James F. Pearson

Fatal shoulder dystocia: a review of 56 cases reported to the Confidential Enquiry into Stillbirths and Deaths in Infancy

Objective To use information collected by the Confidential Enquiry into Stillbirths and Deaths in Infancy to help obstetric, midwifery and paediatric practice in the management of shoulder dystocia.

Shoulder dystocia: what happens at the next delivery?

women in whom pyuria greater than 10 x 10”l is considered significant. These findings should not be extrapolated to pregnant women who often have a vaginal discharge or a show which may be responsible for the presence of white cells. It is all too easy to attach a label of urinary tract infection to a patient’s condition and then fail to act as the symptoms and signs change. The neonatal death due to overwhelming herpes infection in this series might have been prevented by making the correct diagnosis antenatally. More frequent conditions which also may be mistaken for a urinary tract infection include premature labour and placental abruption, neither of which may be obvious on initial presentation. A realisation that diagnoses based on the presence of pyuria may be incorrect would encourage doctors and midwives to review the patients’ condition regularly, especially if improvement is not seen in response to antibiotic therapy. Of the four patients with a proven urinary tract infection, three presented with dysuria, and the other had classical pyelonephritis with loin pain, fever, and rigors. Dysuria (relative risk (RR) = 26.60, 95 % CI 2.95-239.89) and loin pain (RR = 12-45, 95 Yn CI 1.94-80.08) were the only features that were significantly associated with a positive midstream urine culture. The presence of urinary frequency, lower abdominal pain, back pain, preterm contractions, and pyrexia were not significantly associated with a positive midstream urine culture. Four patients with pyuria and no significant growth on culture had anti-bacterial substances detected in their urine. It was not possible to determine if any of these patients had a urinary tract infection.

The effect of continuous lumbar epidural analgesia on the acid-base status of maternal arterial blood during the first stage of labour.

The maternal arterial acid‐base status and arterial lactate concentrations were measured in parturient women before the onset of clinically detectable labour, at the beginning of the active phase of labour and at full dilatation of the cervix. Of the patients studied, 43 were provided with continuous lumbar epidural analgesia, and 30 were managed conventionally. Epidural analgesia was associated with less alteration in acid‐base status during the first stage of labour than was seen in suitable controls. The possible cause of this finding is discussed briefly.

THE EFFECT OF CONTINUOUS LUMBAR EPIDURAL ANALGESIA UPON FETAL ACID‐BASE STATUS DURING THE FIRST STAGE OF LABOUR

The acid‐base status was measured in parturient women and their infants before the onset of clinically detectable labour, at the beginning of the active phase of labour and at full dilatation of the cervix. All patients conformed to the criteria of the “Clinically Acceptable Ideal Case” (Crawford, 1965). Of the 39 patients studied, 17 were provided with continuous lumbar epidural analgesia, and 22 were managed conventionally. Epidural analgesia was associated with less alteration in fetal and maternal acid‐base status during the first stage of labour and there was also closer feto‐maternal acid‐base correlation in patients receiving epidural block. The possible causes of these findings are briefly discussed.

A SIX-POINT SCORING SYSTEM FOR ANTENATAL CARDIOTOCOGRAPHS

A six‐point scoring system for antenatal cardiotocography based upon baseline fetal heart rate (FHR) and FHR response to fetal movements and Braxton‐Hicks contractions has been described and tested in 89 patients. The ‘six‐point score’ obtained within 24 hours of delivery or death of the fetus (D—1) was shown to be strongly associated both with the one‐minute Apgar score and the nutritional status of the infant as reflected by centile birth weight. In 21 patients whose D—1 ‘six‐point score’ was 4 or less, analysis of the cardiotocographs performed on the previous day (D—2) showed that 14 infants already showed evidence of hypoxia. In the remaining seven patients, however, the previous days six‐point score had been normal (5 or 6); in six of these patients a persistently low daily fetal movement count or placental abruption led to repeat cardiotocography. Hypoxia affected the three components of the score in a progressive manner. Firstly there were alterations in the response of the FHR to Braxton‐Hicks contractions followed by changes in the FHR response to fetal movements. Finally, fetal movements ceased and baseline FHR changes occurred mainly in the form of a tachycardia. The method of scoring was simple to use and could standardize reporting.

FETAL ACTIVITY AND FETAL WELL BEING: AN EVALUATION

The clinical value of the 12-hour daily fetal movement count (DFMC) as a test of antepartum fetal wellbeing was assessed. The lowest 2-5% of 1654 DFMCs recorded by 61 women who subsequently delivered healthy infants fell below 10 movements per 12 hours. This level was taken as the lower limit of normal for clinical purposes. A normal DFMC in a population at risk was associated with a satisfactory fetal outcome. A low DFMC was associated with a high incidence of fetal asphyxia, and when fetal death occurred fetal movements rapidly diminished and stopped 12 to 48 hours before death. The DFMC is a generally applicable method of monitoring fetal welfare during pregnancy which provides an inexpensive adjunct or even an alternative to the more expensive placental function tests in current use.

THE EFFECT OF CONTINUOUS LUMBAR EPIDURAL ANALGESIA ON MATERNAL ACID‐BASE BALANCE AND ARTERIAL LACTATE CONCENTRATION DURING THE SECOND STAGE OF LABOUR

The effects of continuous lumbar epidural analgesia on maternal arterial acid‐base balance and arterial lactate concentration in the second stage of labour were investigated. Although primiparae became more acidotic than multiparae, their rates of increase in acidosis were virtually identical. Epidural analgesia depressed the bearing‐down reflex and thus diminished the rate of production of lactate and the degree of maternal metabolic acidosis.

Posture and epidural block in pregnant women at term. Effects on arterial blood pressure and limb blood flow.

Upper and lower limb blood flow was measured in 4 fullterm pregnant women in the left lateral and supine positions before and after epidural block. Radial artery mean blood pressure was recorded in 6 full term pregnant women under the same conditions. Before epidural block there was a much greater reduction in lower limb blood flow (39-1%) than in upper limb blood flow (13-5%) when women moved from the lateral to the supine position; this was probably the result of aortic compression. Mean radial artery pressure increased slightly by 4-6% due to maternal overcompensation in the upper part of the body. After epidural block, patients in the lateral position had a mean rise in lower limb blood flow of 25% and a reduction in upper limb blood flow of 37-2%. The mean arterial pressure remained unchanged. In the supine position there was no further reduction of upper limb blood flow; this was accompanied on average by a 9% fall in mean radial arterial pressure indicating decompensation in the mother. The leg blood flow fell less, 26-9% than before epidural block. In the supine position, a greater flow to the legs, associated with a decreased mean arterial pressure, would be expected to lead to a diminution in placental perfusion, which is the probable mechanism for foetal decompensation. Therefore the supine position should be avoided with an epidural block. In other patients it would be wise not to rely upon maternal compensatory mechanisms.

THE EFFECT UPON THE FETUS OF AN OXYTOCIN INFUSION IN THE ABSENCE OF UTERINE HYPERTONUS

The effect of oxytocin administration by the Cardiff Infusion System upon fetal acid‐base balance and the continuous fetal heart rate pattern was measured in ten “Clinically Acceptable Ideal” multigravidae and ten controls. In the absence of uterine hypertonus oxytocin administration was not associated with evidence of fetal asphyxia during the first stage of labour.