The uterine cervix is a remarkable structure, which plays an essential role in pregnancy. During the development of the conceptus within the uterus, the cervix usually remains firmly closed to ensure that the developing fetus attains an appropriate degree of maturity to permit extra-uterine survival. On the other hand, it prepares for labour and birth, by undergoing a process of effacement, whereby the substance of the cervix shortens and thins out. During labour, it must be stretched and dilated to a sufficient diameter, usually about 10cm at term, to allow the successful passage of the fetus through the birth canal.

Polycystic ovary syndrome (PCOS) is a common hormonal disorder affecting around 5–8% of women of reproductive age. It has a variable clinical spectrum including hyperandrogenism, menstrual abnormalities, polycystic ovaries and metabolic features like diabetes mellitus, obesity and dyslipidaemia. The manifestation of PCOS and its impact especially on reproductive function and pregnancy are profoundly affected by associated features of obesity/raised body mass index and metabolic syndrome.

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.

There is an intimate relationship between the kidney and pregnancy. Renal plasma flow increases by 50–70% during a normal pregnancy and the glomerular filtration rate by about 50%.1 These changes commence in the first trimester and fall in the last trimester reaching normal levels within about four weeks postpartum. These physiological changes are accompanied by striking anatomical changes which consist of dilatation of the ureter, pelvis and calyces, together with an increase in renal parenchymal size. The dilatation i s more marked on the right and may appear in the first trimester. At term, 90% of pregnant women show this change.2

Preeclampsia (PE) is a multisystem disorder of human pregnancy, affecting about 6% of all pregnancies worldwide, and is one of the leading causes of maternal and infant morbidity and mortality. Despite decades of research into the pathogenesis of this complex disease, the underlying mechanisms remain unclear. As a result, the options for prevention and management of PE are limited. In recent years, there has been a growing body of evidence suggesting that folate deficiency is associated with PE, and folic acid supplementation may reduce the risk of developing PE in certain populations. Folate contributes to cell division and growth, and folate metabolism is involved in a large number of physiological and pathophysiological processes in human development. Sufficient supply of folate is therefore particularly important during pregnancy. Nevertheless, the exact mechanisms of folic acid deficiency increasing the risk of developing PE are still unclear. This article reviews what is understood about the aetiology of PE and the relationship between folate metabolism and PE so as to enhance further discussions on the subject.

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.

Group B streptococcus (GBS), or Streptococcus agalactiae, has been a continuing focus of debate in the paediatric and obstetric worlds. The organism has emerged as the leading cause of early-onset neonatal sepsis. With an average of 20% of mothers being carriers for the organism (range from 15–40%), the following questions remain to be answered:

1 How best to screen for GBS and which protocol to use?

2 How best to counsel patients who are GBS carriers?

3 What is the cost effectiveness of the screening protocols?

Schmorl is generally credited with being the first to report finding fetal cells in maternal blood. In 1893 he identified trophoblasts in the pulmonary circulation of women who had died of eclampsia. Years later, in 1969, Walnowska identified Y chromosomes in lymphocytes isolated from the blood of pregnant women carrying male fetuses and this was repeated by Herzenberg in 1979 in white blood cells recognised as fetal by their surface HLA-A2 expression. Other sporadic reports followed but not until the 1990's did investigation into harvesting fetal cells from maternal blood begin in earnest. The aim of this article is to review the progress made in isolating and analysing these cells for the purposes of prenatal diagnosis.

Toxoplasmosis is one of the commonest protozoal infections in man. The causative organism, Toxoplasma gondi has been estimated to have infected in the region of 25–50% of the world's population with evidence of serological infection ranging from 2 to 90% depending on the geographical area. The infection is usually harmless and subclinical, the primary infection being rarely diagnosed. However, it can lead to life threatening disease in the immunocompromised patient and a primary infection in pregnancy can have severe sequelae in the fetus.

Umbilical cord prolapse is the descent of the umbilical cord through the cervix alongside (occult) or past (overt) the presenting part in the presence of ruptured membranes. Cord prolapse is a rare obstetric complication, usually requiring immediate delivery of the fetus to reduce neonatal morbidity and mortality. Therefore staff caring for women in labour should train regularly to manage it appropriately, because team training has been demonstrated to improve outcomes.

Deoxyribonucleic acid (DNA) is composed of a deoxyribose backbone, the three position (3') of each deoxyribose being linked to the five position (5') of the next by a phosphodiester bond. At the two position each deoxyribose is linked to one of four nucleic acids; the purines adenine or guanine or the pyrimadines thymine or cytosine. Each DNA molecule is made up of two such strands in a double helix with the nucleic acid bases on the inside. The bases pair by hydrogen bonding, adenine (A) with thymine (T) and cytosine (C) with guanine (G). Deoxyribonucleic acid is replicated by separation of the two strands and synthesis by DNA polymerases of new complementary strands. With one notable exception, the reverse transcriptase produced by viruses, DNA polymerases always add new bases at the 3' end of the molecule. Ribonucleic acid (RNA) has a structure similar to that of DNA but is always single stranded. The backbone consists of ribose, and uracil is used in place of thymine.

Congenital diaphragmatic hernia (CDH) is a simple anatomical defect. The reported incidence is between 1:2000 and 1:5000 live births, with the majority affecting the left side. A defect in the diaphragm allows abdominal viscera to herniate into and stay within the thoracic cavity during crucial stages of lung development. This results in pulmonary hypoplasia, a reduction in pulmonary vascular branching and an alteration in the surfactant system.

The first attempt to visualise the fetus with a panendoscope was performed in 1954. Embryoscopy and fetoscopy were developed in the 1970's. They were introduced as a diagnostic tool to visualise external malformations of the fetus in the first, second and third trimesters of pregnancy as well as to obtain fetal tissue for diagnostic purposes and perform fetal intravascular transfusion.

Diagnostic fetoscopy during the second and third trimester was abandoned in the late 80's due to the invasive nature of the technique and the development of high resolution ultrasound imaging. Percutaneous access to fetal blood and tissue sampling under continuous ultrasound guidance also became possible in the late eighties. Recently there has been renewed interest in embryo-fetoscopy due to the increasing use of ultrasound in the first trimester together with the development of new equipment, especially miniature fiberscopes. These have improved image resolution while being less invasive. Anomalies suspected in the first trimester often call for a rapid and complete fetal evaluation and microendoscopy allows for a sono-endoscopic assessment of fetal anatomy. This may help a couple to decide whether to carry on with the pregnancy or to opt for early termination of pregnancy (TOP). More recently, embryoscopy and fetoscopy have been used to operate on the placenta and membranes and also on the fetus itself.

Behaviour originally depends on precise and specific interconnections between nerve cells. The nervous system itself develops in a series of appropriately timed steps with a temporal sequence characteristic of each neural structure.

Artificial reproductive technology (ART) was first introduced to clinical practice in the late 1970s1 and has subsequently resulted in approximately 5 million births worldwide2 . Globally, the rates of assisted conceptions continue to rise3 . In 2011, approximately 1.5% of all pregnancies in the US were conceived using ART4 . Since its introduction, much interest has been generated regarding the effects of ART on the developing fetus and potential adverse impacts on the health of the mother. In particular, early studies suggested an increase in fetal genetic and structural anomalies, and a high risk of perinatal complications. As experience with pregnancies conceived using ART has increased worldwide and more data regarding the outcomes of ART-conceived pregnancies have been reported, many of the initial worries have been shown to be unfounded. However, concern still exists regarding whether any adverse fetal and maternal outcomes result from the use of this technology. Many studies have reported higher risks of fetal complications following the use of ART including an increase in perinatal mortality, even in singleton pregnancies5,6 . However, interpretation of these data are far from simple and it is important to consider that observations of higher rates of complications do not equate to a causal relationship between adverse pregnancy outcomes and the use of ART7 . There are multiple confounding factors that may account for these associations, many of which are difficult to control for in large-scale studies.

Although three-dimensional ultrasound (3DUS) was already being used in the early 1980's and the first commercially available three-dimensional scanner was presented in 1989 in Paris at the International Radiology Congress, it has only been in the recent decade that the technology has found its way into clinical applications. This rapid development is mainly due to the equally rapid development of computer processor technology, essential for three-dimensional ultrasound. Originally used as a tool for creating a surface mode showing the face of the fetus and gender abnormalities, its application has become much broader nowadays. The technique is now becoming ever more important in obstetrics and gynecology, but also in many other fields such as cardiology, surgical applications and urology. Three-dimensional ultrasound is an easy, quick and cheap imaging technique without any known adverse effects on the mother or developing fetus as has been stated by the American Institute of Ultrasound in Medicine (AIUM). In addition, it has been reported by numerous authors to be very accurate in assessing volumes. Recently, it has been suggested that both two- and three-dimensional ultrasound, especially in the 1st and 2nd trimester, are of positive influence in initiating the bonding between mother and infant.

In this review, we are concerned primarily with pyrexia (hyperthermia; increased maternal temperature in labour) as hypothermia is rare and usually iatrogenic (as in hypothermia for cardiac bypass surgery). We start by reviewing the factors determining maternal temperature, and how it can be measured. We move on to the effects of the commonest cause of maternal pyrexia in labour in modern obstetric practice in developed countries, epidural anaesthesia. We then discuss the most feared cause of maternal pyrexia in labour, chorioamnionitis.

The mammalian uterus is composed of a preponderance of small smooth muscle cells usually aligned in two layers. The number of muscle cells in the human uterus at term is estimated at 200 billion, each minute fusiform cell measuring about 5–10μm in diameter and about 200μm in length. The main function of the uterus is to harbour the developing fetus during pregnancy and then to contract vigorously during labour to expel the products of conception. In order for the uterus to contract rhythmically and forcefully, a mechanism must exist to allow interaction between muscle cells in order to achieve synchronous activity. Phasic or cyclical patterns of contractile activity of the uterus cannot be accounted for by stimulation or inhibition from the nervous or endocrine systems. Since myometrial cells are dependent upon action potentials for their contractile processes, some system must be present between the muscle cells for the propagation of action potentials between them. The observation that gap junctions occur in large numbers between myometrial cells during parturition is thought to be significant in this regard and they are considered to play an essential role in parturition and in the control and co-ordination of uterine contractility. In this brief review, we will discuss the role of gap junctions in the modulation of myometrial contractility and the mechanisms that regulate their synthesis and permeability.

Fetal reactivity to acoustic stimulation is a long-recognized phenomenon. Obstetrical interest in this phenomenon is usually considered to have begun with peiper’s report in 1925 of marked fetal movements following a pulsed, loud sound. Occasional attention to the subject was given in the subsequent five decades. Read and Miller are often credited with writing the first comprehensive clinical study of the usefulness of acoustic stimulation in evaluating fetal health. A clear finding in this study was the correlation between an abnormal contraction stress test and faliure of the fetus to respond to stimulation.