G. M. Stirrat

DO APGAR SCORES INDICATE ASPHYXIA

Abstract In a prospective study of 1210 consecutive deliveries the relation between the Apgar scores and the acid-base status of the babies at birth was assessed. Only 21% ofthe babies with a 1 min Apgar score

The Bristol third stage trial: active versus physiological management of third stage of labour.

OBJECTIVE--To compare the effects on fetal and maternal morbidity of routine active management of third stage of labour and expectant (physiological) management, in particular to determine whether active management reduced incidence of postpartum haemorrhage. DESIGN--Randomised trial of active versus physiological management. Women entered trial on admission to labour ward with allocation revealed just before vaginal delivery. Five months into trial high rate of postpartum haemorrhage in physiological group (16.5% v 3.8%) prompted modification of protocol to exclude more women and allow those allocated to physiological group who needed some active management to be switched to fully active management. Sample size of 3900 was planned, but even after protocol modification a planned interim analysis after first 1500 deliveries showed continuing high postpartum haemorrhage rate in physiological group and study was stopped. SETTING--Maternity hospital. PARTICIPANTS--Of 4709 women delivered from 1 January 1986 to 31 January 1987, 1695 were admitted to trial and allocated randomly to physiological (849) or active (846) management. Reasons for exclusion were: refusal, antepartum haemorrhage, cardiac disease, breech presentation, multiple pregnancy, intrauterine death, and, after May 1986, ritodrine given two hours before delivery, anticoagulant treatment, and any condition needing a particular management of third stage. INTERVENTIONS--All but six women allocated to active management actually received it, having prophylactic oxytocic, cord clamping before placental delivery, and cord traction; whereas just under half those allocated to physiological management achieved it. A fifth of physiological group received prophylactic oxytocic, two fifths underwent cord traction and just over half clamping of the cord before placental delivery. ENDPOINT--Reduction in incidence of postpartum haemorrhage from 7.5% under physiological management to 5.0% under active management. MEASUREMENTS AND MAIN RESULTS--Incidence of postpartum haemorrhage was 5.9% in active management group and 17.9% in physiological group (odds ratio 3.13; 95% confidence interval 2.3 to 4.2), a contrast reflected in other indices of blood loss. In physiological group third stage was longer (median 15 min v 5 min) and more women needed therapeutic oxytocics (29.7% v 6.4%). Apgar scores at one and five minutes and incidence of neonatal respiratory problems were not significantly different between groups. Babies in physiological group weighed mean of 85 g more than those in active group. When women allocated to and receiving active management (840) were compared with those who actually received physiological management (403) active management still produced lower rate of postpartum haemorrhage (odds ratio 2.4;95% CI1.6 to 3.7). CONCLUSIONS--Policy of active management practised in this trial reduces incidence of postpartum haemorrhage, shortens third stage, and results in reduced neonatal packed cell volume.

MATERNAL SERUM-ALPHA-FETOPROTEIN AND LOW BIRTH-WEIGHT

High maternal serum-alpha-fetoprotein (A.F.P.) concentrations in the first half of pregnancy were associated with prematurity and high perinatal mortality. 94 singleton pregnancies without neural-tube defects but with A.F.P. levels equal to or greater than three times the normal median resulted in the birth of infants weighing, on average, 357 g less than controls (P less than 0-001). The mean head circumference of the infants was also smaller than that of the controls. The 1 stillbirth and 3 neonatal deaths yielded a mortality-rate more than three and a half times that for singleton births without neural-tube defects at the same hospital in the years 1974-76. The results suggest that some pregnant women who will deliver low-birth-weight infants at high risk of perinatal death may be identified by means of serum-A.F.P. measurement early in pregnancy.

SMALL BIPARIETAL DIAMETER OF FETUSES WITH SPINA BIFIDA: IMPLICATIONS FOR ANTENATAL SCREENING

The biparietal diameter of 20 fetuses with spina bifida was measured during pregnancy by ultrasound scanning, mainly in the second trimester. The mean result was 0.83 cm smaller than the value based on 186 unaffected pregnancies at the same gestational ages (P<0.001), suggesting that spina bifida fetuses are growth retarded. The practical consequence of this finding is that the routine use of ultrasound in pregnancy will increase the sensitivity of AFP screening for open spina bifida at 16 to 18 weeks gestation from 79 per cent as estimated by the UK Collaborative AFP Study to about 90 per cent or more.

Circulating immune complexes in pre-eclampsia.

Sixteen patients with severe pre-eclampsia had more IgG-containing and C1q-binding circulating soluble immune complexes than did 16 matched women with normal pregnancies. The clinical features of preeclampsia may be explained by damage due to such complexes, although raised complex levels were also present in a few women with normal pregnancies. As immune complexes are so heterogenous in terms of the type of antigen, class and subclass of immunoglobulin, size, and complement-binding capacity, further investigations are needed to determine their role in normal and pre-eclamptic pregnancies.

ANTENATAL SCREENING IN OXFORD FOR FETAL NEURAL TUBE DEFECTS

Between May 1975 and the end of 1977, 6443 antenatal patients were screened mainly between 16 and 22 weeks of pregnancy for neural tube defects (NTDs) at the John Radcliffe Hospital, Oxford, by maternal serum alpha‐fetoprotein (AFP) measurement; a take‐up of 72 per cent. Seventeen out of 18 (94 per cent) patients with open NTD pregnancies (9 out of 9 with anencephaly and 8 out of 9 with open spina bifida) had positive screening tests, and all except one were offered and accepted a termination of pregnancy. Two hundred and forty‐five (3.8 per cent) patients with unaffected pregnancies also had positive screening tests, although only 1 4 per cent had an amniocentesis. Following ultrasonography, about 50 per cent of patients with unaffected pregnancies with positive screening tests were not offered an amniocentesis because they had a multiple pregnancy or their gestational age had been underestimated. The odds of having a fetus with an NTD among the women who had an amniocentesis was about 1 to 6 (1 to 11 for open spina bifida alone). Two apparently normal pregnancies were terminated. A survey of the acceptability of the screening programme among a consecutive sample of 73 patients who knew that they had a positive screening test revealed that all except one had no objection to screening in general, and 68 (93 per cent) wanted to be tested again in a future pregnancy. The approximate direct cost of the programme was £2 to £3 per patient screened, or about £l000 per NTD detected (about £2200 per open spina bifida detected).

MATERNAL SERUM ALPHA‐FETOPROTEIN AND SPONTANEOUS ABORTION

The relationship between spontaneous abortion and maternal serum alpha‐fetoprotein (AFP) levels was investigated between 9 and 25 weeks of pregnancy. Seven out of 126 (5·6 per cent) women who had spontaneous abortions had raised maternal serum AFP levels at their antenatal booking visit compared to 4 out of 247 (1·6 per cent) control patients who were delivered of single liveborn infants, a statistically significant difference. The raised AFP concentrations were, however, associated with spontaneous abortion only if the serum samples had been taken immediately before, or at sometime after the abortion was first clinically suspected. This suggests that high levels do not predict the development of abortion in women who have not already threatened to abort. It is therefore unlikely that women who who have not already threatened to abort. Therefore, when maternal serum AFP levels are used to screen for fetal neural tube defects, women referred for a diagnostic amniocentesis on account of a high level are unlikely to have been selected on the basis of a tendency to abort.

MATERNAL SERUM ALPHA‐FETOPROTEIN AND BIRTH WEIGHT IN TWIN PREGNANCIES

In 102 twin pregnancies the mean birth weight of each pair showed a statistically significant negative association with maternal serum alpha‐fetoprotein (AFP) levels early in pregnancy. Women with AFP levels of four or more times the median value for singleton pregnancies gave birth to infants with a median birth weight 660 g less than that of infants born to women with AFP levels between 1·0 and 1·5 times the median for singleton pregnancies. Maternal serum AFP has been shown to be an early predictor of low birth weight delivery in singleton pregnancies. Our results indicate that this is also true in twin pregnancies.

Raised maternal serum AFP, oligohydramnios and poor fetal outcome.

Six women who had an ultrasound scan examination in early pregnancy on account of a high serum alpha‐fetoprotein level were noted to have little or no amniotic fluid. This paper gives details of the six pregnancies, two of which were extrauterine; only one of the six infants survived.

CLINICAL DILEMMAS ARISING FROM THE ANTENATAL DIAGNOSIS OF NEURAL TUBE DEFECTS

Eight case histories are presented which demonstrate clinical problems associated with the antenatal screening for and diagnosis of neural tube defects. It is suggested how some of these problems might be avoided in future.