CHAPTER 9 This chapter addresses the recognition and management of emergencies in the later stages of pregnancy, including the first and second stages of labour – up to and including delivery of the baby. Hypertension from all causes is the commonest medical problem in pregnancy and affects between 10% and 15% of all pregnancies. Hypertensive conditions include PIH, pre‐existing hypertension (e.g. ‘essential’ hypertension), pre‐eclampsia and eclampsia. The two conditions of HELLP syndrome and AFLP are felt to be part of the spectrum of disease that includes pre‐eclampsia and eclampsia. Women may enter pregnancy with pre‐existing hypertension. If hypertension is detected before 20 weeks, this is likely to reflect pre‐existing hypertension. Hypertension in a young person may only be detected for the first time in early pregnancy. At some point, this will require formal investigation to exclude an underlying cause (e.g. renal or cardiac disease, or Cushing’s syndrome). However, most will not have a defined cause and fall under the category of mild ‘essential’ hypertension. These women are at increased risk of developing superimposed pre‐eclampsia and fetal growth restriction. The risk is almost 50% if there is severe hypertension in early pregnancy (diastolic BP >110 mmHg, systolic BP >160 mmHg). Again, such patients require close monitoring in order to detect complications, and in particular the development of pre‐eclampsia or growth restriction. Pregnancy‐induced hypertension is a significant rise in blood pressure occurring after 20 weeks in the absence of proteinuria or other features of pre‐eclampsia. Women with uncomplicated PIH require close monitoring in the antenatal period to pick up those who are going to develop pre‐eclampsia. If hypertension is uncomplicated by pre‐eclampsia, the maternal and fetal outcomes are good. Pre‐eclampsia is hypertension associated with proteinuria developing after 20 weeks’ gestation. It can occur as early as 20 weeks but more commonly occurs in the third trimester. It is more common in first pregnancies where one in ten women will develop pre‐eclampsia. Severe pre‐eclampsia is pre‐eclampsia with severe hypertension (>160/110 mmHg) and/or with symptoms and/or haematological impairment. The incidence of severe pre‐eclampsia is approximately 1% of all pregnancies. The underlying pathophysiology is not fully understood. However, it is known that the placenta plays an important role, such that the normal physiological changes that occur in the vessels of the uterus do not occur. This leads to poor perfusion of the placenta, resulting in a fetus which is growth restricted. In the 2013–15 report, pre‐eclampsia accounted for 3 of the 88 maternal deaths related to direct pregnancy causes (MBRRACE‐UK, 2017). In previous reports, the care of 70% of women who died was deemed to be substandard, and these deaths may have been avoided with better care (CMACE, 2011). Women with mild to moderate pre‐eclampsia are asymptomatic and the disease is usually diagnosed at routine antenatal visits. This is often managed on an outpatient basis initially, with regular review on the obstetric day unit. However, it may require admission to hospital and early delivery if the disease progresses. When measuring BP, the woman should be semi‐recumbent and an appropriately sized cuff should be used. In women with a larger arm, using a normal‐sized cuff may result in falsely high BP readings. It is important to record both systolic and diastolic pressures. The latter should be assessed using Korotkoff V (that is, sound disappearance). Korotkoff IV (that is, ‘muffling’) should only be used if heart sounds do not disappear as pressure readings fall to zero (see Chapter 5). Severe pre‐eclampsia may present in a patient with known mild pre‐eclampsia or may present with little prior warning. The BP is significantly raised (<160/110 mmHg) with proteinuria and/or more of the following symptoms and signs: Severe pre‐eclampsia is a ‘multi‐organ’ disease – although hypertension is a cardinal feature, other complications include: One of the ‘top ten recommendations’ in the CEMACH report highlighted the importance of aggressive treatment of high systolic BP (160 mmHg or more) in order to reduce the chance of maternal intracerebral bleeding and stroke (CEMACH, 2007b). Therefore, these obstetric patients require immediate admission to an appropriate obstetric unit. Pre‐hospital healthcare practitioners will not usually be involved with management of gestational hypertension or mild pre‐eclampsia. However, it is important that any pregnant woman should have their BP checked during assessment, even if they do not have suspicious symptoms. A new finding of a BP of 140/90 or higher requires review by a midwife or discussion with the local obstetric unit to decide if admission is necessary. The following recommendations relate to the management of women with severe pre‐eclampsia: Eclampsia is defined as tonic‐clonic, generalised ‘grand mal’ seizures, usually in association with signs or symptoms of pre‐eclampsia. It is one of the most dangerous complications of pregnancy, with a mortality rate of 2% in the UK. It occurs in 2.7:10 000 deliveries, usually beyond 24 weeks (Knight, 2007). Many patients will have had pre‐existing pre‐eclampsia (of mild, moderate or severe degree), but cases of eclampsia can present acutely with no prior warning. One‐third of cases present for the first time post‐delivery (usually in the first 48 hours). Although eclampsia is often preceded by severe pre‐eclampsia, in many cases the blood pressure will only be mildly elevated at presentation. The hypoxia caused during a grand mal seizure may lead to significant fetal compromise and even death. There is a risk of placental abruption and massive haemorrhage. Occasionally, there may be cortical blindness after an eclamptic fit. Fitting is usually self‐limiting, but may be prolonged and repeated. Other complications associated with eclampsia include renal failure, hepatic failure and DIC. The diagnosis is made through the presence or history of a tonic‐clonic fit after 20 weeks of pregnancy.
Emergencies in late pregnancy (from 20 weeks)
9.1 Hypertension in pregnancy
Pre‐existing hypertension
Definition
Pregnancy‐induced hypertension
Definition
Pre‐eclampsia
Definition
Risk factors for pre‐eclampsia and eclampsia
Diagnosis
Pre‐hospital management
Eclampsia
Definition
Diagnosis
Pre‐hospital management
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