Authors’ reply

Abstract

A metaanalysis of the effect of estrogen replacement therapy on the risk of breast cancer. JAMA 265, [1985][1986][1987][1988][1989][1990]. Authors' replySir, We accept, and state in our text Smellie & Thomas (1993), that it is not possible to be confident about the long term safety of hormone replacement therapy (HRT) in the same way as it is in the short term therapy group of patients treated for less than ten years. Grady and Ernster (1991) amalgamated the findings of all the recent analyses and suggest that a large trial, producing results that differ markedly from those found in previous trials, would be required to alter the conclusion that short term use of HRT causes few, if any, extra cases of breast cancer. Although unaware of the planned trials into the safety of HRT referred to, we still doubt the ability of such trials to be double-blind because of the obvious manifestations of HRT. We shall welcome their results in 15 years, and in the meantime have to accept the limitations of observational trials. A randomised trial of 45 minute and 15 minute incremental oxytocin infusion regimes for the induction of labour in women of high paritySir, We read with interest the paper by Orhue (February 1993) which is also relevant to obstetricians in developed countries. The paper demonstrates the risks of 15 minute compared with 45 minute oxytocin infusion increments for women of high parity. These risks outweigh the slight delay in induction-delivery interval. We believe the conclusions can be extended. It has been demonstrated that in primiparous and multiparous women, regimens involving dose increment intervals less than 30 minutes have no effect on the induction-delivery interval and are associated with an increased incidence of hyperstimulation and more frequent caesarean section due to fetal heart rate abnormalities ( (1992) is welcome in that it helps to shift the focus of attention away from single assessment of fetal size to dynamic assessment of size when growth is to be assessed. I find the comments of Gardosi (1993) rather unhelpful as he seems to have missed the whole point of this wellconducted study. In being fixated with the use of "appropriately derived" birthweight charts, he has overconcentrated his criticisms on the choice of birthweight charts. Furthermore, his criticism that there were only 10 small for gestational age (SGA) babies in the study suggests that he equates SGA with IUGR, the very point that this study was trying to get away from. The demonstration that a falloff in growth amongst appropriate for gestational age babies is associated with significant perinatal morbidity suggests that obstetric practice should take into consideration this group of babies. Perhaps one way in which Danielian and co-workers can overcome the criticisms of Gardosi (1993) would be to evaluate perinatal morbidity in fetuses who have been assessed by serial ultrasound scans, thereby obviating the use of birthweight and birthweight charts altogether? T. C. Chang