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J E Dickinson

Publications and source records attributed to J E Dickinson.

At least 19 recordsLinked to original sources
PubMed2005

The expression of apoptosis related genes in the first trimester human placenta using a short term in vitro model.

Using in vitro model for studying the induction and inhibition of spontaneous apoptosis in human first trimester placental villi, mediated by the free radical scavenger SOD, we have examined the expression of bcl-xL, bax, Caspase-3 and PARP (Poly ADP-ribosyl). An increase in apoptosis was associated with activation of PARP and an increase and activation of Caspase-3. There was no significant change in bcl-x or bax. Therefore bcl-x and bax do not appear to have a significant role in apoptosis in the first trimester in vitro. Cleavage of Caspase-3 rather than transcriptional regulation appears to be the main determinant of Caspase-3 activity in first trimester placental villi.

Apoptosis↗
PubMed2004

The progression of disease stage in twin-twin transfusion syndrome.

OBJECTIVE: To estimate the frequency of progression or regression of disease stage in pregnancies complicated by twin-twin transfusion syndrome (TTTS) managed with non-placental laser techniques. METHODS: A cohort of TTTS pregnancies within the sole perinatal center for the state of Western Australia was examined. All cases of prenatally identified TTTS from 1992 to 2002 were staged at diagnosis (retrospectively prior to 2000, prospectively since). Amnioreduction and septostomy were the principal therapies used. Features associated with progression, regression or stability were identified. RESULTS: During the study period, 71 cases of TTTS were managed. Amnioreduction was performed in 73.2%, with no difference in the median number of procedures by stage (p = 0.178). In 21.1% of cases, TTTS resolved completely with persistent normalization of amniotic fluid volumes after amnioreduction (median number of procedures: 2). Disease resolution was associated with pregnancy prolongation, greater gestational age at delivery (36 weeks vs. 28.4 weeks, p < 0.001) and increased perinatal survival (100% vs. 42.6%, p < 0.001) compared with stage progression. Logistic regression analysis predicted that the probability of both infants surviving was 80% if the pregnancy remained at Stage I or II throughout, compared with a probability of 50% if it reached Stage III or more at 26 weeks, and only 25% if the disease reached Stage III or more at 16 weeks' gestation. CONCLUSION: Pregnancy outcome for TTTS managed with amnioreduction techniques is correlated with stage at diagnosis and the subsequent disease evolution. However, the progression of stage in TTTS is unpredictable and the likelihood of spontaneous fetal demise was not different between stages.

Cohort Studies↗
PubMed2004

Neonatal necrotizing enterocolitis following intrauterine transfusions: is there an association?

The case of a neonate with necrotizing enterocolitis (NEC) following intrauterine transfusions (IUTs) for Rhesus hemolytic disease (RHD) prompted us to undertake a retrospective study (1995-2002) to determine whether there is an association between IUT and NEC. Maternal and neonatal demographics, and details concerning IUT and definite (> or =Stage II) NEC, were collected. Chi2 tests of association were performed. In our population 281/38,200 (0.73%) pregnancies were complicated by RHD. Fetal anemia necessitated IUT in 25/281 pregnancies. Definite NEC occurred in 59/11,814 (very low birth weight=1874) neonatal admissions. Except for the index case, no other neonate developed NEC following IUT. No significant association was found between IUT and NEC.

Adult↗
PubMed2001

Fetal thyrotoxicosis after maternal thyroidectomy.

Thyroid disease commonly presents in women in their reproductive years. Maternal, fetal and neonatal outcomes are very good if the diagnosis is made early and appropriate management pathways are established. In the uncommon situation of concurrent maternal and fetal disease, the key management issues involve recognition of the involvement of the fetus and close intensive surveillance of both mother and fetus/neonate using a multi-disciplinary approach. This approach, utilising a combination of serial ultrasound of the fetus and serial biochemical testing for the mother, allows for the accurate titration of medical therapy to both patients.

Adult↗
PubMed2000

Obstetric and perinatal outcomes from the australian and new zealand twin-twin transfusion syndrome registry.

OBJECTIVE: Our purpose was to investigate the antepartum characteristics and perinatal outcomes of twin-twin transfusion syndrome cases from a multicenter national registry. STUDY DESIGN: Perinatal centers in Australia and New Zealand voluntarily notified a central evaluation registry with information on identified pregnancies with twin-twin transfusion syndrome during 1995 through 1998. RESULTS: One hundred twelve cases of twin-twin transfusion syndrome were registered. The median gestation at diagnosis was 21.5 weeks (range, 14.4-34.6 weeks). Oligohydramnios-polyhydramnios sequence was the most common presentation, with 84% of cases involving "stuck" twinning. Therapeutic amnioreduction was used in 92 cases (82.1%), with the median number of procedures per case being 2 (range, 1-23). The median gestation at delivery was 29 weeks (range, 18-38 weeks). The overall perinatal survival rate was 62.5%. Abnormal findings on cranial ultrasonography were present in 27.3% of live neonates, and periventricular leukomalacia was reported in 10.8%. Increased gestational age at delivery, the presence of umbilical artery diastolic flow, and a prolonged interval from final amnioreduction to delivery were positively associated with the delivery of live fetuses without complications. CONCLUSION: The majority of antenatally identified cases of twin-twin transfusion syndrome are managed with serial amnioreduction. Despite contemporary obstetric and neonatal management strategies, perinatal mortality and morbidity rates are high.

Australia↗
PubMed1999

Pregnancy loss rates following second trimester genetic amniocentesis.

Data from 3,953 consecutive second trimester genetic amniocenteses were analysed to determine pregnancy loss rates up to 6 weeks after the procedure. Information was prospectively collected on a cohort of 3,685 women in 3,896 singleton and 50 twin pregnancies, from 2 operating sites in Perth, Western Australia, using 9 operators over the 6-year period, 1989 to 1995. Complete information regarding pregnancy outcome was obtained for 3,643 of the 3,685 women (98.9%). There were 27 identified singletons and 1 set of twins lost within 6 weeks following amniocentesis. The overall pregnancy loss rate in this cohort was 29 of 3,911 (0.74%). The pregnancy loss rate associated with genetic amniocentesis is not excessive in comparison to the calculated background pregnancy loss rate of 1%, and it is suggested that each prenatal diagnostic team should determine their own complication rates for the purpose of counselling prior to amniocentesis.

Abortion, Spontaneous↗
PubMed1999

Prenatal diagnosis of hepatic mesenchymal hamartoma.

A case of hepatic mesenchymal hamartoma diagnosed prenatally with ultrasound and confirmed histologically post-delivery is presented. Although histologically benign, this lesion resulted in fetal demise secondary to congestive cardiac failure in the third trimester. The development of non-immune hydrops in association with a fetal hepatic mesenchymal hamartoma is a poor prognostic sign for perinatal survival.

Adult↗
PubMed1999

Prenatal sonographic appearances of Klippel-Trenaunay-Weber syndrome.

A case of prenatal Klippel Trenaunay-Weber syndrome is presented, with a description of the sonographically observed disease progression in utero. The appearance of a complex thoracic multicystic mass in association with progressive unilateral lower limb enlargement was strongly suspicious of this disorder. Colour-flow Doppler studies of the cutaneous haemangiomata in utero were not of diagnostic assistance in this case. The prenatal detection of the large cutaneous haemangiomata was of critical importance in minimizing delivery trauma for the mother and fetus.

Adult↗
PubMed1998

Ultrasound features of congenital listeriosis--a case report.

We present a case of congenital listeriosis in a twin pregnancy. Presentation was prompted by decreased fetal movements and an ultrasound examination which demonstrated features similar to those observed in an adult with inflammatory conditions of the bowel, namely, small amounts of ascites, dilated loops of bowel and thickening of the bowel wall. Such ultrasound signs may be useful in consideration of the diagnosis of congenital infection and prompt diagnostic tests and appropriate interventions that assist in early therapy.

Adult↗
PubMed1998

Fetal vascular responses to maternal glucose administration in streptozocin-induced ovine diabetes mellitus.

OBJECTIVE: To assess the impact of administration of a glucose load to the pregnant diabetic ewe on fetal biochemistry and umbilical-placental perfusion. METHODS: Six pregnant ewes were rendered glucose intolerant by the administration of streptozocin at 85-90 days gestation. An intravenous glucose load was administered to the 6 diabetic ewes and 4 control animals at 125-130 days gestation. Assessment of the fetal responses to this glucose load was made by cardiovascular monitoring, biochemical evaluation and measurement of fetal blood flows by the radioactive microsphere technique. RESULTS: In the fetus of the diabetic ewe the arterial pH progressively decreased from 7.36 +/- 0.04 to 7.10 +/- 0.09 (p < 0.05) 180 minutes after the maternal glucose load. These fetuses displayed a consistent and significant reduction in arterial oxygen tension compared to controls, with a decrease in pO2 from 14.9 +/- 3.3 mmHg at baseline to 11.3 + 3.7 mmHg after 180 minutes. Umbilical-placental blood flow did not alter significantly in the fetus of the diabetic ewe following glucose administration, although in the control fetuses there was a significant reduction from baseline after 60 minutes. Blood flow to the fetal brain and kidney were significantly elevated in the fetus of the diabetic ewe compared to control at all times, suggesting a metabolic adaptation to preserve oxygen delivery may be present. CONCLUSIONS: Maternal hyperglycemia produces profound metabolic alterations in the ovine fetus which are unaccompanied by significant alterations in umbilical-placental blood flow. In the chronically hyperglycemic pregnant ewe, a glucose load produces a major disturbance of fetal homeostasis.

Animals↗
PubMed1997

A validation study of home uterine activity monitoring technology in Western Australia.

Home uterine activity monitoring has been developed as an 'early warning' device to detect premature uterine activity, thereby encouraging earlier referral and tocolysis of women at risk of preterm delivery. This ambulatory monitoring system, utilizing a ring-guard tocodynamometer, was piloted in Western Australia to determine if it can reliably record and transmit antenatal uterine activity data in an Australian environment. Pregnant women were readily able to correctly apply and use the ambulatory monitoring device. The information collected was able to be transmitted using standard Australian telecommunications systems within our hospital environment. Validation studies with the ambulatory monitor and current external tocodynamometry hardware were performed. The ring-guard tocodynamometer detected more uterine activity at gestations less than 32 weeks compared with conventional external tocodynamometers. As term approached, however, the sensitivity of the ring-guard tocodynamometer decreased. A cross-sectional profile of antenatal uterine activity was developed for women at low risk of delivering preterm. A gradual increase in the number, duration and amplitude of uterine contractions as pregnancy advanced was observed.

Female↗
PubMed1997

Antenatal patterns of uterine activity in low-risk women: a longitudinal study.

There is a surprising lack of information on antenatal patterns of uterine activity in the normal obstetric population, with the majority of research having focussed on women at high-risk for preterm birth. We conducted a prospective longitudinal study to investigate patterns of uterine activity in women with singleton gestations at low-risk for preterm birth. Twenty pregnant women were recruited and their uterine activity was recorded using ambulatory tocodynamometry twice weekly throughout the latter half of pregnancy. The collected data were transmitted to a central receiving station for analysis. As gestation advanced there was a progressive increase in the median number of contractions detected per hour, peaking and stablizing at 37-40 weeks (median of 0 contractions/hour at 20-24 weeks rising to 5.4 contractions/hour at 37-40 weeks). In those women with uterine activity, contraction duration and amplitude of deflection significantly increased as gestation advanced. There was a progressive increase in the number of higher amplitude contractions throughout the third trimester. Increasing parity was not associated with increasing antenatal uterine contraction frequency. No association between normal daily physical activity and uterine contraction frequency was evident throughout gestation. In normal human pregnancy there is a steady, progressive increase in the frequency, duration and amplitude of antenatal uterine activity throughout the latter half of gestation. The uterine contractile profile alters from one of a low amplitude, low frequency pattern in the second trimester to a higher amplitude, higher frequency pattern at term.

Adult↗
PubMed1997

Factors influencing the selection of analgesia in spontaneously labouring nulliparous women at term.

We investigated the maternal characteristics, labour performance and delivery mode of 497 nulliparas entering labour spontaneously at term to identify the obstetric factors which influenced their choice of analgesia; 51.7% of these women used epidural analgesia. They were shorter (163 versus 165 cm, p = 0.002) and the mean gestation was 3 days greater than those not using epidural analgesia (40.2 versus 39.6 weeks, p = 0.0007). Median birth-weight in the epidural group was greater by 155 g (3,450 versus 3,295 gs, p = 0.0001). Analysis of the labour characteristics showed a lesser cervical dilatation on admission, significantly longer latent and active phases of labour and second stage length in the epidural cohort. The need for oxytocin augmentation was significantly greater in the epidural group, both prior to and after insertion. Oxytocin augmentation was strongly associated with an increased risk of operative intervention regardless of analgesia. Selection of intrapartum analgesia is not a random event and epidural analgesia appears to be an indicator of abnormal labour patterns. To further investigate the impact of analgesic methods on nulliparous labour we are currently conducting a prospective randomized controlled trial.

Adult↗
PubMed1995

Elevated mid-trimester hCG and maternal lupus anticoagulant.

An association is described between women with lupus anticoagulant and abnormal prenatal serum screening results. Three cases of positive second-trimester serum screening for Down syndrome, with karyotypically normal fetuses, in women demonstrated to have lupus anticoagulant are presented. Serum screening positivity was principally due to a disproportionately elevated maternal serum human chorionic gonadotrophin (hCG) level. In each case, early, severe intrauterine growth restriction was documented, with only one fetus surviving the neonatal period. As maternal lupus anticoagulant may have a profoundly adverse effect on the course of pregnancy, we suggest that an elevated hCG level on prenatal screening prompt consideration of maternal lupus anticoagulant testing if ultrasonography demonstrates an otherwise normal singleton gestation and the fetal karyotype is normal.

Adult↗
PubMed1995

Antenatal diagnosis and management of fetomaternal alloimmune thrombocytopenia.

Fetomaternal alloimmune thrombocytopenia (FMAT) arises from maternal-fetal platelet antigen incompatibility, which stimulates the production of maternal immunoglobulin G (IgG) platelet-specific antibody. Transplacental passage of this antibody results in fetal platelet destruction and consequent thrombocytopenia. Sequelae of thrombocytopenia may be observed in both the fetus and neonate with intracranial hemorrhage occurring in approximately 10 to 30% of affected infants. No antenatal universal screening test is currently available to detect the 50% of cases occurring in the first pregnancy. The recurrence rate in subsequent pregnancies is 75 to 85%, with a tendency to increasing disease severity. Paternal platelet genotyping is recommended to assist in risk counseling following an affected pregnancy. Prenatal therapeutic strategies are aimed at elevating the fetal platelet count in affected pregnancies and thus decreasing hemorrhagic sequelae. The most effective treatment regimen is uncertain, but encouraging results are reported with the use of maternal intravenous gamma globulin. We report our experience in the antenatal diagnosis and management of FMAT.

Adult↗
PubMed1995

Severe twin-twin transfusion syndrome: current management concepts.

The presence of functioning vascular anastomoses within the monochorionic placentation of a monozygotic twin pregnancy is responsible for the twin-twin transfusion syndrome. This is a heterogeneous disorder with a wide spectrum of severity. In the most severe form it results in the oligohydramnios-polyhydramnios sequence with a marked disparity in intertwin biometry and amniotic fluid volume. Without therapy, the perinatal mortality of severe twin-twin transfusion syndrome is 60-100%. Several therapeutic interventions have been attempted with therapeutic amniocentesis producing the most consistent improvement in fetal survival rates. The outcome of 10 cases of severe twin-twin transfusion syndrome, presenting as the oligohydramnios-polyhydramnios sequence, is presented. Gestational age at presentation ranged from 20-34 weeks. Three fetuses were hydropic at initial presentation and of these only 1 survived. All cases were treated with serial aggressive therapeutic amniocentesis, the number of procedures ranging from 1-9/patient. The volume of amniotic fluid removed ranged from 3,200-14,000 mL. Gestation was prolonged a mean of 46 days (range 1-106 days). The perinatal survival rate was 65% (13/20 infants). Preterm premature rupture of membranes and secondary preterm birth complicated 1 pregnancy treated with therapeutic amniocentesis. Short-term morbidity in the liveborn infants was predominantly secondary to prematurity and renal cortical necrosis. Severe twin-twin transfusion syndrome is the most common aetiology of the oligohydramnios-polyhydramnios sequence. Therapeutic amniocentesis offers an intervention that may reduce the high perinatal loss rate previously observed with this disorder.

Adult↗