Effect of maternal betamethasone on fetal and uteroplacental blood flow velocity waveforms.

OBJECTIVES: To investigate the effects of antenatal betamethasone on fetal and uteroplacental hemodynamics. METHODS: The study comprised 33 women with singleton high-risk pregnancies (23-33 weeks; 27 pregnancies < 30 weeks) not in labor, but at risk for preterm delivery based on fetal or maternal indications. They were treated with two doses of 12 mg betamethasone intramuscularly 24 h apart to enhance fetal lung maturity. Flow velocity waveforms were recorded with Doppler ultrasound from the umbilical artery, the fetal middle cerebral artery, the ductus venosus and both maternal uterine arteries, once before and twice after betamethasone administration. RESULTS: Twenty-one (64%) women delivered within 4 days, nine (27%) women within 5-7 days and three (9%) within 8-15 days after the first dose of betamethasone. Two days after betamethasone, a decrease in pulsatility index was found in the umbilical artery (P = 0.0002) and ductus venosus (P = 0.003). Changes in the umbilical artery waveform from reversed to absent, and from absent to positive diastolic flow, were noted in 12 of 15 cases (P < 0.01). After 4 days, umbilical artery and ductus venosus velocity waveforms in the undelivered fetuses either returned to the type of waveform observed before treatment or showed further deterioration. No significant effects of betamethasone were observed in the fetal middle cerebral artery and uteroplacental circulation. CONCLUSIONS: Maternal antenatal betamethasone resulted in a significant transient change in the velocity waveform and a decrease in the pulsatility index in the umbilical artery and ductus venosus, but did not influence uteroplacental circulation. These findings indicate a direct effect of betamethasone on fetal circulation.

Early intervention in management of very preterm growth-restricted fetuses: 2-year outcome of infants delivered on fetal indication before 30 gestational weeks.

OBJECTIVES: To describe the outcome of growth-restricted fetuses with absent or reversed end-diastolic flow (ARED) in the umbilical artery delivered on fetal indication before 30 gestational weeks. METHODS: Between 1998 and 2004, 42 fetuses with intrauterine growth restriction (IUGR) and ARED in the umbilical artery were delivered liveborn by Cesarean section on fetal indication before 30 gestational weeks. The median gestational age at delivery was 27 + 1 (range, 24 + 4 to 29 + 5) weeks. An additional four fetuses died in utero at a median gestational age of 24 + 2 (range, 23 + 5 to 25 + 4) weeks. Neonatal morbidity, infant mortality and major neurological morbidity of liveborn infants were compared with those in two control groups: all 371 liveborn infants delivered at < 30 weeks during the corresponding time period (Group A) and a subset of these, 42 matched infants without IUGR (Group B). RESULTS: Thirty-two fetuses (76%) [corrected] were delivered within 48 h of the occurrence of ARED (25 absent, seven reversed end-diastolic flow). The remaining 10 fetuses (five absent, five reversed end-diastolic flow) were monitored for a median of 6.5 (range, 3-18) days before delivery. One infant died in the neonatal period and three during the first year of postnatal life (2-year survival 90%). The incidence of chronic lung disease was higher in the ARED Group than in Control Groups A and B (P = 0.001 and P = 0.03, respectively). There were no differences between the groups in the occurrence of necrotizing enterocolitis, cerebral hemorrhage or retinopathy of prematurity. Cerebral palsy was diagnosed in 14% of the index group compared with 11% and 17% of Control Groups A and B (P > 0.05). CONCLUSIONS: Very preterm growth-restricted fetuses with umbilical artery ARED delivered on fetal indication, in most cases before the occurrence of severe changes in the ductus venosus velocity waveforms and/or fetal heart rate tracings, showed high 2-year survival and low morbidity.

Intrauterine asphyxia and long-term outcome in preterm fetuses.

The long-term outcome of 108 infants born before the 33rd week of gestation was evaluated and correlated to a fetal heart tracing from the last 24 hours before delivery. Infants with signs of asphyxia (N = 30) were born at the same gestational age as those without (N = 78), but had a significantly lower birth weight (P less than .001). Severe intraventricular hemorrhage occurred more often in infants with asphyxia (30%) than in those without (5%) (P less than .05). Fourteen of 30 asphyxia infants (47%) and 11 of 78 nonasphyxia infants (14%) died within the first two years (P less than .005). At two years of age, four (25%) asphyxia and eight (12%) nonasphyxia infants have developmental or neurologic abnormalities (not significant). Of the eight infants with asphyxia born before the 29th week of gestation in the present study, none was normal at two years of age. The authors conclude that signs of asphyxia, as determined from fetal heart rate pattern, were associated with poor fetal outcome, and especially in infants born before the 29th week of gestation. The clinical implications of these findings are discussed.

Umbilical artery Doppler velocimetry as a labor admission test.

Doppler ultrasound of the umbilical artery flow velocity waveform was studied prospectively as an admission test at the labor ward. Recordings were made in 575 women in various stages of labor before, during, and after uterine contractions, and evaluated in relation to intrapartum and fetal outcome variables. No association was found between abnormal flow velocity waveforms and cord complications, meconium-stained amniotic fluid, or abnormal fetal heart rate tracing, nor was there any association with operative delivery for fetal distress or low Apgar scores at 1 and 5 minutes. Small for gestational age fetuses had significantly more abnormal flow velocity waveforms than appropriate for gestational age fetuses, and so had those with umbilical artery acidemia compared with those with normal pH. The results indicate that Doppler recording of the umbilical artery flow velocity waveform as an admission test at the labor ward is not a good predictor of fetal distress in an unselected population.

Waveform pattern recognition--a new semiquantitative method for analysis of fetal aortic and umbilical artery blood flow velocity recorded by Doppler ultrasound.

A semiquantitative computerized waveform pattern recognition system for analysis of the fetal descending aortic and umbilical artery Doppler flow velocity waveforms is presented. Based on empirically and manually selected clinical recordings from both vessels, 11 computerized and normalized standard curves for the aorta (type curves A to K), and 10 curves for the umbilical artery (type curves a to j) were constructed. The best match between the normalized waveform and the standard curve was based on either the degree of absent diastolic flow or, in cases with positive diastolic flow, on the calculation of the least square sum of the difference. The pattern recognition was tested against conventional waveform indices and our older semiquantitative Blood Flow Class (BFC) system in 472 clinical consecutive Doppler recordings. A good correlation was found. This new relatively simple computer-based method for waveform analysis is now prospectively applied in clinical studies.

Lactate and acid-base balance at delivery in relation to cardiotocography and T/QRS ratios in the second stage of labour.

OBJECTIVE: To compare foetal electrocardiogram (T/QRS ratio) and cardiotocography (CTG) during the second stage of labour with lactate and acid-base balance in cord artery blood at delivery. DESIGN: Forty-six parturients delivered at the National University of Singapore were monitored during the second stage of labour with T/QRS ratios and CTG. At delivery blood from a segment of clamped cord was sampled for lactate and acid-base balance analyses. The Spearman Rank correlation, the Mann Whitney U-test and the Kruskal Wallis ANOVA were used when appropriate. RESULTS: Maternal pushing time was significantly correlated to lactate (R = 0.51; P = 0.0003), pH (R = -0.38; P = 0.009) and base deficit (R = 0.33; P = 0.026), but not to T/QRS ratio (R = 0.002; P = 0.99). No significant correlation between lactate and T/QRS ratios (R = 0.06; P = 0.70) or type of CTG pattern was found (P = 0.10), though there were significant differences in pH (P = 0.029) and T/QRS ratios (P = 0.037) between groups with different FHR abnormalities. CONCLUSION: Lactate increases progressively with maternal pushing time. No significant correlation was found between lactate and the T/QRS ratio. Lack of correlation is likely to be due to poor sensitivity of foetal ECG at this level of foetal stress, though the influence from transplacentally transferred maternal lactate cannot be excluded.

Correlation between range of motion and implant fracture: a 5 year follow-up of 72 joints in 18 patients in a randomized study comparing Swanson and Avanta/Sutter MCP silicone prosthesis.

Eighteen out of 18 rheumatoid patients (at one centre of a two-centre 30 patient study previously reported) with a mean age of 56 years, and 72/72 operated joints were randomized to Avanta/Sutter or Swanson MCP prostheses and followed for 5 years. Both ulnar deviation and extension lag were improved already at 6 weeks and remained improved at 5 years. The Avanta prosthesis had a better range of motion (ROM) than the Swanson. Six of nine patients with Avanta/Sutter implants had at least one implant fracture compared to 1/9 patients with the Swanson implant (P = 0.05) but fracture did not change the outcome subjectively. The ROM at 3 months correlated with the occurrence of an implant fracture at 5 years and a greater early ROM may be related to implant fracture. At 5 years patients remained satisfied and the deformities remained corrected.

Screening for Down syndrome based on maternal age or fetal nuchal translucency: a randomized controlled trial in 39,572 pregnancies.

OBJECTIVES: Nuchal translucency (NT) screening increases antenatal detection of Down syndrome (DS) compared to maternal age-based screening. We wanted to determine if a change in policy for prenatal diagnosis would result in fewer babies born with DS. METHODS: A total of 39,572 pregnant women were randomized to a scan at 12-14 gestational weeks including NT screening for DS (12-week group) or to a scan at 15-20 weeks with screening for DS based on maternal age (18-week group). Fetal karyotyping was offered if risk according to NT was > or = 1:250 in the 12-week group and if maternal age was > or = 35 years in the 18-week group. Both policies included the offer of karyotyping in cases of fetal anomaly detected at any scan during pregnancy or when there was a history of fetal chromosomal anomaly. The number of babies born with DS and the number of invasive tests for fetal karyotyping were compared. RESULTS: Ten babies with DS were born alive with the 12-week policy vs. 16 with the 18-week policy (P = 0.25). More fetuses with DS were spontaneously lost or terminated in the 12-week group (45/19,796) than in the 18-week group (27/19 776; P = 0.04). All women except one with an antenatal diagnosis of DS at < 22 weeks terminated the pregnancy. For each case of DS detected at < 22 weeks in a living fetus there were 16 invasive tests in the 12-week group vs. 89 in the 18-week group. NT screening detected 71% of cases of DS for a 3.5% test-positive rate whereas maternal age had the potential of detecting 58% for a test-positive rate of 18%. CONCLUSIONS: The number of newborns with DS differed less than expected between pregnancies that had been screened at 12-14 weeks' gestation by NT compared with those screened at 15-20 weeks by maternal age. One explanation could be that NT screening--because it is performed early in pregnancy--results in the detection and termination of many pregnancies with a fetus with DS that would have resulted in miscarriage without intervention, and also by many cases of DS being detected because of a fetal anomaly seen on an 18-week scan. The major advantage of the 12-week scan policy is that many fewer invasive tests for fetal karyotyping are needed per antenatally detected case of DS.

Reactivity of non-stress tests and its relationship to outcome in infants born prior to the 33rd week of gestation.

In order to evaluate the significance of the non-stress test (NST) in the immature fetus, 60 patients who gave birth between the 26th and 33rd week of gestation were studied. They were grouped according to reactivity of the last non-stress test performed 24 hours prior to delivery. Twenty-eight (47%) of the patients were reactive, 10 (17%) non-reactive, and 22 (37%) non-reactive with decelerations on the last NST. The one-year mortality rates were significantly higher in those non-reactive with decelerations (41%) and in those non-reactive (30%), than in the reactive group (7%) (p less than 0.001, p less than 0.05). The results suggest that reactive non-stress tests and those that are non-reactive with decelerations predicted the fetal outcome similarly to the same findings in term pregnancies. Non-reactive non-stress tests without decelerations were associated with poor outcome in fetuses with a gestational age of more than 29 weeks. Conversely, in more immature fetuses, nonreactive patterns occurred in patients with favorable outcome. The clinical implications of these findings are discussed.

Doppler blood flow changes and placental morphology in pregnancies with third trimester hemorrhage.

Combined real-time ultrasound and pulsed Doppler ultrasound examinations were performed in 67 patients with third trimester hemorrhage and other symptoms related to placental abruption, starting from the onset of symptoms to delivery. In 52 of the cases, placental morphology was investigated by light microscopy. Thirteen patients were ultimately given the diagnosis abruptio placentae. None of the morphological placental changes considered had any statistical relationship to placental abruption. Patients with placental centrocotyledon hemorrhages and infarction more often had abnormal umbilical artery flow velocity waveforms at the onset of symptoms, and more frequent abnormal arcuate artery flow velocity waveforms were found among those with placental infarction alone. Abnormal flow velocity waveforms in the umbilical and arcuate arteries were associated with placental abruption, both at the onset of symptoms and at the final examination before delivery. The results indicate an increased risk for placental abruption if the arcuate and/or umbilical artery flow velocity waveforms are abnormal in patients with third trimester hemorrhage.

Umbilical artery velocimetry and non-stress test in monitoring high-risk pregnancies. A comparative longitudinal study.

In a longitudinal comparative study, umbilical artery velocimetry and the non-stress test were used in parallel for surveillance of 153 hospitalized high-risk pregnancies. The occurrence of abnormal flow velocity waveforms of the umbilical artery, with increased pulsatility index but maintained diastolic flow velocity, was an inconsistent finding and often related to pregnancy complications other than intrauterine growth retardation. Among patients with small-for-gestational age fetuses or pre-eclampsia with a small-for-gestational age fetus, there was a significantly higher frequency of abnormal umbilical flow velocity waveforms. This was a consistent finding and was often associated with an absence of diastolic flow velocity and operative delivery for fetal distress. An abnormal non-stress test had a significant relationship with intrauterine growth retardation, but a lower predictive capacity for this condition than the abnormal umbilical artery flow velocity waveform. In patients with small-for-gestational age fetuses and no other complication of pregnancy, umbilical artery velocimetry can be used as a reliable tool for identifying those fetuses that need intensified surveillance. In cases with additional complications, a combined use of blood velocimetry and the non-stress test is advocated.

Fetal and uteroplacental blood flow in prolonged pregnancies. A clinical study.

In a prospective study during 1 year, 102 women with prolonged pregnancies (more than 294 completed gestational days) were followed with serial pulsed Doppler blood flow examinations every 2nd day, either to spontaneous onset of labor (n = 82) or to induction of labor due to subsequently occurring complications (n = 20). Mean aortic blood velocity did not change significantly with gestational age beyond 294 days either in fetuses with normal outcome or in fetuses that developed asphyxia at birth. The flow velocity waveforms in the descending aorta, the umbilical artery, the common carotid artery and the uterine artery did not change significantly compared to the values at term. Abnormal flow velocity waveforms in the fetal descending aorta, umbilical artery or uterine artery had no significant relationship to fetal asphyxia. Absence of diastolic flow velocities was not found in any of the vessels examined, indicating that the fetuses did not suffer from chronic hypoxia in utero and that aging of the placenta did not alter fetal and uteroplacental blood flow. Notching of the aortic flow velocity waveform was a common finding among prolonged pregnancies. The hemodynamic implications and consequences of this phenomenon are discussed.

Fetal breathing recorded by actocardiogram and real--time ultrasonography. A comparison.

BACKGROUND: The aim of the study is to evaluate the ability of fetal actocardiogram to assess fetal breathing movements. METHODS: A descriptive study. Evaluation of the agreement between real-time ultrasound and actocardiographic assessment of fetal breathing movements. Eleven unselected pregnancies admitted because of various pregnancy complications. RESULTS: In six cases the breathing pattern recorded by the actocardiogram correlated to the findings with real-time ultrasonography. In five cases where fetal breathing was observed on the ultrasound screen, the actocardiogram did not either indicate breathing or was of an indecisive appearance. Two cases where no breathing was observed on real-time ultrasound yielded actocardiograms without patterns typical of breathing, but with activity difficult to distinguish from breathing. CONCLUSIONS: With the paper speed set at 3 cm/min it is possible to detect some types of fetal breathing or the absence of breathing with accuracy on the actocardiogram. However, in cases without deep and regular diaphragmatic excursions it is not possible to evaluate breathing with certainty by the actocardiogram.

Diameters of the common carotid artery and aorta change in different directions during acute asphyxia in the fetal lamb.

The aim of this experimental ultrasound study on six fetal lambs was to evaluate how blood flow variables and vessel diameters of the descending aorta and the common carotid artery change during fetal asphyxia in the acute preparation. When acute asphyxia was induced by obstructing the maternal aortic blood flow all fetuses reacted with significant decrease in the aortic diameter and blood flow. In the common carotid artery vessel diameter and the blood flow increased significantly. The results support the theory of a brain sparing effect during fetal distress with significant changes of blood vessel diameters occurring in opposite directions in the aorta and the common carotid artery, thereby contributing to the centralisation of circulation.

Assessment of fetal health should be based on maternal perception of clusters rather than episodes of fetal movements.

OBJECTIVE: To determine the level of correlation between mother and machine detected episodes and clusters of fetal movements and their association with fetal heart rate acceleration. METHODOLOGY: An observational study conducted on health pregnant women between 29-40 weeks gestation who were admitted in spurious labour to the Department of Obstetrics and Gynaecology, National University Hospital, Republic of Singapore. A continuous record of fetal heart rate and fetal movement was obtained using the fetal actocardiograph. Fetal movements felt by mother were also noted. If a continuous series of fetal movements were perceived over a period of 15 secs or more it was termed clusters of fetal movement. The presence or absence of acceleration in relation to these movements were noted. RESULTS: There was a highly significant correlation between mother and machine in detection of clusters of fetal movements (r = 0.77, p < 0.001); for episodes of fetal movements, the correlation was weaker (r = 0.23, p < 0.05). All clusters of fetal movements perceived by the mother were recorded by the machine and were associated with fetal heart rate accelerations. Two or more accelerations within 3 minutes of the fetal movements were seen with 87.8% of clusters felt by mother compared with 66.7% detected by the machine (p = 0.01). In the 2,263 minutes of recording in 42 women, a cluster of fetal movements was felt at least every 25 minutes by the mother. CONCLUSION: Maternal perception of 1 or 2 clusters of fetal movements in 30 to 60 minutes may be as reliable as a non-stress test in reassuring good health. It would be less time consuming than the traditional count to 10 fetal movement chart and a more reliable indicator of fetal health than counting episodes of fetal movements. Thus, our study suggests that clusters rather than episodes of fetal movements should be considered for evaluating fetal health based on fetal movements.

Preeclampsia: haemostatic status and the short-term effects of methyldopa and isradipine therapy.

OBJECTIVE: To determine the haemostatic status in preeclampsia and to investigate the effects of short-term use of anti-hypertensive drugs, methyldopa and isradipine. METHODS: Thirty preeclamptic (PE) women admitted to the hospital for observation and treatment were randomized to receive either methyldopa or isradipine for 2 weeks. Their blood pressure were monitored for 24 h before treatment and again at 7 days and 14 days after treatment using the programmable automated ambulatory blood pressure (ABP) monitoring system. Blood sampling was performed before commencement of anti-hypertensive treatment, 7 days and 14 days after treatment and the haemostatic parameters studied was compared before treatment with normal pregnancy and the effect of anti-hypertensive treatment. Nineteen normal pregnant subjects with a total of 30 blood sampling at various gestation and good pregnancy outcome served as controls. The following haemostatic parameters were determined; thrombelastography, fibrinogen, antithrombin III (ATIII), thrombin-antithrombin (TAT)-complex, beta-thromboglobulin (beta-TG), plasminogen activators (t-PA, u-PA), plasminogen activator inhibitors (PAI-1, PAI-2), and plasminogen. RESULTS: Significant lowering of blood pressure was evident at Days 7 and 14 of therapy with either methyldopa or isradipine. Increased mean plasma fibrinogen and decreased ATIII levels were seen in preeclampsia together with decreased u-PA and t-PA activity levels in contrast to increased t-PA antigen and beta-TG. No significant differences were seen for TAT-complex, PAI-1, plasminogen and D-dimer levels although their mean levels were higher than observed in non-pregnant subject except for PAI-2, the level was significantly reduced when compared with normal pregnancy. Two-way analysis of variance showed no significant alteration on all haemostatic parameters studied in preeclamptic women receiving either methyldopa or isradipine after 7 and 14 days of therapy. CONCLUSION: Enhance activation of coagulation was observed together with raised fibrinolysis in normal pregnancy and PE. However, in PE a further reduction in ATIII, u-PA and PAI-2 with increased fibrinogen and platelet activation could lead to an imbalance in the coagulation/fibrinolysis equilibrium which favours fibrin deposition. All these changes seen in PE including the coagulation kinetics were not altered by the short term effects of methyldopa and isradipine even though significantly lowered blood pressure were observed during therapy.