British journal of obstetrics and gynaecology最新文献

Objectives To review the experience of the University of Toronto Perinatal Complex, Ontario, Canada concerning antenatally diagnosed monoamniotic twin pregnancies; and to compare our results with cases reported in the literature with respect to antenatal surveillance and perinatal outcome.

Methods A retrospective chart review of all twin gestations from 1993 to April 2000 was performed. A systematic review of the literature, 1966 to April 2000, of perinatal outcome in monoamniotic twin pregnancies was undertaken.

Setting All monoamniotic twin gestations at the University of Toronto.

Results Case-series: 25 prenatally diagnosed monoamniotic twin pregnancies were identified. Seven pregnancies were affected by fetal anomalies. One fetus died at 29 weeks. Neonatal complications occurred below 33 weeks of gestational age and were related to immaturity. Systematic review of the literature: 49 studies met our selection criteria and reported 88 cases diagnosed antenatally. Fourteen pregnancies were affected by major congenital anomalies. Twenty fetuses died after 24 weeks of gestation. Neonatal complications varied widely in severity and depended on gestational age at birth. The risk of intrauterine fetal death was 10% at the University of Toronto and 12% in the review of the literature.

Discussion Our experience, the largest so far, suggests that regular fetal surveillance and appropriate steroid administration leads to a good perinatal outcome. The risk of fetal death (10%–12%) is lower than the previously quoted risk of 30%–70%. A careful review of obstetric interventions and further work examining outpatient surveillance of monoamniotic twin pregnancies are needed. The best treatment of monoamniotic twin pregnancies can only be determined by randomised trials.

Objective To construct gestation-specific reference intervals for fetal concentrations of biochemical markers of bone metabolism and assess the effect of rhesus isoimmunisation on these.

Methods Fetal blood samples were obtained by cordocentesis from 175 pregnancies (43 complicated by rhesus isoimmunisation) and assayed for carboxy terminal pro-peptide of type I pro-collagen (PICP) and cross-linked carboxyterminal telopeptide of type I collagen (ICTP) which directly monitor the rate of bone formation and resorption respectively.

Results Both plasma PICP and ICTP were negatively correlated with gestational age (r =−0.351 and−0.472 for PICP and ICTP, respectively, and P<0.001 for both). In fetuses affected by rhesus isoimmunisation PICP levels were lower (P=0.030) and more variable (P <0.001) than expected, compared with normal unaffected fetuses. However, no such differences were found in the ICTP levels. In the fetuses affected by rhesus isoimmunisation there was a significant correlation between haemoglobin concentration and both PICP (r = 0.504, P = 0.001) and ICTP (r = 0.343, P = 0.030).

Conclusions Fetal bone turnover declines from early second trimester to term, and may be deranged in fetuses affected by rhesus isoimmunisation.

Objective A quantitative and qualitative evaluation of the views of patients attending two types of clinics for menstrual disorders.

Methods Semi-structured qualitative interview and quantitative questionnaire.

Setting Five traditional general gynaecology clinics and a one-stop menstrual clinic, where investigations are performed and results given to patients on the same day.

Participants Two hundred and thirty-nine women (126 from the gynaecology clinic and 113 from the menstrual clinic) were recruited into the quantitative study; 18 and 26 patients from the gynaecology and the menstrual clinic, respectively, were interviewed for the qualitative study.

Main outcome measures Women's views about their care and progress towards resolution of their problem.

Results Following the initial consultation, 106 (84%) of the gynaecology clinic, and 98 (87%) of the menstrual clinic patients completed the first part of the questionnaire. Of those, 75 (71%) and 79 (81%) patients from the two types of clinic, respectively, completed a follow up questionnaire one year later. There were statistically significant differences in all the components of the first part of the questionnaire (information, continuity, waiting, organisation, and limbo) in favour of the one-stop menstrual clinic. After one year, there was a statistically significant difference in one of the components, patient centeredness, but not in overall process co-ordination. The interviews showed that patients attending the menstrual clinic appreciated getting the results of their investigations on the same day. They also found the organisation of the one-stop menstrual clinic more closely suited to their needs and as a result were more likely to feel they were making progress.

Conclusion Women were consistently more positive about their experience in the one-stop clinic. One-stop clinics organised to meet the needs of patients might be appropriate for other clinical conditions. The combination of quantitative and qualitative methods is an effective method of assessing patients’ views of health services.

Objective To compare neonatal mortality in geographical areas where most deliveries occur in large hospitals with areas where a larger proportion of deliveries occur in small maternity units.

Design Population-based study using data from The Norwegian Medical Birth Registry.

Setting Records on all deliveries in Norway from 1967 to 1996, a total of 1.7 million births, were equipped with data on the size of the maternity units used by delivering women in that particular area.

Main outcome measure Risk of neonatal death.

Results Women living in areas where the most frequently used delivery unit had less than 2000 annual deliveries had 1.2 fold the risk of experiencing neonatal death of their newborn (95% CI 1.1-1.3). The relative risk of neonatal death in geographical areas where more than 75% of deliveries occurred in units with more than 3000 annual births was 0.8 (95% CI 0.7-0.9) compared with areas where none delivered in such large units. The relative risk of neonatal death in areas where the most frequently used delivery units had less than 100 annual births was 1.4 (95% CI 1.1-1.7) compared with areas where units of more than 3000 annual births were the most frequently used. Differences in outcome could not be explained by differences in travelling distance to an urban centre where most referral delivery units are located, differences between rural and urban municipalities, or by differences in biological or socio-economic risk factors between municipalities.

Conclusions We observed a small but significantly decreased neonatal mortality in areas where the great majority of births occurred in large hospitals.

The HELLP syndrome has been associated with postpartum unconjugated hyperbilirubinaemia. Several types of disorders cause unconjugated hyperbilirubinaemia, Gilbert's syndrome being the most common. In Caucasians a genetic defect in the TATA box of the promotor region of the gene encoding for bilirubin UDP-glucuronyltransferase is tightly associated with Gilbert's syndrome. This defect was assessed by polymerase chain reaction in 237 women with the HELLP syndrome in their obstetric history and 236 controls. Fifteen percent of the cases and 10% of the controls had a homozygous genetic defect (χ² = 2.9; P = 0.23). No evidence was found that Gilbert's syndrome is associated with the HELLP syndrome.

Objectives To determine the time course of quantified volumetric flow and pulsatility index changes in the middle cerebral arteries of severe intrauterine growth restricted fetuses with absent or reversed end diastolic flow velocities (AREDFV) on umbilical artery Doppler with a view to defining the threshold for early intervention before the onset of reversal of adaptation.

Setting Fetal growth clinic of a large UK teaching hospital.

Sample Seventeen severe intrauterine growth restricted (AC<third centile for gestation and gender) fetuses with abnormal umbilical artery Doppler velocimetry and oligohydramnios (amniotic fluid index <third centile for gestation).

Methods One to three daily Doppler velocimetry and quantified volume flow of the middle cerebral artery Doppler velocimetry of the umbilical arteries and daily cardiotocography.

Results Reversal of adaptation occurred in eight fetuses, four of which ended as stillbirths and four as neonatal deaths. In two of these fetuses, this had already occurred before the diagnosis of intrauterine growth restriction. In the others, the onset was rapid and difficult to predict. Volume flow in the middle cerebral arteries decreased in those fetuses exhibiting reversal of adaptation but rose in the nine in which compensatory Doppler indices persisted. The decrease in volume flow occurred before the onset of reversal of adaptation in the pulsatility index. In the fetuses exhibiting reversal of adaptation, the rise in the pulsatility index was consistent over 48 hours compared with the physiological fluctuations in pulsatility index in some fetuses where the rise was only for 24 hours followed by a fall. Quantified volume flow fell in the fetuses before reversal of adaptation set-in. The umbilical artery Doppler indices fluctuated between absent and reversed end diastolic velocities within the same fetus irrespective of the changes in the middle cerebral artery Doppler indices.

Conclusion Reversal of adaptation is of sudden onset and is associated with poor prognosis. Predicting its occurrence on Doppler indices is difficult as the changes may be very rapid. However, volume flow changes appear to be slower and of earlier onset than the pulsatility index changes. This may therefore be a more useful tool in predicting imminent reversal of adaptation and therefore early delivery.

Objective To develop a model of the impact of population-wide periconceptional folate supplementation on neural tube defects and twin births.

Design A hypothetical cohort of 100,000 pregnancies ≥20 weeks, plus terminations of pregnancy after prenatal diagnosis before 20 weeks.

Methods Application of pooled data on the relative risks for neural tube defects and twins following periconceptional folate from meta-analysis of the randomised trials.

Main outcome measures 1. Pregnancies with a neural tube defect (i.e. terminations of pregnancy, perinatal deaths, and surviving infants); 2. twin births (i.e. preterm births, perinatal deaths, postneonatal deaths, birth defects, cerebral palsy); 3. numbers needed to treat.

Results The change in neural tube defects would be 75 fewer terminations (95% CI -47, -90), 30 fewer perinatal deaths (95% CI 18, -35), and 13 fewer surviving infants with a neural tube defect (95% CI –8, -16). The change in twinning would be an additional 572 twin confinements (95% CI –100, +1587), among whom there would be 63 very preterm twin confinements (95% CI –11, +174), 54 perinatal and postneonatal deaths (95% CI –9, +149), 48 surviving twins with a birth defect (95% CI –8, +133), and nine with cerebral palsy (95% CI –2, +26). The numbers needed to treat for the prevention of one pregnancy with a neural tube defect is 847, for the birth of one additional set of twins is 175, for the birth of one additional set of very preterm twins is 1587, and for the birth of an additional twin with any of the following outcomes (perinatal death, postneonatal death, survival with a birth defect, or survival with cerebral palsy) is 901.

Conclusions Monitoring rates of neural tube defects and twinning is essential as supplementation or fortification with folate is implemented.

Objective To investigate the effects of syncytiotrophoblast microvillous membranes (STBM) in concentrations, found in vivo in women with pre-eclampsia, on endothelial function in isolated resistance arteries.

Setting Department of Obstetrics and Gynaecology, Huddinge University Hospital, Stockholm.

Sample Twenty-nine myometrial resistance arteries isolated from biopsies of healthy term pregnant women, obtained during caesarean section.

Methods The myometrial arteries were mounted in a pressure arteriograph and perfused intraluminally for three hours with STBM (20 to 2000ng/mL) or with erythrocyte membranes or physiological salt solution as controls, all substituted with 0.5% bovine serum albumin. Bradykinin concentration-response curves were performed before and after perfusion.

Main outcome measures The bradykinin concentrationresponse curves were fitted to the Hill equation and maximal dilation and the pEC₅₀ values were determined from these fits. Differences within groups were analysed with a paired Student's t test. Electron microscopic evaluation of the endothelium was performed.

Results Neither STBM nor erythrocyte membrane perfusion affected maximal dilation or the pEC₅₀ values of the bradykinin concentration-response curves at any concentration. Examination by electron microscopy showed no obvious damage to the endothelium after perfusion with STBM or erythrocyte membranes.

Conclusion Perfusion with STBM in concentrations up to 100 times those reported in pre-eclampsia has no significant effect on bradykinin-mediated dilation in isolated myometrial arteries.