Naren B. Patel

An audit of the obstetric outcome of 148 consecutive pregnancies from assisted conception : implications for neonatal services

Objective To assess the outcome of pregnancy following assisted conception.

Non‐stress antenatal cardiotocography‐a prospective randomized clinical trial

Summary. A randomized controlled trial examined the effects of non‐stress antepartum cardiotocography on obstetric management and assessed its usefulness as a diagnostic test of fetal compromise. Daily cardiotocograph recordings were made in 396 antenatal patients at increased risk of fetal compromise but were withheld from the clinicians responsible for care in half the cases. The frequency of intrapartum fetal distress and low Apgar score was similar in the two groups. The three normally‐formed perinatal deaths all occurred in the revealed group but in only one case could earlier obstetric intervention have altered the outcome. Availability of non‐stress cardiotocography was not associated with an increased rate of induction of labour or caesarean section.

Mortality and morbidity in infants born between 20 and 28 weeks gestation

Of 149 infants with ultrasound evidence of gestadonal age, born in Ninewells Hospital at between 20 and 28 weeks gestation over a 5‐year period, 50 were alive at birth. Of these infants, 21 died within 1 week, a further three died within 1 month and a further two within 18 months. Of the 24 survivors, 8 (33%) have significant handicap. The obstetric factors leading to delivery and the mode of delivery are discussed.

Umbilical artery velocity waveforms: poor association with small‐for‐gestational‐age babies

Summary. A total of 205 high‐risk pregnancies was studied using coninuous wave Doppler ultrasound examination of the umbilical artery to investigate the ability of the test to detect small‐for‐gestational‐age (SGA) infants. The waveforms were analysed by calculating a ratio of the peak systolic to end diastolic frequency (A/B ratio). An A/B ratio >95th centile from our derived normal values was classified as abnormal. Three outcome variables were examined: birthweight for gestational age, the standard deviation birthweight score and the ponderal index. Although of the 56 pregnancies with an abnormal Doppler result 34 (61 %) were associated with a SGA infant, only 41% of all the SGA infants had an abnormal Doppler result. Alternative measures of growth, the ponderal index and the SD birthweight score, showed that on average the babies in the Doppler abnormal group were smaller than those in the Doppler normal group, but the overlap between the normal and abnormal groups was large. Therefore although Doppler ultrasound appears to identify groups of smaller babies, it does not identify individual pregnancies where the baby will be small at birth.

In‐vivo accuracy of ultrasound measurements of intrauterine ume in pregnancy

Summary. The accuracy of ultrasonic measurements of intra‐amniotic ume using a parallel planimetric area method was assessed in 18 women by comparison against different measures of the same ume space. In nine patients undergoing second‐trimester termination of pregnancy amniotic fluid ume was measured using a dye dilution method and fetal ume was measured by either water displacement or calculated from fetal weight. The estimated intra‐amniotic ume by this method was not significantly different from the ultrasonic measurement. In one patient who had a hysterotomy, fetal and amniotic fluid umes showed a difference of 1.01% between ultrasonically‐measured and actual intra‐amniotic ume. In eight patients studied in the third trimester the mean difference between ultrasonic and estimated intra‐amniotic ume at delivery was 6.2%.

Epidural analgesia and its effect on umbilical artery flow velocity waveform patterns in uncomplicated labour and labour complicated by pregnancy-induced hypertension

Umbilical artery flow velocity waveforms were obtained using continuous-wave Doppler ultrasound to examine the effect of epidural analgesia on peak systolic/least diastolic ratio (A/B ratio) in 38 women in uncomplicated labour, and 12 women with pregnancy-induced hypertension (PIH). In the uncomplicated group there was no significant change in A/B ratio after epidural analgesia, but in the PIH group there was significant correlation between the fall in mean blood pressure and the fall in A/B ratio at 30 min after induction of epidural analgesia (r = 0.85, p less than 0.001). This suggests that epidural analgesia in PIH is associated with a reduction in placental resistance and may be beneficial to the fetus.

The predictive value of fetal breathing movements in the diagnosis of preterm labour

Summary. A real time ultrasound investigation was performed on 64 patients who presented in threatened preterm labour. Fetal breathing movements (FBM) were absent in 17 patients, all of whom were delivered within 56 h. FBM were present in 47 patients of whom five were delivered within 56 h from examination and four of these had spontaneous rupture of membranes and/or chorioamnionitis. In 33 the pregnancy continued for at least 1 week. Two of the fetuses with false negative results showed a distinct breathing pattern different from the rest of the study group. This suggests that pattern recognition of fetal breathing might improve the specificity of this investigation.

Neonatal cerebral doppler flow velocity waveforms in the pre-term infant with cerebral pathology

In a longitudinal study of 217 infants delivering at < 37 completed weeks gestation, Doppler flow velocity waveforms were obtained, and resistance index (RI) values calculated from the middle (MCA) and anterior (ACA) cerebral arteries during the first 10 days of life. Sixty infants demonstrated ultrasound evidence of cerebral pathology, of which five cases were congenital, and an additional 13 cases were complicated by patent ductus arteriosus during the study period. The Doppler data obtained during the first week of life from the remaining 42 infants who developed cerebral pathology, and 15 infants who had evidence of metabolic acidosis at delivery without ultrasound evidence of cerebral pathology were compared with local reference data obtained from non-acidotic infants with normal cranial ultrasound from 24 h of age. In those infants who had evidence of minor periventricular haemorrhage alone (Grade I/II PVH), there was no significant difference between the ACA or MCA RI during the study period compared with the reference data. In those groups of infants who demonstrated major PVH (Grade III/IV) or persistent periventricular flares, the ACA and MCA RI was found to be consistently significantly higher than the reference group throughout the study period. In those infants who developed ultrasound evidence of periventricular cystic leukomalacia (PVCL), the MCA RI was significantly lower than the reference data between 48 and 72 h of age, there being no significant difference in the ACA RI. The Doppler findings in those infants with evidence of metabolic acidosis at delivery (umbilical arterial pH < 7.20; BD > 8 mmol/l) but with normal ultrasound findings were similar to those infants who developed PVCL, namely a significant fall in MCA RI between 48 and 72 h of life, with no significant difference in the ACA RI during the study period. These findings suggest that variable changes in cerebral vascular resistance occur with the evolution of, or as a consequence of the development of cerebral pathology in the pre-term infant, and these changes of increased and decreased vascular resistance are discussed. Further investigation of the changes occurring in the cerebral circulation in the early neonatal period of infants who develop PVCL is required to clarify the vascular changes taking place, but if the findings of this study are confirmed, this technique may provide a means of identifying infants at risk of developing ischaemic cerebral pathology at an early stage when it may be possible to initiate therapeutic intervention to limit the cerebral damage.

Mothering problems and child morbidity amongst mothers with emotional disturbances

Abstract. In a study of 1,955 primigravidae who gave birth to a live singleton baby, 227 (11.6%) scored ‘positive’ 17 +) in an antenatal Health Questionnaire enquiring into pre‐pregnancy emotional disturbances. This group of mothers had more frequent depression, and this was of longer duration after their delivery compared with those scoring less than 7 (≤6). Those scoring 7+ were less likely to breast‐feed and the infants were more often ill during the first year of life. There were also differences in ‘minor obstetric complications’ between the two survey groups. This suggests that the application of this Health Questionnaire antenatally can identify emotionally vulnerable women, who could benefit from support and education during the antenatal period.

The validity and reliability of real-time ultrasound estimation of bladder volume in postnatal women

SummaryTwenty-eight women following forceps delivery were recruited to assess the validity of the ultrasonic estimation of bladder volumes. A further 20 postpartum women with in-dwelling catheters were recruited to assess the reliability of the ultrasound method. The in limit of visualisation of urine in the bladder by ultrasound appeared to be approximately 25 ml. 1 he intraelass correlation coefficients for the bladder volume estimated by ultrasound versus those obtained by urethral catheterisation was 0–98. indicating a high degree of correctness in the ultrasonic measurements (validity). The mean difference between bladder volumes measured by two independent observers for bladder volumes between 40 and 120 ml was + 2–4 ml and the corresponding limits of agreement (mean i s.d.) were -13–6 to ±18–3 ml. The overall intraelass correlation coefficient for bladder volumes independently measured using ultrasound by two observers was 0–99, indicating a high degree of agreement between the two observers (relia...