Comparative risk-benefit assessment of drugs used in the management of hypertension in pregnancy

Antihypertensive treatment in pregnancy is needed to protect the mother from the dangers of severe hypertension (greater than or equal to 170/110mm Hg), particularly cerebral haemorrhage in the context of preeclampsia. There is no evidence that treatment of the hypertension confers any other benefit; the onset and progression of preeclampsia is neither prevented nor ameliorated. Therefore, there are no indications for treating mild-to-moderate hypertension (140 to 169/90 to 109mm Hg). Intravenous hydralazine and oral nifedipine are effective drugs to treat severe hypertension acutely, the latter having the advantage of ease of administration. For long term therapy, methyldopa is the only drug which has been fully assessed and shown to be safe for the neonate and infant. beta-Adrenoceptor antagonists are safe to use in the third trimester but cause significant intrauterine growth retardation when used for longer periods. ACE inhibitors are contraindicated and diuretics should be avoided. Although calcium antagonists appear to have much potential they require further assessment of their use in pregnancy.

Prognosis for pre-eclampsia complicated by 5 g or more of proteinuria in 24 hours

Forty-two women with pregnancies complicated by pre-eclampsia and heavy proteinuria greater than or equal to 5 g/24 h were referred for conservative management to the high-risk obstetric unit in the John Radcliffe Hospital, Oxford, over a period of 5 years. Hyperuricaemia preceded the onset of heavy proteinuria in all 42 women. Most of the women had severe hypertension, but none developed eclampsia and there were no major maternal complications. Delivery was necessary within 2 weeks of onset of severe proteinuria in 88.1% of cases, although in some very preterm pregnancies delivery could be deferred for 3 or more weeks. Thirty-five women (83%) were delivered by caesarean section, 91% of whom were delivered urgently before the onset of labour. The high rate of urgent preterm operative delivery underlines the uncertainty of advanced pre-eclampsia and the need for close monitoring if delivery is to be deferred. Perinatal mortality was high; all the perinatal deaths occurred in babies of less than 29 weeks gestation. Despite heavy proteinuria, postpartum recovery was good. Three months after delivery, all but one patient had no significant proteinuria. There was no evidence of residual renal dysfunction. Although the outlook for pre-eclampsia with heavy proteinuria is limited, in a few cases pregnancy can be prolonged for significant periods of time without apparently prejudicing maternal safety and permitting enhancement of maturity at birth. The observations justify cautious conservative management even when heavy proteinuria is present.

Isolation and characterisation of a subpopulation of human chorionic cytotrophoblast using a monoclonal anti-trophoblast antibody (NDOG2) in flow cytometry

Human cytotrophoblast cells, isolated from term amniochorion by enzymic digestion and Percoll gradient centrifugation, were characterised by flow cytometry. A panel of 12 anti-trophoblast monoclonal antibodies was screened for labelling of these cells in flow cytometry and the results compared with immunoperoxidase labelling of cytospin preparations and tissue sections. All 12 antibodies were positive for trophoblast on tissue sections, 11/12 were positive on cytospins but only two (NDOG2 and GB25) gave consistent results in flow cytometry. Two-colour labelling with NDOG2 and W6/32, an antibody to HLA-A, -B, -C, demonstrated that 88% of the NDOG2-positive cells also express Class I major histocompatibility complex (MHC) antigens. The NDOG2-positive cytotrophoblast subpopulation was isolated by flow cytometry in sufficient purity (greater than 95%) and yield (3.1 x 10(6)) for use in functional studies in vitro.

Out-patient peritoneal lavage cytology in the detection of residual epithelial ovarian cancer

Peritoneal lavage fluid cytology was performed in 87 out-patients with histologically proven epithelial ovarian cancer undergoing primary management. A total of 246 peritoneal lavages were attempted, usually with temporary cannulae (n = 229). From these, 184 samples were obtained, of which 156 (85%) were suitable for cytological analysis. The sensitivity of peritoneal lavage fluid cytology in 67 patients with known residual disease was 57% whereas serum CA 125 levels were elevated in 58 (87%). Pre- and post-treatment peritoneal lavage fluid cytology had prognostic value, but this was less than that of serum CA 125 measurements.

Congenital heart block with hydrops fetalis treated with high-dose dexamethasone; a case report

A 32-year-old woman with systemic lupus erythematosus was found to have a fetus with heart block and fetal ascites at 23 weeks gestation. Treatment with high-dose corticosteroids ameliorated the early signs of heart failure, although the fetal heart rate gradually fell from 48 beats/min to 42 beats/min by 34 weeks. Sudden deterioration of the fetal state occurred at 35 weeks, and this only partially responded to digitalisation. Neonatal death occurred on Day 18 from the consequences of severe birth asphyxia. The relationship and pathogenesis of anti-Ro antibodies, congenital heart block and hydrops fetals are discussed, together with the in utero management of this condition.

Syncytiotrophoblast membrane protein glycosylation patterns in normal human pregnancy and changes with gestational age and parturition

The fetally derived syncytiotrophoblast in the placenta form the major interface with the maternal circulation. Cell surface N-linked oligosaccharides are known to influence cell-cell interactions in a variety of ways. The N-linked oligosaccharide component of the human syncytiotrophoblast membrane has been purified from term placentae, and its biochemical structure analysed. Ninety-five per cent of structures were complex N-linked oligosaccharides, with the remaining 5 per cent being of the oligomannose type. Seventy-two per cent of oligosaccharides were sialylated; 50 per cent having two or more sialic acid residues. Such a population of N-linked oligosaccharides would be expected to provide a surface which inhibits interactions between trophoblast and maternal leukocytes. The temporal changes in syncytiotrophoblast N-linked oligosaccharides from the end of the second, and through the third trimester (25-41 weeks) were analysed, as were the changes which occur during parturition. There was no change in the degree of sialylation of these structures. The only significant change was a 37 per cent decrease in core fucosylation of complex N-linked sugars during gestation (P less than 0.005). Women delivered by caesarean section at term, had significantly higher levels of fucosylation (equivalent to women with a gestational age of 31-36 weeks), than those who laboured at term. Present knowledge of core fucosylation of N-linked oligosaccharides is discussed in relation to trophoblast functioning.

Computerized fetal heart rate analysis in labor

Observer variation in visual analysis of fetal heart rate (FHR) records is reportedly high, but can be avoided by computerized numerical analysis. The FHRs of 394 women in labor at 37 or more weeks' gestation were recorded on-line and analyzed to examine how different patterns related to outcome, as judged by umbilical arterial base deficit or Apgar score on delivery. The range of normality and the diversity of patterns of those delivered without acidemia were great. Late decelerations were of poor prognostic value. There was an increase in FHR variation during labor averaging 40%. In this preliminary study, conventional attributes of the FHR, alone or in combination, did not predict metabolic acidemia. Epidural analgesia in 240 women was identified as a confounding variable that significantly affected FHR patterns without influencing the condition of the infant at birth. It was associated with a higher FHR, less FHR variation and fewer decelerations, primiparity, longer labors, more operative deliveries, and a threefold greater cesarean rate. The rise in basal FHR, perhaps due to a rise in maternal temperature, may partly explain the high intervention rate in those without fetal acidemia.

The effect of maternal anaemia and iron deficiency on the ratio of fetal weight to placental weight

OBJECTIVE

To examine the maternal influences which determine large placental weight and a high ratio of placental weight to birthweight. These are known predictors of adult blood pressure.

DESIGN

Retrospective analysis of routine obstetric and haematology department records for a large cohort of pregnant women.

SETTING

John Radcliffe Hospital, Oxford.

SUBJECTS

8684 pregnant women who were delivered between January 1987 and January 1989 and whose records could be linked to the results of two or more pregnancy blood counts.

MAIN OUTCOME MEASURES

Placental weight and the ratio of placental weight to birthweight.

RESULTS

Large placental weight was associated with a low maternal haemoglobin and a fall in maternal mean cell volume during pregnancy. The highest ratio of placental weight to birthweight occurred in the most anaemic women with the largest falls in mean cell volume. Large placental weight and a high ratio of placental weight to birthweight were also independently associated with a high maternal body mass index. Maternal smoking reduced placental weight, but increased the ratio of placental weight to birthweight.

CONCLUSIONS

Anaemia and iron deficiency during pregnancy are associated with large placental weight and a high ratio of placental weight to birthweight. This points to maternal nutritional deficiency as a cause for discordance between placental and fetal growth. This may have important implications for the prevention of adult hypertension, which appears to have its origin in fetal life.

Short-term variation in abnormal antenatal fetal heart rate records

In a retrospective study the relation of reduced fetal heart rate variation to fetal acidemia was analyzed with a computerized system for numeric analysis. Between 1983 and 1987, 78 pregnancies were identified in which at least one record of the fetal heart rate had very low long-term variation. The outcome was analyzed to determine the numeric criteria of fetal heart rate variation that most efficiently detect a fetus that will die (preterminal) or is dying (terminal). Because fetal compromise was found on occasion to be associated with a slow sinusoidal fetal heart rate rhythm that increased measures of long-term variation. It was necessary to define a new index of short-term fetal heart rate variation (the 1/16 minute epoch-epoch variation). This was closely related to long-term variation (r = 0.9) but provided better detection of preterminal records as judged by metabolic acidemia at delivery or intrauterine death.

Umbilical artery resistance index as a screening test for fetal well-being. II: Randomized feasibility study

To determine whether the time taken for fetal assessment could safely be reduced by preliminary screening with Doppler ultrasound, 897 women having fetal assessment in the high-risk unit of the John Radcliffe Hospital, Oxford, were randomly allocated to two groups. In the Doppler group, preliminary assessment was by umbilical artery resistance estimation, and in the fetal heart rate (FHR) group by computerized FHR analysis. To minimize the risk of failing to recognize fetal distress, the criteria for using the nonallocated method as well were deliberately conservative. Thus, 66% of the 1869 Doppler studies done in the Doppler group and 39% of the 2069 FHR tests done in the FHR group needed to be followed by the nonallocated tests. Trained nursing staff performed the Doppler studies as part of their routine duties. Doppler studies were unsuccessful in obtaining a result on 26% of the occasions. Under the above clinical circumstances, preliminary Doppler screening did not reduce the time taken for fetal assessment. There were no significant differences in perinatal outcome between the groups, except that emergency as opposed to elective cesareans were less frequent in the Doppler group. As this finding was not predicted by previous hypothesis, it needs to be confirmed.

Computerized analysis of episodic changes in fetal heart rate variation in early labor

Fetal heart rate variation in early labor was measured by computerized analysis in cyclic episodes of low or high variation in 136 women at 37 to 42 weeks' gestation. The amplitude (mean +/- SE) in episodes of low variation was 20.6 +/- 0.4 milliseconds; in high variation it was 57.3 +/- 1.1 milliseconds. The duration (mean +/- SE) of low episodes (24.3 +/- 1.3 minutes) was less than that of high episodes (45.1 +/- 2.7 minutes) but was sometimes greater than 1 hour. In episodes of low variation the amplitude was less than 5 beats/min long term in 11% and less than 2.5 milliseconds (pulse intervals) short term in 8%; these measures would be predictive of intrauterine death if persistent before birth. We conclude that the use of decreased fetal heart rate variation as a diagnostic sign of acute fetal hypoxemia in labor is incorrect, because changes of this size occur randomly as a consequence of fetal sleep states. There was no significant correlation between fetal heart rate variation over the last hour of labor and umbilical arterial base deficit on delivery.

Qualitative and quantitative analysis of peritoneal fluids from women with gynecologic diseases. Comparison of cytology and flow cytometry for the detection of malignancy in lavage and ascitic fluids

A prospective study was undertaken to compare flow cytometric (FCM) analysis to conventional cytologic evaluation for the detection of malignant cells in peritoneal fluids (peritoneal lavages and ascitic fluids) from women with gynecologic diseases. The 94 peritoneal fluids analyzed came from 63 cancer patients (with epithelial ovarian carcinomas) and 31 control patients (with benign gynecologic diseases). The FCM DNA histograms were generated using propidium iodide as a DNA fluorochrome. Samples for cytologic analysis were stained with the standard May-Grünwald-Giemsa or Papanicolaou stains. Of the 94 samples, 90 were evaluable cytologically while 70 were suitable for FCM analysis. The sensitivities were 55% for FCM DNA analysis and 80% for cytologic analysis. FCM DNA analysis had a 30% false-positive rate; cytologic analysis produced no false-positive results. These results indicate that there is no advantage in employing FCM analysis instead of conventional cytologic evaluation for the detection of malignant cells in peritoneal fluids from gynecologic cases.

Controlled trials of antihypertensive drugs in pregnancy

It is taken for granted that severe hypertension in pregnancy should be treated, although the principle has not been formally tested by properly controlled trials. There is less certainty about treating mild to moderate hypertension (140/90 to 169/109 mm Hg). The risk of chronic hypertension in pregnancy depends on that of superimposed preeclampsia, which must be prevented by control of the blood pressure if antihypertensive treatment is to be beneficial. There is not a priori reason why lowering the blood pressure should have this effect. Most of the trials of treatment have been too small to provide conclusive answers. Usually treatment has been started too late to give a realistic expectation of influencing the evolution of superimposed preeclampsia. However, the largest trial of the early use of methyldopa in women with mild chronic hypertension, showed clearly that treatment does not prevent the superimposition of preeclampsia. beta-Adrenergic blocking agents, if used from the second start of the trimester, are associated with a major risk of severe growth retardation and are therefore contraindicated. Methyldopa has the best safety record, which includes long-term follow-up to assess the development of children exposed to methyldopa in utero. The ineffectiveness of antihypertensive drugs in preventing or ameliorating preeclampsia needs to be contrasted with the consistent evidence for the effectiveness of antiplatelet therapy. This is consistent with the increasing evidence that preeclampsia is not primarily, or even necessarily, a hypertensive disease.

Detection of fetal cells in maternal blood

We report the detection of fetal cells in the maternal circulation by enzymatic amplification of a single copy gene sequence that was fetal-specific. Fetal HLA-A2-positive cells were sorted from maternal HLA-A2-negative cells by flow cytometry and confirmed by demonstration of a fetal-specific HLA-DR4 sequence. However, this sequence could not be detected in unenriched maternal DNA prepared at 28 and 32 weeks' gestation. The sensitivity of detection was 1 HLA-DR4-positive cell in 10(5) HLA-DR4-negative cells. We conclude that prenatal diagnosis of paternally inherited autosomal-dominant genetic defects may be possible by selective gene amplification of maternal peripheral blood. However, preliminary enrichment for fetal cells may be necessary.