevention of the early postnatal intestinal pathology of cystic fibrosis and other conditions, such as congenital enteropathy, that cause intestinal failure. Among these conditions, cystic fibrosis is by far the most common lethal genetic disease. It is caused by a functional absence or deficiency of the cystic fibrosis transmembrane conductance regulator and manifests in the gut as meconium ileus. Prenatal treatment of genetic disease may avoid early-onset tissue damage and immune sensitization, and may target cells that are less accessible in the adult. We investigated gene transfer to the fetal gut, using a minimally invasive injection technique. First-generation replication-deficient adenoviral vectors encoding the beta-galactosidase gene and transduction-enhancing agents were injected into the stomach of early-gestation fetal sheep (n = 8, 60 days of gestation; term, 145 days) under ultrasound guidance. Reporter gene expression was observed 2 days after injection in the villi of the gastrointestinal epithelia after 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside staining and beta-galactosidase immunohistochemistry of fetal tissues. Expression of beta-galactosidase, as measured by enzyme-linked immunosorbent assay, was enhanced after pretreatment of the fetal gut with sodium caprate, which opens tight junctions, and after adenovirus complexation with DEAE-dextran, which confers a positive charge to the virus. Instillation of the fluorocarbon perflubron after virus delivery resulted in tissue transduction from the fetal stomach to the colon. Using a clinically relevant technique, we have demonstrated widespread gene transfer to the fetal gastrointestinal epithelia.

P-type inositol phosphoglycans in serum and amniotic fluid in active pre-eclampsia.

OBJECTIVES: Abnormal secretion of P-type inositol phosphoglycans (IPG-P) has been described in maternal urine of pre-eclamptic women. The aim of this study was to determine the origin of production of IPG-P. We examined the IPG-P content of maternal and fetal serum, maternal urine and amniotic fluid in both normal pregnancy and pre-eclampsia. DESIGN: Established extraction and bioactivity assay techniques were used to compare total IPG-P levels in serum samples, and a polyclonal-antibody-based ELISA to assay the amniotic fluid and urine samples in matched pairs of women. SUBJECTS: Eleven women with pre-eclampsia requiring caesarean section (subjects), 11 pregnant women requiring elective caesarean section for reasons other than pre-eclampsia (controls). RESULTS: Our data confirm the abnormal level of IPG-P in maternal urine during pre-eclampsia. Moreover, IPG-P levels were higher in umbilical sera than in maternal sera samples. Amniotic fluid as well as urine ELISA results were significantly higher in the pre-eclamptic group compared with normal controls. Total IPG-P bioactivity in serum did not vary between serum compartments in normal pregnancy. Uterine vein IPG-P levels were lower in pre-eclampsia when compared with normal pregnancy. A possible correlation was observed between urine and amniotic fluid levels in normal women. No correlation was observed between measured blood levels and those in urine and amniotic fluid. CONCLUSIONS: It is hypothesized that steady state equilibrium of IPG-P in serum in normal pregnancy is disrupted in pre-eclampsia. Additionally, an abnormal IPG-P sub-fraction, detectable in urine and amniotic fluid, may be present and involved in the pathophysiology of the syndrome, although sites of production of this abnormal form remain unclear.

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.

Prenatal diagnosis of oculocutaneous albinism by electron microscopy of fetal skin.

Oculocutaneous albinism was diagnosed prenatally by electron microscopic examination of fetal skin samples taken during fetoscopy at 20 weeks of gestation. Melanosome development in hair bulb melanocytes progressed no further than stage II, indicating a lack of melanin synthesis. In 4 age-matched control fetuses, numerous stage IV melanosomes, signifying active melanin synthesis, were identified. The diagnosis was confirmed after the pregnancy was terminated at 22 weeks. Examination of the fetal eye showed absence of pigment in the retinal epithelium and uvea at a stage when ocular melanogenesis would normally be active. This study shows that oculocutaneous albinism can be detected in the second trimester using similar techniques to those employed in the prenatal diagnosis of epidermolysis bullosa and ichthyosis.

The inheritance of a Macaca fascicularis red cell antigen detected by CAMPATH-1 antibody.

CAMPATH-1 monoclonal antibody is reactive with human lymphocytes and monocytes and it has been shown to bind to antigens on the red cells of a number of primate species, including Macaca fascicularis. Our study within a closed colony of breeding M. fascicularis monkeys has confirmed this finding, and shown that the antibody identified a single red cell antigen inherited in Mendelian fashion as a dominant character. We have, further, confirmed that the antigen is present on blood lymphocytes, even in animals whose red cells are negative. This CAMPATH-1 antigen can therefore serve as a useful red cell marker in experiments involving bone marrow transplantation or blood transfusion.

On the feasibility of inducing tolerance in man: a study in the cynomolgus monkey.

Our previous work on the in vitro generation of cytotoxic T lymphocytes from the blood of 15-22-week-old fetuses, and on the induction of immunological tolerane in both radiation chimeras and neonatal mice, using T lymphocyte-depleted allogeneic bone marrow cells, has led us to believe that it should be possible to establish red cell chimerism in human fetuses by the infusion of allogeneic adult bone marrow cells. The essential prerequisite appears to be the removal of immunocompetent T lymphocytes from the bone marrow transplant, for new T cells generated from donor stem cells become tolerant to the histocompatibility antigens of the host's thymus and cannot, therefore, cause graft-versus-host disease (GVHD). Such an approach could be used in the treatment of fetuses diagnosed at an early stage as suffering from life-threatening inherited blood disorders. The experiments described here were designed to test this hypothesis in a sub-human primate species, Macaca fascicularis. Twenty-two cynomolgus monkeys received infusions of haploidentical (paternal) bone marrow between days 51 and 95 of gestation. There was no evidence of chimerism in animals inoculated after day 75 from mating. Eight out of 14 fetuses inoculated before day 70 were late intra-uterine deaths, four were hydropic and in one, histological confirmation of GVHD was obtained, indicating that tolerance can be induced at this time, as GVHD can occur only if donor cells survive. The T cell-depletion technique used here did not appear to prevent GVHD.

Relationship between maternal and fetal corticotrophin-releasing hormone-41 and ACTH levels in human mid-trimester pregnancy.

Samples of maternal blood, amniotic fluid and umbilical arterial and venous blood were collected from 11 women at 16-24 weeks of pregnancy. Corticotrophin-releasing hormone-41 (CRH-41) and ACTH were measured by immunoradiometric assay. The mean levels of ACTH were 11 pmol/l in maternal plasma, 12 pmol/l in fetal plasma and 9.7 pmol/l in amniotic fluid. The mean levels of CRH-41 were 1.6 pmol/l in maternal plasma and 0.7 pmol/l in fetal plasma. There was a positive correlation between maternal and fetal plasma CRH-41 and between maternal CRH-41 and ACTH. In fetal plasma there was a weak inverse correlation between CRH-41 and ACTH. This is the first demonstration of CRH-41 in the circulation of the mid-trimester human fetus, but on the basis of the present findings it is not possible to specify the exact source (fetal, placental or maternal).

Pyruvate kinase in fetal plasma and amniotic fluid unsuccessful for the prenatal diagnosis of Duchenne muscular dystrophy.

A specific spectrophotometric assay of muscle-pyruvate kinase (M-PK) was used to measure the activity of this isozyme in fetal muscle, fetal plasma and amniotic fluid at about 17-24 wk of gestational age to assess its predictive value for the prenatal diagnosis of Duchenne muscular dystrophy (DMD). Fetal muscle obtained after termination was found to contain a high M-PK specific activity. No significant activity was detected in amniotic fluid from normal or at-risk fetuses. Pure fetal blood was obtained in utero by fetoscopy; significant plasma levels of M-PK activity were measured in a series of control samples, but at-risk fetal plasma contained no higher levels. We conclude that M-PK is of no use for the prenatal diagnosis of DMD.

Plasma creatine kinase and myoglobin levels, before and after abortion, in human fetuses at risk for Duchenne muscular dystrophy.

Plasma levels of creatine kinase (CK) were measured in 14 abortuses, nine of which were at risk for Duchenne muscular dystrophy (DMD). The plasma CK level was found to be increased in all abortuses, compared with the value obtained by fetoscopy before the termination. The causes of the increase in CK level were found to be 1) method of termination, 2) physical state of the abortus at delivery, 3) delay between delivery of the abortus and taking the blood sample, and 4) site of blood sampling. It is concluded that even under optimum conditions of termination the plasma creatine kinase level of the abortus is significantly raised above the true level; hence, this measurement is not reliable as a guide to the genetic status of the fetus. Cardiac leakage was the main source of the raised plasma CK level in the abortus and this was corroborated by measurement of myoglobin levels.

Unusual lymphangioma observed prenatally in a 45,X fetus.

We present a case of a large frontal lesion, suspected on antenatal ultrasound to be a cephalocele. The cardiac anatomy was abnormal and fetal blood sampling showed a 45,X chromosome constitution. Postmortem examination proved this to be a lymphangioma and confirmed the presence of a cardiac defect. We suggest that this lymphangioma represents an unusual manifestation of monosomy X and discuss the importance of doing chromosome analysis in the presence of such a lesion which is of similar appearance as a cephalocele.

Possible involvement of inositol phosphoglycan-P in human parturition.

Preterm labour is a major cause of neonatal morbidity and mortality but the pathophysiology that underlies preterm labour is unknown. Inositolphosphoglycans (IPGs) comprise a ubiquitous family of putative carbohydrate second messengers and they have been linked to the pathogenesis of various conditions, including diabetes and pre-eclampsia. Studying IPG-P levels in normal and pre-eclamptic pregnancies, we noticed a constant rise of urinary IPG-P levels in all women at the time of delivery. A prospective pilot study of urinary IPG-P levels in 23 non-labouring and labouring women with uncomplicated pregnancies has, therefore, been performed. Levels of urinary IPG-P were significantly higher in labour than in the non-labouring group (P<0.0001). These higher levels have been found in both spontaneous and induced labour. The clinical significance of this observation with particular reference to the onset of labour itself is discussed.

Calcium homeostasis in second trimester fetuses.

The concentrations of ionised calcium ions (Ca++), total calcium, parathyroid hormone, pH, total protein, albumin, sodium, and potassium were measured in paired fetal and maternal blood from pregnancies at 15 to 24 weeks' gestation. Pure fetal blood samples were obtained fetoscopically. The concentrations of fetal ionised calcium ions (n = 26); mean (SD) 1.33 (0.12) mmol/l (5.32 (0.48) mg/100 ml) and those of parathyroid hormone (n = 9); 68 (19) pmol/l (58 (16) micrograms/100 ml) were significantly higher than those of the mothers: 1.18 (0.09) mmol/l (4.7 (0.4) mg/100 ml), and 40 pmol/l (less than 34 micrograms/100 ml), respectively. There was no difference between measured fetal and maternal total calcium, pH, and electrolytes. The fetal total protein and albumin concentrations increased with gestation but were always lower than the equivalent maternal values. The calculated total calcium was 0.23-0.45 mmol/l (0.9-1.8 mg/100 ml) higher in the fetal than in maternal blood from the same pregnancy. There were no fetal arteriovenous differences in ionised calcium ions despite higher venous pH.

Gamma-glutamyl transferase activity in fetal serum, maternal serum, and amniotic fluid during gestation.

Gamma-glutamyl transferase activity was measured in fetal serum, maternal serum, and amniotic fluid in 173 pregnancies from 15 to 40 weeks' gestation. Fetal serum was obtained in the second trimester by fetoscopy and in the third trimester by umbilical cord puncture at caesarian section or vaginal delivery. Enzyme activities in maternal blood (10 IU/1, SD 2) and fetal blood (88 IU/1, SD 20) remained relatively constant throughout gestation, whereas in the amniotic fluid there was a significant decrease at term from the value in the second trimester (p less than 0.001). Electrophoretic separation of the enzyme showed one isoenzyme in the fetal blood and at least two in the amniotic fluid. The fetal isoenzyme had the same mobility as the major isoenzyme in the amniotic fluid.

Rapid processing of fetal skin for prenatal diagnosis by light and electron microscopy.

A method has been developed for rapid processing of fetal skin for prenatal diagnosis of hereditary skin diseases by light and electron microscopy. Fixation, dehydration, embedding, and polymerisation can be achieved in about 5 h. The quality of tissue preservation compares favourably with that produced by slower conventional techniques. This procedure may provoke a wider interest in the potential use of fetal skin biopsy in prenatal diagnosis, especially if identification of structural abnormalities is a feasible alternative to more time consuming biochemical analysis.

Normal reference ranges for biochemical substances relating to renal, hepatic, and bone function in fetal and maternal plasma throughout pregnancy.

Normal reference ranges for sodium, potassium, urea, creatinine, calcium, phosphate, total protein, albumin, bilirubin, alkaline phosphatase, and aspartate transaminase were determined from 344 fetal and maternal plasma samples between 15 and 38 weeks' gestation. Pure fetal blood was obtained by fetoscopy in the second trimester and in the third trimester by umbilical cord puncture at delivery. All biochemical substances were measured by continuous flow (SMAC, Technicon) except albumin, which was measured by turbidimetry (CobasBio, Roche). The resulting data were analysed on an AMDAHL 470A computer and reference ranges covering 2.5 to 97.5 percentiles were defined. Analysis of variance was performed to examine the overall effect of gestational age on the analytes measured and on the changes in the fetal compartment relative to the mothers'. A paired t test was performed to examine how these biochemical substances in fetal plasma related to maternal plasma from the same pregnancy.