843to six weeks before the clinical onset of the syndrome. Five had further samples taken after the diagnosis of pre-eclampsia : initially TNF-a was still undetectable but rose later in three (80, 156, 250 pg/ml).This rise was not seen until one to two weeks after preeclampsia was diagnosed. In the nine women with established pre-eclampsia, TNF-a was detected in only two (80 and 650 pg/ml): in another two of these women, serial samples were obtained, but TNF-(x was still not detectable one to two weeks after pre-eclampsia was diagnosed. A rise in TNF-a was not related to the stage in pregnancy at which the onset of preeclampsia occurred, nor to its seventy. TNF-a was not identified in normal controls at similar gestations to the pre-eclampsia groups, but it was detected in one of the 22 at term (80 pg/ml). E-selectin concentrations were not significantly different between the normal and the pre-eclamptic pregnancies, neither before nor after pre-eclampsia was diagnosed.Like Vince et al., our study does not demonstrate a role for TNF-a in initiating pre-eclampsia, nor does it suggest that IL-1 is implicated. It has, however, shown that TNF-a may well be involved in the process of pre-eclampsia once the syndrome is clinically established. Neonatal respiratory morbidity and mode of delivery at term: influence of timing of elective caesarean section
J. W. Meekins
Department of Obstetrics and
Sir,We read with interest the article by Morrison et al. (Vol 102, February 1995). We believe they are correct in recognising that respiratory morbidity in term infants has not received the attention it merits. We wish to report a small study at our hospital in 1992 undertaken in an attempt to quantify the problem and consider options for its prevention. We reviewed those infants born after 34 completed weeks of gestation admitted to the Special Care Baby Unit with a diagnosis of respiratory distress syndrome (RDS), over an 18 month period. We used a similar system of diagnostic and exclusion criteria to the Cambridge group. As expected, the incidence of RDS declined towards term reaching a level of 2.3/1000 deliveries at 38 completed weeks. The group that caused most concern were those infants born by pre-labour caesarean section (emergency and elective) in whom the incidence was 24.1/1000. We then looked at just elective caesarean sections and found the incidence of RDS to be 143/1000. This is less than the Cambridge figure, probably because of the exclusion of transient tachypnoea of the newborn. Although none of the babies died, we were concerned about the morbidity; 48% of these babies required assisted ventilation and the average length of stay on the neonates unit was 11 days.We considered how this might be prevented and examined the role of amniocentesis with delay of delivery until the lecithin: sphingomyelin ratio indicated pulmonary maturity. Although amniocentesis at term under ultrasound control is a relatively safe procedure (Picker et al. 1976) (ACOG 1991). In view of the now well-described morbidity and possib...