D. M. F. Gibb

Failed Induction of Labour

Editorial Comment: There is an important take away message in this paper–namely that 65% of nulliparas with an unfavourable cervix who had induction of labour performed by amniotomy and simultaneous oxytocic infusion came to Caesarean section, two‐thirds because of failed induction.

The effect of parity on uterine activity in labour

Summary. Uterine activity was studied in 40 multiparous Singapore women of Chinese origin who were in normal labour and had a normal delivery. A catheter tip pressure transducer coupled with a uterine activity integrator was used to quantify uterine activity. Normal labour progress was defined as labour progressing within 2 h to the right of a line drawn on the partogram at 1 cm/h in the active phase of labour. A wide range of activity was observed. The median level of uterine activity rose from 815 kPas/15 min at 3 cm dilatation to 1731 kPas/15 min at 9 cm dilatation with an overall median level of 1130 kPas/15 min. The 10th centile value rose from 430 kPas/15 min at 3 cm dilatation to 923 kPas/15 min at 9 cm dilatation. Profiles of dilatation‐specific activity values were constructed. These values were significantly lower than in a comparative group of nulliparous patients. The parous uterus requires to expend significantly less effort to effect normal vaginal delivery than its nulliparous counterpart.

Characteristics of uterine activity in nulliparous labour

Summary. Uterine activity was studied in 40 nulliparous Chinese women who were in normal labour and had a normal delivery. A catheter‐tip pressure transducer coupled with a uterine activity integrator was used to observe and quantify uterine activity. Normal labour progress was defined as labour progressing within 2 h to the right of a line drawn at 1 cm/h in the active phase. A wide range of uterine activity was recorded with varying degrees of co‐ordination. The minimum level of uterine activity likely to be associated with labour progress was 650 kPas/15 min at 3 cm cervical dilatation. The median level in the active phase of normal labour was 1440 kPas/15 min. There was a strong correlation between measurements in kPas/15 min and Montevideo units/15 min (r= 0.71, P0.001). No significant increase was found in basal tone.

Nile stimulation in late pregnancy causing uterine hyperstimulation and profound fetal bradycardia

Nile stimulation in late pregnancy may cause oxytocin release sufficient to give uterine hypertonus and danger to the fetus. Three patients are described in whom nile stimulation caused a marked but temporary fetal bradycardia.

Uterine activity during spontaneous labour after previous lower-segment caesarean section

Summary. Uterine activity was measured in three groups of labouring women who previously had a caesarean section (CS): group A included women with a previous elective CS before labour or in the early latent phase of labour and no previous vaginal delivery; group B included women with a CS in the active phase of labour and no previous vaginal delivery; group C included women with a CS and a vaginal delivery either before or after the abdominal delivery. The active contraction area profiles in the three groups were compared with those of matched control groups of nulliparae and multiparac without a uterine scar. Group A had a uterine activity profile similar to that in control nulliparae and significantly higher than that in control multiparae. The uterine activity in group B was less than that in matched nulliparae but was similar to that in matched multiparae. Group C had significantly less uterine activity than matched nulliparae but a similar profile to that in the matched multiparae. Progress of labour into the active phase in the previous pregnancy reduces the uterine activity profile in subsequent labour. Women who had had a vaginal delivery either before or after the CS (group C) exhibited uterine activity profiles similar to multiparae, suggesting that an intact scar did not affect the uterine function.

Total uterine activity in induced labour—an index of cervical and pelvic tissue resistance

Summary. Uterine activity was studied during labour induced using an automatic infusion system (AIS) or a peristaltic infusion pump (IVAC) to administer oxytocin. In the 110 patients who achieved vaginal delivery the total uterine activity required to effect full dilatation of the uterine cervix was found to vary according to parity and cervical score but not according to mode of oxytocin infusion. Irrespective of whether the uterine activity level per 15 min was maintained at between 700 and 1500 kPas or at between 1500 and 2000 kPas, the total uterine activity was similar the lower levels being compensated for by a longer duration. Fetal outcome, in terms of 1‐and 5‐min Apgar scores and umbilical vein blood pH, was unaffected by the level of uterine activity. The cervical and pelvic tissue resistance varies according to parity and cervical score and the uterus has to achieve a certain total uterine activity in induced labour which is best achieved by maintaining optimal uterine activity levels of 1500–2000 kPas/15 min to effect vaginal delivery of the baby in good condition in optimal time.

A comparative study of methods of oxytocin administration for induction of labour.

Summary. Equipment has become available for the automatic infusion of oxytocin in a closed loop system for the induction of labour. This system was compared with manual administration of oxytocin by peristaltic infusion pump, the dosage being based on data derived from an intrauterine catheter or by clinical assessment of uterine activity. A total of 121 patients classified according to parity and cervical score were allocated to an automatic infusion system (AIS) or a peristaltic infusion pump system. Patient characteristics were similar in both groups. Labour was significantly longer in those induced by automatic infusion system particularly in nulliparae and patients with poor cervical scores. In 53.3% of the nulliparae with poor cervical scores the automatic infusion system proved inadequate to effect vaginal delivery. Neonatal outcome was similar in both groups. Automatic infusion of oxytocin by the present system increased the length of induced labour and had no statistically significant effect on neonatal outcome, conferring no advantage over a more traditional method of oxytocin administration.

Transient blindness associated with pregnancy‐induced hypertension. Case reports

Transient blindness with pregnancy-induced hypertension without other neurological symptoms is a rare phenomenon, and few cases have been reported in the world literature (Gandhi e( al. 1978; Beck ef al. 1980; Chew & Tay 1981). Permanent loss of vision with severe preeclampsia has also been documented (Sonimerville-Large 1950; Carpenter et al. 1953). We report three cases of transient blindness associated with pregnancy-induced hypertension out of 30 867 deliveries in the University Unit, Kandang Kerbau Hospital, Singapore during the period 198C-1983, when the incidence of hypertensive disease of pregnancy was 6.6% and that of eclampsia was 0.13%.

Uterine activity in spontaneous labour with breech presentation.

EDITORIAL COMMENT: In this unusual and interesting study the authors found that uterine activity in patients with breech presentation is similar to that in patients with vertex presentations, when controlled for parity (nulliparas versus multiparas). The study did not consider the type of breech presentation, although one might expect labour to be more coordinate and effective with a breech with extended legs than with a complete breech. It is interesting to note that the authors practise amniotomy in the active phase of labour when the breech presents ‘provided that cord presentation or a high presenting part is excluded’. In this group of patients the authors did not employ either epidural analgesia or oxytocin enhancement of labour. The authors make the point that normal uterine activity in patients with breech presentation does not guarantee safe breech delivery. Readers should note that in this series criteria for inclusion included normal pelvic and fetal dimensions, and spontaneous onset of labour.

Uterine activity in myotonia dystrophica. Case report.

The patient was a 28-year-old woman in her fourth pregnancy. She has had myotonia dystrophica since the age of 4 years diagnosed by electromyographic (EMG) investigations and abnormal serum creatinine phosphokinase levels. One of her sisters also has the disease but not her parents or two other siblings. Her first pregnancy resulted in a growthretarded (1800 g) macerated stillbirth at term 6 years ago. The second pregnancy terminated in spontaneous abortion at 3 months gestation. Her third pregnancy was complicated by massive polyhydramnios with preterm labour at 32 weeks when 2.5 litres of amniotic fluid were drained with membrane rupture. The baby was born by caesarean section for fetal distress under 0.5% bupivicaine lumbar epidural anaesthesia. The baby had an Apgar score of 1 at 1 min, 2 at 5 min, and died 24 h later. Within hours of surgery her temperature rose to 39°C and was controlled by tepid sponging. The possibility of malignant hyperpyrexia was entertained but was not confirmed due to the lack of facilities to perform caffeine sensitivity test. In this, her fourth pregnancy, she was booked at 20 weeks and had eight subsequent antenatal visits. Initial ultrasound confirmed the period of gestation and excluded major fetal abnormality. Serial ultrasound examination for growth of the fetus was satisfactory and there was no evidence of excess amniotic fluid. She complained of generalized weakness during this pregnancy but there was no paraesthesia, sensory defect or visual problems. She had no frontal balding but had poor facial expression and symmetrical wasting of both arms and legs. Cardiovascular and respiratory systems were normal. Investigations revealed normal ECG, haemoglobin, phosphate, calcium, urea potassium, sodium and chloride levels. Serum