The antiphospholipid (aPL) syndrome has been defined as the production of autoantibodies against negatively charged phospholipids or phospholipid-protein complexes, clinically associated with thrombocytopenia, thrombosis, or pregnancy loss. The syndrome is considered a disease of systemic thrombosis. The frequency of thrombosis, however, is very low, despite most patients having stable levels of circulating aPLs. Documented thrombosis occurs only in approximately 35% of the patients, and, if recurrent, the events are generally separated by years (Table 1). The most common complication, however, is disturbance of pregnancy. Patients with aPLs have an 80% to 90% pregnancy loss rate, half of which occur in the first trimester. The incidence of pregnancy loss, however, depends on the criteria upon which the patients were selected and whether pregnancy outcome is analyzed retrospectively or prospectively. In some studies the pregnancy loss rate may be as low as 50% to 75%. Even the few cases of successful pregnancy are at risk of intrauterine growth restriction (IUGR), placental abruption, prematurity, and early and severe pregnancy-induced hypertension (PIH). Therefore, the vast majority of pregnancies in the presence of aPLs result in miscarriage or are severely complicated, with indications that placental damage occurs by the first trimester. When pregnancies are evaluated in the first trimester by ultrasound, IUGR is observed commonly before the death of the fetus. The strong and relatively specific association with pregnancy complications suggests that the syndrome should be redefined as “a syndrome of pregnancy”.

Bacterial vaginosis (BV) is an important polymicrobial state of abnormal genital tract colonisation which is easy to diagnose and easy to treat but which is poorly understood and therefore ignored or neglected by clinicians. Despite this, or perhaps as a result, BV is increasingly being associated with adverse sequelae in the practice of both obstetrics and gynaecology.

Successful human pregnancy is associated with striking physiological changes. Plasma volume increases early in the first trimester, attaining maximal expansion near term, when the increment above non-pregnant values is about 1.5 L (50–60%), and is a contributory factor in maintaining organ perfusion in the presence of arteriolar and venous dilatation. Effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) increase to values 50–70% above non-pregnant levels by term. There are also gestational alterations in osmoregulation as well as in the renal handling of sodium, potassium and glucose, coincident with altered tubular function. Plasma volume expansion is significantly related to fetal growth and pregnancies complicated by intrauterine growth retardation and pre-eclampsia are associated with reduced plasma volume and impaired renal function. Elucidation of factors involved in volume homeostasis and renal function in pregnancy is therefore of clinical as well as physiological importance. Atrial natriuretic peptide (ANP) causes vasodilatation, natriuresis and inhibition of the renin-angiotensin system and is clearly an important factor in volume homeostasis and renal function.

The human immunodeficiency virus (HIV) is a retrovirus which causes immune suppression mainly through depletion and destruction of CD4 lymphocytes. This results in increased susceptibility to opportunistic infections which in turn leads to acquired immune deficiency syndrome (AIDS). Since HIV (HIV-1) was first identified in 1983, the infection has spread across the world and has developed into arguably the most important and far-reaching pandemic of this century. HIV infection can be acquired through sexual contact, blood or blood products (including contaminated injecting equipment) and vertically from mother to child. Heterosexual acquisition is the dominant route among women, although in some settings injecting drug use (IDU) can also be an important source. In 1985, HIV-2 was isolated in a study of Senegalese women and subsequently found to be prevalent in West Africa and in areas of emigration from West Africa. HIV-2 is less transmissable and pathogenic than HIV-1 and this review is restricted to HIV-1 infection.