Aspirin, acetylsalicylic acid, is the most frequently consumed drug in pregnancy, taken mostly without a prescription because of headache or a minor ailment. Numerous preparations containing acetylsalicylic acid are freely available over the counter under a variety of proprietary names, and in many cases pregnant women and their doctors may be unaware that aspirin is being taken.

Given the phylogenic antiquity of the renin angiotensin system (RAS) and the high degree of renin gene sequence conservation between species, it is perhaps not surprising that the RAS should be central to cardiovascular homeostasis. Nor, given the common embryological origin of the kidneys and reproductive tracts, is it especially surprising that the system should be influenced by, and may itself influence, the state of pregnancy. In this review I shall attempt to give an outline of the workings of the system in normal and in hypertensive pregnancy. The RAS is now known to be involved in spheres far beyond the ‘simple’ control of sodium and water homeostasis, and hence of blood pressure. Its roles in reproduction and in fetal life in animals have been very recently reviewed; this review will therefore confine itself to human studies unless otherwise stated.

The techniques employed in the diagnosis of placenta praevia have altered radically since Guillemeau first described the condition in 1685, stating that ‘The surgeon must consider if it is the child or if it is the after-birth who presents first’. However, his description went unnoted, for Giffart in narrating a case of haemorrhage wrote in 1730: ‘I cannot receive as absolutely true the opinion of those authors, who say that the placenta is always attached to the fundus uteri, for in this case, as in many others, I have every reason to believe that it adhered on the internal orifice, or very near to it; and that, in dilating, the latter occasioned the separation of the after-birth, and as a consequence the haemorrhage.’

Spontaneous rupture of the membranes usually accompanies the onset of labour, but precedes it in 10% of cases. Management, however, is not clear-cut and various treatments offer both risks and benefits to mother and infant in terms of intervention and nonintervention. Policies have changed over the last decade, moving towards a more conservative approach against a background of improved social conditions and antenatal care. Despite a wealth of literature documenting these changes, randomized controlled trials and unbiased reviews make up only a small proportion of the total number of papers surveyed. To base conclusions about the study of the management of prelabour rupture of the membranes upon statistically valid results, it is necessary to conduct a multicentre trial.