Limitations of antenatal fetal heart rate monitors

Erroneous or doubtful decelerations in fetal heart traces were present in 111 of 1000 consecutive antenatal clinical records obtained by monitors with autocorrelation. The incidence was 20% in fetuses less than 30 weeks of gestational age. Their elimination reduced the number of "decelerative" records by 42%. Erroneous or doubtful accelerations were also present in 11% of records. These errors are caused by the fetal heart rate monitor and may contribute to the high intraobserver and interobserver variation on visual analysis. They can be detected by computer analysis.

Caesarean section dissected, 1978-1983

Of 32735 singleton births in Oxford in the 6 years 1978-1983, 10% were by caesarean section. In contrast to the national data, no trend in this rate was observed. Repeat caesarean sections accounted for 30% of all sections and the proportion of women who had had a previous caesarean section rose gradually in the hospital population. The other main indications for section were dystocia, fetal distress in labour and breech presentation, which together accounted for a further 45% of all sections. Comparison with caesarean section rates reported from North America shows that repeat sections and sections for dystocia were less frequent in Oxford but the rates for other indications were similar. Dystocia is likely to be a key factor in determining future section rates. Dystocia occurred mainly in primiparae, and was more common with short stature and with increasing gestation and maternal age. For all height, age and gestation groups dystocia was more than twice as frequent in induced as in non-induced labour. This association does not imply a causal relationship, but neither is one excluded.

Low human fetal heart rate variation in normal pregnancy

The fetal heart rates of 340 normal singleton pregnancies at 30-33 weeks gestation were screened using a microprocessor system on-line. Eleven fetuses (3.2%) with a heart rate variation less than the 5th centile were identified, of whom 10 were studied longitudinally. At 30-33 weeks the mean minute range of pulse intervals (a measure of fetal heart rate variation) was 31.4 (SE 1.5) ms compared with 51.0 (SE 3.4) ms in a randomly selected control group. The study group continued to have significantly lower fetal heart rate variation than controls on each of three subsequent occasions until delivery. There were no significant differences between the two groups in fetal outcome, which was good. This demonstrates that a small proportion of normal fetuses have consistently low heart rate variation, and helps to define the lower limit of the normal distribution of fetal heart rate variation. After delivery, there were no significant differences between heart rate or its variation between the two groups. We conclude that the lower prenatal heart rate variation in the study group was a consequence of the uterine environment.

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.

Inhibin, activin, follistatin, activin receptors and beta-glycan gene expression in the placental tissue of patients with pre-eclampsia

The objective of this study was to quantify the relative expression of inhibin alpha, inhibin/activin beta(A), beta(B), beta(C), follistatin, activin receptors and beta-glycan genes in placental tissue of term pre-eclamptic patients and controls to investigate if these genes are up-regulated in the placenta in pre-eclampsia. Seven women with pre-eclampsia symptoms were matched with 10 normal pregnant controls for gestational age, maternal age, and parity. Total RNA was isolated from each sample. Complementary DNA samples produced by reverse transcription were used in the real time PCR to quantify the expression of inhibin alpha subunit, inhibin/activin beta(A), beta(B), beta(C) subunits, follistatin, ACTRIA, ACTRIB, ACTRIIA, ACTRIIB, beta-glycan and GAPDH genes. The ratio between the target and GAPDH expression was calculated to provide relative gene expression. Inhibin alpha:GAPDH and inhibin/activin beta(A): GAPDH ratios were significantly higher in placental tissue from women with pre-eclampsia (P = 0.04 and P = 0.01 respectively) compared with matched control placental gene expression. Placental samples from both groups expressed beta(B), beta(C), follistatin, activin receptors and beta-glycan genes. However, there was no significant difference in the relative expression of these genes between the groups. Increases in the placental expression of inhibin alpha and inhibin/activin beta(A) subunit genes could contribute to the rise in circulating levels of inhibin A and activin A in pre-eclampsia. The mechanism(s) involved in increased gene expression in pre-eclampsia is as yet unclear.

Immunohistological and biochemical evidence for a role for hyaluronic acid in the growth and development of the placenta

A monoclonal antibody, designated NDOG1, has been used to stain a series of human and monkey placentae as well as several adult human tissues using immunoperoxidase techniques. In early placentae, NDOG1 was found to stain extracellular material associated with proliferating, extravillous cytotrophoblast cell columns and with the cytotrophoblast shell at the feto-maternal junction. The immunohistology suggests that NDOG1 antigen may be secreted by the anchoring cytotrophoblast into the immediately adjacent maternal tissues. NDOG1 antibody also shows extracellular staining in the stroma of early human placentae and reacted with the apical villous syncytiotrophoblast plasma membrane throughout pregnancy. Biochemical experiments demonstrated that extracts of this latter membrane contained NDOG1 antigenic activity which was susceptible to digestion with bovine testicular hyaluronidase. Hyaluronic acid was the only glycosaminoglycan found in this membrane, thereby implying a reaction between NDOG1 antibody and hyaluronic acid. Whilst no such direct interaction could be demonstrated in vitro, NDOG1 was shown to compete with two other antibodies which themselves demonstrated specificity for hyaluronic acid. The proposed identity between the NDOG1 antigen and hyaluronic acid is discussed particularly in terms of placentation where the distribution of NDOG1 staining may confirm the role of hyaluronic acid in providing an open matrix structure during stages of cell proliferation, migration and invasion.

Sera from women with unexplained infertility inhibit both mouse and human embryo growth in vitro

OBJECTIVES

To compare the effect of sera from women with reproductive disorders on the in vitro growth of mouse and human embryos up to the blastocyst stage and to determine the influence on human pregnancy outcome.

DESIGN

The growth of mouse embryos and in vitro fertilized human embryos up to the blastocyst stage was compared in sera from women with unexplained infertility, and these results were correlated with pregnancy outcome. Also the growth of mouse embryos in sera from women with a history of recurrent abortions was correlated with their pregnancy outcome. PATIENTS, SETTING: Women with unexplained infertility were attending the IVF Unit at the John Radcliffe Hospital, Oxford, United Kingdom. Women with a history of recurrent abortions were attending the high risk pregnancy unit at the same hospital.

MAIN OUTCOME MEASURES

Human embryo growth was monitored by daily morphological assessment and mouse embryo growth by both morphological assessment and tritiated thymidine uptake.

RESULTS

In 15 women with unexplained infertility, poor mouse embryo development correlated with poor human embryo quality and impaired blastocyst formation when cultured in the same serum, as well as failure to achieve a pregnancy. In 11 women with a history of recurrent abortion, inhibition of mouse embryo growth correlated with unsuccessful pregnancy outcome.

DISCUSSION

Assessment of both morphological development and cell proliferation in mouse embryos may be a useful test to determine the suitability of maternal sera for human IVF embryo culture, predicting pregnancy outcome and for categorizing women with reproductive disorders for future clinical management.

Factors associated with the blood pressures of children born to women who were hypertensive during pregnancy

At age 7.5 years the supine blood pressures of 216 children born to women who had been hypertensive during pregnancy were recorded. No associations were found between the blood pressures of the children and their mothers. The blood pressures of children whose mothers received methyldopa during pregnancy did not differ from those of children whose mothers had no specific treatment. Four boys whose mothers had taken methyldopa for more than 150 days had significantly lower systolic and diastolic pressures than those in whom the treatment had been of shorter duration. Significant findings from multiple regression analyses were: positive associations between boys' systolic and diastolic pressures and current weight, and diastolic pressure and maternal weight; negative associations between boys' systolic and diastolic pressures and birthweight; and a positive association between girls' systolic pressure and current weight.

Plasma urate and serum deoxycytidylate deaminase measurements for the early diagnosis of pre-eclampsia

The value of measuring plasma urate and serum deoxycytidylate deaminase (dCMP deaminase) for the early diagnosis of pre-eclampsia has been investigated in 45 patients. A combination of increased blood pressure and increased plasma urate identified 19 patients with a high incidence of fetal and maternal morbidity ascribable to pre-eclampsia. Seventeen of the 19 patients also had an increased serum dCMP deaminase. Serial antenatal observations for a mean period of 104 days (36-179 days) on 33 of the patients demonstrated that plasma urate and serum dCMP deaminase increased together as early changes in the development of pre-eclampsia. In six patients, blood pressure, plasma urate and serum dCMP deaminase all increased but in only one was the rise in blood pressure the first change. Elevations of plasma urate and serum dCMP deaminase are therefore both early features of pre-eclampsia. Serial measurements can give warning of the disorder before the appearance of other clinical features. The change in dCMP deaminase is probably another reflection of early renal involvement in the pre-eclamptic process.

Large fetal heart rate decelerations at term associated with changes in fetal heart rate variation

OBJECTIVE

The objective was to determine whether large antepartum decelerations in fetal heart rate were associated with a switch from high to low fetal heart rate variation, suggestive of a change in sleep state, and whether the variation predicted outcome.

STUDY DESIGN

Retrospective computerized analysis of 10,272 cardiotocographic records from 3998 patients at 37 to 42 weeks' gestation from four centers in England and Italy identified 140 good-quality records with large decelerations (more than 20 lost beats in area).

RESULTS

In otherwise normal cardiotocograms a large deceleration had a 40% chance of association with a downward change in fetal heart rate variation (69% when the deceleration exceeded 100 lost beats). The change resembled that occurring naturally with behavioral states. Uterine contractions did not always precede large decelerations. When they did, the lag time (peak of contraction-trough of deceleration) increased from 28 seconds (at 20 to 29 lost beats) to > 100 seconds with increase in deceleration area. Of patients with large decelerations 76% had a normal vaginal delivery.

CONCLUSION

Large decelerations near term, present in up to 5% of patients with otherwise normal fetal heart rate and variation, are often associated with a fall in fetal heart rate variation characteristic of a change in sleep state, without ominous significance.

Endothelial cell proliferation is suppressed by plasma but not serum from women with preeclampsia

OBJECTIVES

Evidence has been sought for a circulating factor derived from the placenta that suppresses endothelial cell proliferation and hence contributes to the maternal endothelial cell disturbances of preeclampsia.

STUDY DESIGN

The effects of sera and plasmas from women with proteinuric preeclampsia and from matched normal pregnant control women on endothelial cell proliferation were compared. The recovery of endothelial cell inhibitory activity from syncytiotrophoblast microvesicles added to male blood and prepared as plasma or serum was determined to investigate the possible placental origin of the inhibitory factor.

RESULTS

Sera from women with preeclampsia did not inhibit endothelial cell proliferation. In contrast, plasma from preeclamptic women significantly suppressed endothelial cell growth at 20% dilution compared with controls, and suppression was more pronounced in severe preeclampsia. The inhibitory activity of syncytiotrophoblast microvesicles added to blood could not be recovered from serum, only from plasma, which may explain why there was no suppression with sera from preeclamptic women.

CONCLUSIONS

These results confirm that there is a blood-borne endothelial cell suppressive factor in preeclampsia that may be derived from the placenta.

Comparison of selenium levels in pre-eclamptic and normal pregnancies

Abnormal placentation is the likely cause of the slow fetal growth and the high levels of circulating lipid peroxides found in severe pre-eclampsia. These peroxides are probably responsible for the high thromboxane:prostacyclin ratio found in this disease and may participate in the endothelial cell damage which is its most notable feature. Selenium (Se), because of its role in glutathione peroxidase, is suggested to be an important component of the removal system for these damaging peroxides. Serum-Se concentrations have therefore been measured in 19 pairs of pre-eclamptic women and matched controls. Infant birth-weights were recorded. No significant difference was found in the concentrations of Se in pre-eclamptic and control groups. Serum Se was found to be low in both groups. Birthweights were significantly lower in the pre-eclamptic group. The interpretation of serum-Se measurements from the third trimester of a pre-eclamptic pregnancy is complicated by the reduced fetal growth and probable lower Se take-up by the fetus in such a pregnancy. The merits of alternative measurements, such as total intravascular Se, placental Se, or samples from an earlier stage of gestation, are discussed. The importance of factors other than Se to the activity of glutathione peroxidase, and of other antioxidants to pre-eclamptic, is stressed.

Lymphocyte subsets in normal and pre-eclamptic pregnancies

Peripheral blood lymphocyte subsets in normal and preeclamptic pregnancies have been studied by using the monoclonal antibodies OKT3 (T cells), OKT4 (helper/inducer T cells) and OKT8 (suppressor/cytotoxic T cells). In addition the numbers of mononuclear cells bearing Ia and monocyte antigens have been assessed by using the monoclonal antibodies OKIa1 and OKM1. No significant differences were found between 10 normal pregnant and 10 non-pregnant subjects. Ten preeclamptic patients were studied and showed an increase in OKT4-positive helper cells. This was significant in terms of percentage of mononuclear cells but not the absolute numbers or the helper/suppressor (OKT4/OKT8) ratio.

Vulval intraepithelial neoplasia--management and outcome

Forty-six patients with a primary diagnosis of vulval intraepithelial neoplasia (VIN) have been managed over a 10-year period. The prevalence of VIN has increased and the age at presentation has decreased over the last decade; 59% of our patients had histological evidence of human papillomavirus infection. Pruritus was the commonest symptom at presentation (59%). Of the 46 patients 44 were treated by laser skinning vulvectomy, local excision or simple vulvectomy. Symptomatic relief was best achieved by local excision. Clinical and definitive relapse occurred more often in the laser-treated group. The median time to relapse was 38 months in the laser-treated group and 74 months in the surgically treated group (excision and simple vulvectomy). Two patients have not been treated and their disease has not progressed. The carbon dioxide laser almost certainly has a role in conservative management and although our data possibly do not reflect its full potential they demonstrate a need for a controlled prospective study.

Expression of the three endothelin genes and plasma levels of endothelin in pre-eclamptic and normal gestations

1. Maternal vasoconstriction and fetal growth retardation are part of the syndrome of pre-eclampsia and are thought to be related to placental insufficiency. There is evidence to suggest that the powerfully vasoactive endothelin peptides might be involved in the pathogenesis. 2. The production of endothelins appears to be regulated mainly by modulation of mRNA levels, and they are thought to exert their effects locally, rather than systemically. Hence, the measurement of endothelin mRNA levels in tissues would be expected to reflect the activity of the endothelin systems. 3. RNAase protection assays, using specific antisense probes capable of distinguishing between the endothelin mRNA isoforms, have been used to examine the expression of the three endothelin genes in placental villous tissue, amniotic membrane and myometrium. Samples were taken from 15 pre-eclamptic women and from 14 women with normal gestations. Myometrium was taken at hysterectomy from five non-pregnant women as an additional control. Plasma concentrations of immunoreactive endothelin [endothelin-1, endothelin-2 and big endothelin (not distinguished)] were measured in samples taken concurrently from uterine vein and peripheral blood during surgery in ten patients. 4. The level of endothelin-1 mRNA in placental villous tissue was significantly higher in pre-eclamptic women (32 weeks gestation) than in control subjects (38 weeks gestation) (1.85 +/- 0.26 versus 0.52 +/- 0.09 arbitrary units, means +/- SEM, P < 0.001) and in gravid than in non-gravid myometrium (P < 0.001). Endothelin-2 was not expressed in villous tissue, but was expressed in amniotic membrane and myometrium, with relatively little difference between pre-eclamptic and control groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Neonatal outcome after pregnancy complicated by abnormal velocity waveforms in the umbilical artery

The neonatal outcome of 61 infants born after pregnancies complicated by absent or reversed end diastolic flow velocities (AREDFV) in the fetal umbilical artery was compared with that of 61 controls matched for gestational age born after high risk pregnancies with documented forward end diastolic flow velocities (EDFV). The AREDFV group was significantly more growth retarded, had lower platelet counts at birth, and were more likely to become significantly thrombocytopenic in the first week after birth. Owing to concerns about the possible increased risk of necrotising enterocolitis in newborn infants after AREDFV, this group was started on enteral feeds later and was more likely to receive parenteral nutrition than the EDFV group. Seven infants with AREDFV and one control infant developed necrotising enterocolitis.

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.

The concentrations of the prostaglandins E and F, 13 14-dihydro-15-oxo-prostaglandin F and thromboxane B2. In tissues obtained from women with and without pre-eclampsia

The concentrations of prostaglandins E (PGE) and F (PGF), 13, 14-dihydro-15-oxo-prostaglandin F (PGFM) and thromboxane B2 (TXB2) were measured by specific radioimmunoassays in tissues obtained from women with and without pre-eclampsia. The concentrations of PGE in the amnion, chorion, decidua and placenta obtained from subjects with pre-eclampsia were significantly lower than those from subjects without pre-eclampsia. The concentration of PGE in these tissues increased significantly with gestational age and correlated with urinary oestrogen excretion. PGF concentrations were lower in the amnion and placenta of the pre-eclamptics compared to those without pre-eclampsia. The concentrations of PGFM in the amnion, decidua, and myometrium were lower in the pre-eclamptics. No significant difference in the TXB2 concentrations between the two groups of subjects were found. It is suggested that the altered tissue concentrations of prostaglandins in pre-eclamptics are due to the effects of gestational age and oestrogens and may or may not be involved in the pathogenesis of pre-eclampsia.

Prolactin in hypertensive pregnancy

Plasma prolactin levels were measured in 68 pregnant women with hypertension at 32 weeks gestation. They were raised in pregnancies with pre-eclamptic features, most significantly in women with a rising plasma urate level. No correlation was found between the level of the untreated blood pressure and prolactin. Proteinuria did not influence prolactin levels independently of changes in the plasma urate. The differences in prolactin levels could not be ascribed to the drugs administered.

Modulation of indoleamine 2,3-dioxygenase by interferon-gamma in human placental chorionic villi

The effect of interferon-gamma on indoleamine 2,3-dioxygenase, a tryptophan catabolizing enzyme, was studied in cultured human placental chorionic villi. The activity of indoleamine 2,3-dioxygenase was markedly stimulated by interferon-gamma in a time- and concentration-dependent manner. Interferon-alpha and interferon-beta also showed a slight stimulatory effect on indoleamine 2,3-dioxygenase activity. The level of indoleamine 2,3-dioxygenase mRNA expression (determined by reverse transcription-polymerase chain reaction) was also enhanced by interferon-gamma. Interleukin-4 showed a dose-dependent inhibitory effect on interferon-gamma-induced stimulation of indoleamine 2,3-dioxygenase activity and mRNA expression.