Preterm birth represents the single largest cause of morbidity and mortality for newborns and a major cause of morbidity for pregnant women. It affects about 9% of births in high-income countries and an estimated 13% of births in low- and middle-income countries. Babies born preterm have high rates of early, late and post-neonatal mortality, and the risk of mortality increases as gestational age at birth decreases. Babies who survive have increased rates of disability.

Abnormal obstetric presentation is a challenge for obstetricians when either birth of a viable fetus (>23 weeks of gestation) is imminent or when counselling expecting women. Vertex or cephalic presentation is the most common situation and is associated with the lowest complication rate during birth. It is important to screen for abnormal obstetric presentation in order to prevent adverse outcomes and to prepare for the appropriate perinatal management.

Early pregnancy encompasses the first 12 weeks of pregnancy – also known as the first trimester. Vaginal bleeding (PV bleeding) in early pregnancy is one of the most common gynaecological presentations, affecting between 7 and 21% of all pregnancies [1].

There are several medical conditions, both maternal and fetal, which can influence the course of pregnancy or even the developing fetus. In the era of modern technology, high-tech ultrasound machines, sophisticated monitoring methods for both mother and her unborn child, it is not enough to deliver a live neonate. What is highly expected by all future parents is a delivery of a healthy baby with a very good prognosis. Therefore, it has to be acknowledged and appreciated that the role of an obstetrician or maternal-fetal specialist cannot be underestimated. General population screening of all pregnant women for medical conditions is essential to achieve this target; otherwise, it is not possible to select a group of pregnant women who require more detailed and watchful monitoring, special care or even targeted treatment. However, not only identification of pregnancies at increased risk for maternal or fetal morbidity and mortality is involved, but also health promotion, education and support for parents. Nowadays, it is possible to predict many severe medical conditions as early as in the first trimester of pregnancy. The awareness of a high-risk pregnancy may improve pregnancy outcomes or even be lifesaving for a mother, her fetus or even both.

The placenta is a unique organ of pregnancy that plays a key role in the normal development and normal growth of the fetus. It creates the intrauterine environment, which, as we know today, has a long-term impact on the health of the developing human being. Its ability to take over functions of the liver, lung, gastrointestinal tract, kidneys and endocrine organs illustrates its multi-organ function. The placenta has two main components – one is of maternal origin, one belongs to the fetus – and interaction between these two parts needs to be optimal for a successful pregnancy, controlling optimal exchange of nutrients, oxygen and removal of carbon dioxide. This chapter will give further insight into the structure, blood supply and metabolic transfer of the normal placenta and will present today’s concepts of its role in long-term health.

There are few epidemiological studies on cancer in pregnancy, as national registries usually do not combine data on both cancer diagnosis and obstetrics. Nationwide linkage studies estimated the incidence of pregnancy-associated cancer, defined as a cancer diagnosis during pregnancy or within 12 months from delivery, to be 1 in 1000–2000 pregnancies [1]. The difference in estimated incidence between studies is explained by the difference in denominator used (live births, births beyond 20 weeks or pregnancies). The distribution of the various cancer types diagnosed in pregnancy is similar to that in the non-pregnant premenopausal population. Gynaecological cancers are one of the most common oncological diagnoses during pregnancy, after breast cancer, melanoma and haematological cancers [2]. Figure 74.1 represents the distribution of patients with a diagnosis during pregnancy in the registry of the international network on Cancer, Infertility and Pregnancy (www.cancerinpregnancy.org). Melanoma is probably underrepresented in this registry, as these patients are mostly diagnosed in the early stage and often not referred to centres that participate in the registration study.

The female genitourinary system is mainly derived from the intermediate cell mass, which in turn is derived from the mesoderm following gastrulation. The pelvic girdle, however, is derived from the caudal mesoderm, which, as the name implies, is the mesoderm found caudal to the cloacal membrane. Upon folding, the caudal mesoderm folds ventrally at the point of the cloacal membrane, distal to the paraxial mesoderm and notochord, in such a way that the pelvic girdle wraps around the distal end of the trunk to fuse with the sacral somites and encase the developing female genitourinary system, and leads to the formation of the rump. Blastogenic defects involving the cloaca and caudal folding may also be associated with urogenital and possibly ano-rectal malformations, which can lead to reproductive problems [1].

Augmentation of labour is the process of stimulating the uterus to increase the frequency, duration and intensity of contractions after the onset of labour. Augmentation is used to treat delayed labour when uterine contractions are assessed to be insufficiently strong or inappropriately coordinated to effectively cause cervical dilation or effacement. Labour augmentation has traditionally been performed with the use of intravenous oxytocin infusion and/or artificial rupture of amniotic membranes. The procedure aims to shorten labour in order to prevent complications relating to undue prolongation and to avert caesarean section. It is central to the concept of active management of the first stage of labour, which was proposed about four decades ago as a strategy for expediting labour and reducing caesarean section rates [1].

Pharmaceutical agents have become an essential tool in the medical armamentarium. Pharmaceutical companies over the past century not only have developed more consistently effective agents that are used to manage acute-onset conditions, but also have improved the quality of life of those suffering from chronic progressive disease. The use of any medication must be tempered by its potential side effects. Thus, the clinician must assess the benefit-risk ratio between therapeutic efficacy and safety risks before resorting to any therapeutic intervention in any patient. The benefit-risk assessment (BRA) is made on the weight of randomized evidence obtained from formal clinical trials and observations collected from pharmacovigilance activities after the drug is put on the market [1]. In obstetric practice, the benefit-risk ratio assessment for a pharmaceutical agent must further consider the specific benefit-risk ratio assessment relevant to the developing fetus. The fetal risk assessment presented by a particular agent may not be immediately possible since adverse effects may not be specific and easily linked to the agent, or may present themselves later on in life.

Immunization is one of the most effective preventive health measures; it reduces the incidence and severity of vaccine-preventable infectious diseases, saving millions of people from illness, disability and death every year. According to the World Health Organization (WHO), safe and effective vaccines protecting against 26 different diseases are currently available, while another 24 vaccines are under development (Figure 66.1) [1, 2].

The aim of intrapartum fetal monitoring is to identify fetal hypoxia and intervene appropriately before permanent damage occurs, while concomitantly avoiding unnecessary operative deliveries. Therefore, such monitoring needs to identify fetuses whose physiological defence mechanisms are becoming compromised, so that healthcare professionals can act before an uncontrolled phase leading to injury occurs.

Preterm prelabour rupture of membranes (PPROM) is defined as rupture of the membranes before 37 weeks’ gestation. PPROM complicates only 2% of pregnancies but it is associated with 40% of preterm deliveries [1]. It is the single most common identifiable factor associated with preterm births. The latency period between rupture of membranes and labour tends to be inversely correlated with gestation, being longer with decreasing gestational age. The majority of pregnancies complicated by PPROM will deliver within a week of amniorrhexis.

Systemic lupus erythematosus (SLE) is a chronic multi-organ inflammatory disease which can involve any organ or system. It is an autoimmune condition with an overproduction of autoantibodies directed against various nuclear components and cell-surface antigens. The underlying cause of the condition is unknown, but it is likely multifactorial with genetic and environmental factors having a role. The incidence is higher in women than in men; some sources quote this as high as 9:1, and is even higher during the reproductive years [1, 2].

Postpartum haemorrhage (PPH) is the one of the leading causes of maternal morbidity and mortality worldwide, with the World Health Organization (WHO) estimating 140 000 maternal deaths every year due to PPH [1]. Between 1990 and 2015 there has been a decrease in the number of women dying in the perinatal period (all-cause mortality) with 385 death per 100 000 live births in 1990 decreasing to 216 per 100 000 live births; however, a significant gap in the mortality in developed and developing countries persists [2]. In 2015, the maternal mortality rate in low-income countries was 479 per 100 000 live births versus 13 per 100 000 births in high-income countries [2]. In the UK, PPH is the third most common direct cause of maternal death and was attributable for 0.78 deaths per 100 000 maternities between 2014 and 2016 [3]. Maternal death, however, can only be seen as the tip of the iceberg, with 492 cases of morbidities reported in Scotland during 2012 and many other unreported cases of morbidities such as post-traumatic stress syndrome [4].

Obstetric research is vital. It provides insights into normal physiological responses of the body, the impact of pathology on those responses and understanding about how to diagnose and treat disease.

Caesarean section is the most commonly performed obstetric operation. A woman’s first caesarean section is generally an easy operation. Obstetricians are the only surgeons who routinely operate on the same surgical scar, and a third or fourth caesarean section can be a very challenging operation indeed. There is no question that a caesarean section is a lifesaving operation, but in the modern world the expectation from the women we serve is that it will also be a safe one, with as few side effects as possible. It is hoped that some of the information in this chapter will help you to achieve that.