Eclampsia is defined in the obstetrical literature as the occurrence of unexplained seizure during pregnancy in a woman with preeclampsia. In the Western world, the incidence of eclampsia is ~1 per 2000 to 1 per 3000 pregnancies, but the incidence is 10-fold higher in tertiary referral centers and undeveloped countries where there is poor prenatal care, and in multi-fetal gestations. Nearly 1 in 50 women with eclampsia die as do 1 in 14 of their offspring, and mortality rates are considerably higher in undeveloped countries. Eclampsia is also associated with significant life-threatening complications, including neurological events. Seizure acutely can cause stroke, haemorrhage, oedema and brain herniation and thus lead to epilepsy and cognitive impairment later in life.

Obesity is a growing problem in obstetric practice. A recent study from Glasgow (UK) showed that 50% of women of childbearing age are either overweight (Body Mass Index [BMI] = 24.9–29.9kg/m2) or obese with 18% starting pregnancy as obese. Obesity prevalence has doubled over a decade from the early 1990’s. In the US it is estimated that 30% of reproductive-age women have a BMI greater than 30 kg/m while 7% have a BMI > 40 kg/m2. A recent report from the UK found that 5% of women had a BMI >35 kg/m2, 2% > 40 kg/m2 and 0.2% >50 kg/m2 with an association not only with social deprivation, but also with a higher prevalence of pre-existing medical disorders such as diabetes and hypertension and medical complications of pregnancy such as preeclampsia. Obesity was also associated with increased rates of macrosomia, operative delivery and postpartum haemorrhage. These data highlight the fact that obesity is an increasing health concern particularly in young women of childbearing age. Obesity will expose them to significant pregnancy complications ranging from miscarriage and fetal abnormality through to operative delivery and thromboembolism. There are also challenges for the delivery of maternity care to meet the needs of these women. As obesity is associated with significant pregnancy complications it is important that women enter pregnancy with an optimum body weight. Many complications, such as fetal abnormality occur in the first trimester and so pre-pregnancy weight reduction is preferred. Further, there is insufficient evidence to recommend specific dietary and/or physical activity interventions to reduce weight or moderate weight gain during pregnancy.

Physiologic changes in maternal haemodynamics, hormones and autonomic properties contribute to arrhythmias in pregnancy. While arrhythmias most commonly occur in pregnant women with structural heart disease or those with a history of cardiac arrhythmias, they can also occur de novo in women with no documented cardiac disease.

Platelets are an essential component of the first step in the process of haemostasis, plugging defects in the endothelium and providing a surface for secondary haemostasis to occur, via the coagulation pathway. Platelet aggregation and activation cause granule release of von Willebrand factor, ADP and serotonin, which, in turn, results in recruitment of more platelets to form the platelet plug. This serves to stop the bleeding, and also to activate the coagulation pathway on the surface of the activated platelets, leading to a firm fibrin clot.