A baby may be small for a variety of reasons, but there are certain overt maternal and fetal factors which may lead to, or are associated with, a poor fetal growth rate. Pre-eminent amongst the maternal factors is severe pre-eclampsia and in women with this disease the smallness of the baby is almost certainly due to the inadequacy of the uteroplacental circulation. Other maternal factors of importance are cigarette smoking, drug abuse and certain infections such as malaria. The most obvious fetal factors associated with a low birth weight are congenital malformations and chromosomal abnormalities, and there the failure of the fetus to achieve a normal weight is clearly an expression of a generalised disorder of growth and is unrelated to the adequacy or otherwise of the placenta. If cases such as these are removed from consideration, there remains an important residue of unduly small infants who are delivered after an apparently uncomplicated pregnancy, are free from congenital malformations and have a normal karotype; it is this group which is considered here.

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”.

Obstetric cholestasis (OC) is associated with significant perinatal mortality and maternal morbidity. Fetal outcome may be improved with increased antenatal surveillance and timely intervention. Frequently attributed to the Scandinavian authors Alvar Svanborg and Leif Thorling, the first case report was by Ahlfeld in 1883 who elegantly described recurrent jaundice in a pregnant patient that remitted with delivery. During the 1950's various terminologies originated describing some of the characteristic features of the disease: icterus gravidarum, cholestatic hepatosis and recurrent jaundice during pregnancy, all synonymous with ‘obstetric cholestasis.’ Ahlfeld's original patient did not complain of itching but over the recent years pruritis has become the commonest manifestation. Obstetric cholestasis is the most common disorder of liver function unique to pregnancy and second only to acute viral hepatitis as a cause of jaundice in the third trimester.

At the close of this century of immense technological advance there is still debate about how best to determine when confinement is due and whether widely available technology for this should be used for all pregnant women or not. The expected date of delivery (EDD) is a central point in antenatal care. Without accurate knowledge of gestational length the evaluation of fetal wellbeing and fetal growth, as well as the timing of delivery, is bound to be difficult. No one who remembers the uncertainities surrounding gestational age assignment in the time before the advent of modern ultrasound wishes a return to those times, anymore than it is unthinkable that the telephone, televison, microwave owens, fridges, calculators or computers can be dispensed with from our lives. No one would start a flight today without using the necessary electronic devices to enable safe flying, although this may have been done fifty years ago. It may then seem strange that ultrasonic measurements of the fetus, which enable gestational length to be assessed with good accuracy, should not be universally accepted. The last menstrual period (LMP) is still widely preferred for assigning gestational age, even where there is free access to modern ultrasound.

During pregnancy there are profound metabolic, endocrine and vascular changes which are tolerated for a short period of time. As the skin represents the largest organ of the body, these changes are also reflected in the appearance of the skin both by the improvement or exacerbation of pre-existing skin disease and by the development of new dermatoses. The specific dermatoses of pregnancy are a group of disorders which only occur in the pregnant state.

This review will discuss the physiological effects of pregnancy on the appearance and function of normal skin, and other cutaneous diseases affected by pregnancy (including intrahepatic cholestasis). The latter part of the review will discuss important aspects of the specific dermatoses of pregnancy.

Preeclampsia is a common disorder of human pregnancy and is a leading cause of maternal and neonatal death world-wide. The disease is polymorphic, with involvement of the placenta, maternal vasculature, central nervous system, coagulation cascade, liver and kidney. Preeclampsia is also associated with an increased incidence of fetal intrauterine growth restriction (IUGR). Often, the only treatment option is delivery with consequent fetal prematurity. The clinical markers of this disorder include hypertension and proteinuria, which reverse after delivery. Hypertension is a result of the disease and is rarely of pathogenic importance. When accompanied by convulsions the syndrome is termed eclampsia (derived from the Greek eklampsis or “sudden flashing”). A primary clinical goal is to prevent progression to this deadly complication. The incidence of preeclampsia is between 5 and 10% of pregnancies and there is no evidence that this has changed appreciably during the last century. Despite the lack of progress from a practical standpoint, new insights into the aetiology and pathogenesis of preeclampsia continue to arise.

For several decades, visual analysis of the antepartum fetal heart rate tracing has been a primary mode of fetal surveillance despite lack of proof from randomized trials that its use leads to a reduction in perinatal mortality in high risk pregnancies. A meta-analysis of these trials offered the same conclusion. The trials were performed in the early 1980's with fetal monitors with poor signal to noise ratios and poorer testing schemes in comparison to today. Therefore the results may no longer be pertinent, however, it is unlikely that these trials will be repeated because of present medico-legal constraints. Nonetheless, the use of non-stress testing alone is an accepted mode of fetal surveillance because of associated low fetal death rates within 1 week of a normal test; 1.9 to 3.2/1000 patients tested. The expense associated with this low fetal death rate is a low positive predictive value of 25% to 50%. Interrelated with this inefficiency, is the considerable inter- and intra-observer variation in the interpretation of antepartum fetal heart rate tracings. Variation in the interpretation of antepartum fetal heart rate tracings continues to exist despite the increase in experience and knowledge of fetal heart rate monitoring and improvement in fetal heart rate monitors. The end result is a form of fetal surveillance that is of questionable value and inefficient, requiring frequent back up testing to clarify fetal condition.

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.

Genital herpes infection remains a difficult problem to manage during pregnancy. The natural history of the infection during pregnancy is not well understood and potential management strategies remain unevaluated. For example the risk of mother-to-child transmission in women with recurrent genital herpes lesions at the time of vaginal delivery is still unknown. We do not know whether delivery by caesarean section decreases this risk and yet it is the most widely used intervention in this situation. We are only just beginning to understand the epidemiology of asymptomatic infection and the risk that asymptomatic viral shedding may pose to the newborn. In addition, new methods of diagnosis and new strategies for management are regularly being proposed with little formal evaluation of their effectiveness in the clinical setting.

This article aims to review current knowledge applicable to the clinical situation and suggest how our knowledge and management of this problem may be improved in the future.

Attwood traces the earliest possible description of a case of amniotic fluid embolism (AFE) to 1825. The next case was described by Meyer some 101 years later. Not until 1941 was this obstetric catastrophe recognised as constituting a true syndrome with its own clinical and pathological characteristics. Any combination of sudden and profound shock, dyspnoea, cyanosis, apprehension, seizures, and the failure of rapid blood coagulation may herald the clinical onset of an AFE. Liban was the first to report the detection of squamous cells throughout the systemic circulation, an observation which was not explained at the time. Many have commented upon the ominous fetal heart pattern that almost invariably accompanies AFE if the fetus is in-utero at the time of the embolus.

In medicine, in general and fetal medicine in particular, the conceptual development and emerging application of a new diagnostic modality is fuelled firstly by a general recognition of the increasing relative importance of a particular clinical problem and then by critical examination of the body of scientific observation, often disparate in origin, that provides the key insights into the pathophysiology, manifestation and natural history of the disease process. So it is with the evolution of the fetal biophysical profile score. In general terms, until the 1950's the major goal of obstetric care was the prevention of maternal mortality and morbidity. As the result of a host of clinical advances including improved anaesthesia and surgical techniques and availability of blood and blood products, antibiotics and specific other drugs (oxytocin, anticonvulsants, antihypertensives, insulin etc.) maternal mortality declined to the low rates of the present day. Consequently, the focus of obstetric care shifted to the recognition and prevention of death or damage affecting the other patient in the obstetric dyad: the fetus. The first methods for evaluation of antepartum fetal health care were based on measurements of biochemical variables in the maternal compartment (e.g. oestriol, placental lactogen, alkaline phosphatase and oxytocinase).

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 spectrum of abdominal wall defects includes exomphalos (omphalocoele), gastroschisis, and bladder and cloacal exstrophy. These congenital anomalies are readily recognised on a prenatal ultrasound scan. A raised maternal serum alpha-fetoprotein (MSAFP) should also prompt an ultrasound examination looking specifically for these anomalies, as well as neural tube defects. The influence of prenatal diagnosis on the peri- and postnatal management and outcome is still the subject of debate. Most published work relies on patient numbers too small to be of use statistically. Attempting to draw objective conclusions is made difficult because published series come from units with differing facilities and levels of expertise in the many professional groups involved in the management of these often complex anomalies.

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.