Intrauterine pressure studies in multigravid patients in spontaneous labour: effect of oxytocin augmentation in delayed first stage.

Uterine activity was assessed by measuring the uterine activity integral (UAI) in 116 black multigravid patients in spontaneous active labour at term. Although individual patients showed a wide range of mean UAI levels, normal labour (group I, n = 54) was associated with a mean UAI level of 1640 kPas/15 min which was higher than the mean level observed in patients in whom delay in cervical dilatation occurred in active labour. The patients who failed to progress in labour were treated with oxytocin infusion and 32 of them made good progress in labour and achieved vaginal delivery (group IIa: mean UAI pre-oxytocin treatment 1040 (SD 424) kPas/15 min, post-oxytocin 1890 (SD 559) kPas/15 min). The other 23 patients required operative delivery (group IIb) despite correction of uterine activity after oxytocin treatment (pre-oxytocin mean UAI 1230 (SD 570) kPas/15 min, post-oxytocin 1815 (SD 650) kPas/15 min). The rate of oxytocin infusion varied between patients from 2 to 16 mU/min but in 75% uterine activity was corrected to normal levels by a dose of less than or equal to 8 mU/min. It is concluded that delay in progress in labour is associated with lower intrauterine pressures than are present in normal labour, and that management of patients presenting with inefficient uterine action may benefit from the use of uterine activity integral measurements.

Comparison of labetalol and dihydralazine in hypertensive emergencies of pregnancy.

Labetalol (Trandate; Allen & Hanburys), a combined alpha- and beta-adrenergic blocking agent, was compared with the more commonly used peripheral vasodilator, dihydrallazine (Nepresol; Ciba), each administered as an infusion, in the treatment of severe hypertension in 20 primigravidas at greater than or equal to 32 weeks' gestation. With the dosage regimen used in this study there was a tendency towards more effective blood pressure control with dihydrallazine. The pulse rate was unaffected by labetalol therapy and there were no harmful effects on the neonate or fetus directly attributable to either drug.

Changes in amniotic fluid prostaglandins with oxytocin-induced labor.

Amniotic fluid prostaglandin levels were measured serially in 15 patients who underwent successful induction of labor and compared with those of patients presenting in spontaneous labor. At comparable cervical dilation the induced group demonstrated significantly lower prostaglandin levels. Four of these patients delivered without any increment in prostaglandins while in the remaining patients increases in prostaglandins followed the attainment of efficient uterine contractions by several hours. These data support the hypothesis that oxytocin acts directly on myometrial cells and not primarily by prior generation of prostaglandin synthesis in the membranes.

Rupture of the gravid uterus.

A detailed analysis of 129 cases of rupture of the gravid uterus between 1980 and 1983 is presented and compared with two previous reports from King Edward VIII Hospital, Durban, over the last 2 decades. Statistically significant decrease in the occurrence of this condition (from 2,7 to 1,06/1000 deliveries (P less than 0,001; chi 2 = 20,38)) and in the maternal mortality rate (from 12% to 3%) have taken place since the initial study. The most probable reasons for this improvement are the provision of a community-based obstetric service, the early detection of cephalopelvic disproportion, awareness of the condition, immediate and adequate resuscitation once the diagnosis is established, and the performance of a total abdominal hysterectomy as definitive treatment in most cases.

Abnormal concentrations of prostaglandins in amniotic fluid during delayed labour in multigravid patients.

Concentrations of prostaglandins E (PGE), F2 alpha (PGF), 13,14-dihydro-15-keto prostaglandin F2 alpha (PGFM), 6-keto F1 alpha and thromboxane B2 were measured by specific radioimmunoassay in samples of amniotic fluid from 22 multigravid patients during labour. Normal labour in 10 patients was associated with a significant increase of PGE, PGF and PGFM with close correlation to cervical dilatation (P less than 0.05). In the 12 patients with clinically delayed labour, in the absence of cephalopelvic disproportion, there were significantly lower PGF (P less than 0.002) and PGFM (P less than 0.05) concentrations obtained while no differences were observed in the other prostanoids measured. Administration of oxytocin to the latter group to enhance labour did not have any effect on the concentrations of prostaglandins obtained in spite of an improvement in intrauterine pressures and accelerated progress of labour.

Obstructed labour.

PIP: The major cause of obstructed labor is cephalopelvic disproportion, which may be due to a small pelvis, a large baby, fetal malpresentation, a tight perineum, or abnormalities or tumors of the uterus, ovary, or vagina. Prior to obstruction in primigravidae the rate of cervical dilation in the active 1st phase of labor slows to less than 1 cm/hr. If intervention is not done, fetal anoxia, pressure necrosis, fetal death, and vesicovaginal fistula will occur. In multigravidae the cervix may achieve full dilation, but the fetus fails to descend in the birth canal, and the uterine contractions continue until the uterus ruptures. The primary treatment for obstructed labor is prevention through adequate prenatal care. In communities without hospital facilities, midwife-run satellite clinics with adequate transport for referrals are the next best option. Another option is the provision of mothers' waiting areas near the clinic or hospital, where expectant mothers can receive intrapartum supervision. Labor should be monitored with a partogram, so that abnormal cervical dilation can be detected early, and the patient can be transferred to hospital. Once there, the patient will require immediate parental fluids and antibiotics before surgery. If an anesthetist is not available, the surgeon should administer an epidural block. A stomach tube and antacid premedication should be used to prevent aspiration of gastric contents. The surgeon must decide on the most apposite mode of delivery: episiotomy, ventouse and forceps delivery, symphysiotomy, or cesarean section. Various cesarean section methods may be appropriate: extraperitoneal cesarean section when there is intrauterine infection in cephalic presentation, De Lee incision where there is transverse cephalic presentation or an uncorrectable constriction ring, or lower segment transverse incision. If the fetus is dead and the uterus has not ruptured, vaginal destruction of the fetus is preferable to cesarean section. If the uterus has ruptured, cesarean hysterectomy is the recommended action. Cesarean section is the recommended procedure for vertex, brow, and transverse presentations if the fetus is alive. A live fetus with hydrocephaly may be delivered vaginally after the head is drained, but symphysiotomy may be required.^ieng

Intrauterine-pressure studies in African nulliparae: normal labour progress.

Uterine activity was measured in 29 nulliparous African women, who were in the active phase of spontaneous labour, and who were delivered vaginally without supplementary oxytocin. A fluid-filled intrauterine catheter, an external strain gauge and a pressure-curve integrator were used to quantitate uterine activity. The rate of dilatation of the cervix from entry to the study to full dilatation of the cervix was greater than 1 cm/h; this constituted normal labour progress. In nulliparous African women the minimum level of uterine activity likely to be associated with a cervical dilatation rate of 1 cm/h was 1200 kPas/15 min and the median uterine activity level in the active phase of normal labour was 1824 kPas/15 min.

Intrauterine-pressure studies in African nulliparae: delay, delivery and disproportion.

Uterine activity was measured in 43 African nulliparae who were in the active phase of spontaneous labour and in whom delay in cervical dilatation had occurred. Details of labour were recorded on a partogramme, on which an alert and an action line had been drawn, and which were 2 h apart. Delay was defined as a cervical dilatation rate of less than 1 cm/h. Uterine activity was measured with a fluid-filled intrauterine catheter, an external strain gauge and a pressure-curve integrator. The uterine activity levels which were observed in association with delay are considerably less than those associated with normal labour progress. The uterine activity levels that were associated with pitocin augmentation after the action line and which resulted in vaginal delivery have been analysed. They were similar to the levels observed in normal labour. The uterine activity levels which were associated with 'failure to progress in labour' beyond the action line have also been analysed. It is argued that a minimum uterine activity level of 1800 kPas/15 min is required to fully test the cephalopelvic relation.

Factors associated with preterm labour and changes in the cervix before labour in twin pregnancy.

A total of 132 twin pregnancies in black African women were studied prospectively after 30 weeks gestation. Delivery occurred before 37 weeks in 32%. There was a trend (0.1 greater than P greater than 0.05) towards a higher preterm delivery rate in nullipara (57%), in women under the age of 20 years (60%) and in those with a height/weight ratio of greater than 2.5 (50%). The cervix was assessed with a score based on the length of the canal minus the dilatation of the internal os. In both term and preterm labour there was a significant relation between a cervical score of 0 or a decrease in cervical score and the onset of labour within the subsequent 14 days (P less than 0.001). By these criteria to predict impending labour, 60% of all labours that ensured within 14 days of the assessment would have been predicted with a 20% false positive rate. When nulliparae were excluded the predictive value of cervical assessment for preterm labour was 80% with a false positive rate of less than 5%. Plasma oestriol levels were significantly higher in the preterm labour group but had no clinical prognostic value.

Nuclear and cytoplasmic oestrogen receptors in squamous carcinoma of the cervix.

Nuclear and cytoplasmic oestrogen receptors (REN and REC) were sought in 5 normal cervices and in 43 specimens of squamous carcinoma of the cervix. All 3 tissues components of the 5 normal cervices contained both REN and REC. Thirty-five (81%) of the tumours contained receptors, but in only 9 (21%) were they found in both subcellular compartments. Twenty-four tumours (56%) had only REC and 2 had only REN. The potential therapeutic significance of these findings is not yet known, but it seems possible that tumours with an intact receptor mechanism might benefit from oestrogen therapy and have a more favourable prognosis.

The prediction of fetal growth retardation in twin pregnancy.

A total of 132 twin pregnancies first seen at less than 36 weeks gestation were studied prospectively to determine the epidemiological and anthropomorphic factors associated with single or dual fetal growth retardation; the clinical, biochemical and ultrasound serial measurements that are predictive of single or dual fetal growth retardation, and to design scoring systems for the prediction of fetal growth retardation. A number of factors were associated with an increased risk of fetal growth retardation, but the highest risk was present when there was an abnormality in both plasma oestriol and placental lactogen, and the biparietal diameter growth rates were divergent. Scoring systems were derived using multi-variant discriminant analysis for three clinical situations: the patient seen for the first or second time; where only clinical facilities exist and the patient was seen on three or more occasions; and where facilities exist for the biochemical tests of placental function and ultrasonic measurement of the biparietal diameters. The scoring system for the last situation had the highest predictive rate and the lowest false positive rate.

Effect of dihydralazine on the fetus in the treatment of maternal hypertension.

The effect on the fetus of lowering the maternal blood pressure with intravenous dihydralazine was studied in 33 patients with diastolic blood pressure of 110 mmHg or more. Nineteen patients showed fetal heart rate (FHR) decelerations coinciding with a fall in blood pressure. Thirteen of the 19 patients had growth-retarded fetuses, while only 1 of 14 patients who showed no FHR changes had a growth-retarded fetus (P greater than .005). Continuous FHR monitoring during the administration of dihydralazine helped identify the compromised fetus if it had been unrecognized at other observations.

Pelvic dimensions and the outcome of trial labour in Shona and Zulu primigravidas.

Pelvic contraction is very prevalent in Africa while radiological facilities to assess pelvic size and shape are seldom available. A trial of labour using simple guidelines on a cervicograph can enable the midwife to detect dysfunctional labour and can help medical staff to manage these problems. Radiological checks in 116 Black primigravid patients with dysfunctional labour demonstrated that an active trial of labour is accurate in determining which of these patients have marked disproportion requiring caesarean section, minimal disproportion requiring assisted delivery, or primary uterine inertia responding to oxytocic stimulation. The role of radiological pelvimetry in African obstetrics is discussed, and the radiological features of the Shona and Zulu pelves in this series are described.

The effect of fetal head compression and fetal acidaemia during labour on human fetal cerebral function as measured by the fetal electroencephalogram.

We investigated the effect of head compression and acidaemia during labour in 25 African primigravidae. Evidence that head compression had occurred during labour was confirmed by both clinical and radiological means at the end of a trial of labour. No significant difference could be demonstrated in the quantity of fetal electroencephalogram (EEG) abnormality that occurred in the groups with marked head compression as compared to the groups without marked head compression. Deterioration in the fetal EEG to a flat record known as electrocerebral silence (ECS) was associated with the development of acidaemia. As fetal heart rate (FHR) decelerations appeared the percentage of ECS in the fetal EEG record increased significantly (P less than 0.05), and likewise, as fetal acidaemia developed a highly significant increase in ECS in the fetal EEG was demonstrated (P less than 0.001). We concluded that in the management of trial of labour there was no significant deleterious change in the fetal EEG as a result of head compression, unless fetal acidaemia supervened. However, in the majority of these cases a significant increase in ECS to more than 20 per cent occurred in association with only moderate acidaemia (pH 7.25 to 7.30).