Background Image
Table of Contents Table of Contents
Previous Page  50 / 72 Next Page
Information
Show Menu
Previous Page 50 / 72 Next Page
Page Background

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 2, March/April 2016

104

AFRICA

Hypertensive disorders of pregnancy: what the physician

needs to know

John Anthony, Albertino Damasceno, Dike Ojjii

Abstract

Hypertension developing during pregnancy may be caused

by a variety of different pathophysiological mechanisms. The

occurrence of proteinuric hypertension during the second

half of pregnancy identifies a group of women whose hyper-

tensive disorder is most likely to be caused by the pregnancy

itself and for whom the risk of complications, including

maternal mortality, is highest. Physicians identifying patients

with hypertension in pregnancy need to discriminate between

pre-eclampsia and other forms of hypertensive disease.

Pre-eclamptic disease requires obstetric intervention before

it will resolve and it must be managed in a multidisciplinary

environment. The principles of diagnosis and management of

these different entities are outlined in this review.

Keywords:

hypertention disorders, pregnancy

Submitted 14/1/16, accepted 14/4/16

Cardiovasc J Afr

2016;

27

: 104–110

www.cvja.co.za

DOI: 10.5830/CVJA-2016-051

Hypertension during pregnancy is widespread, representing

the most common medical complication of pregnancy and

affecting 6–8% of gestations in the United States of America.

Two hospital-based studies in sub-Saharan Africa have put the

prevalence of this disorder at 11.5 and 26.5% of all deliveries,

respectively.

1,2

There are four categories of hypertension in

pregnancy, chronic hypertension, gestational hypertension,

pre-eclampsia, and pre-eclampsia superimposed on chronic

hypertension, as defined by the National High Blood Pressure

Education Program Working Group in Pregnancy.

Hypertension during pregnancy is not only common but

also associated with a risk of morbidity and mortality.

3,4

The

risk of adverse outcomes during pregnancy is largely but not

exclusively confined to those pregnant women diagnosed to

have pre-eclampsia.

4,5

The separation of hypertension during

pregnancy into pre-eclampsia or non-pre-eclamptic disease is a

foundational consideration when determining the likely course

of the disease, the necessary management and the probable

outcome.

3

Pre-eclampsia is uniquely manifest during pregnancy and is

associated with a pathophysiological phenotype that encompasses

placental disease, growth restriction of the foetus and the development

of severe but reversible hypertension during pregnancy.

4,6,7

Chronic

hypertension, regardless of the precise diagnosis, is not specifically

associated with placental vascular disease or severe intra-uterine

growth restriction and will not remit after delivery.

8

The necessary

level of surveillance, hospitalisation and the need for preterm delivery

rests upon the distinction between these hypertensive diagnoses.

9

In this review we discuss the different types of hypertension

during pregnancy, and the physician evaluation, including

physical examination and laboratory investigations of the

hypertensive pregnant patient.

Pre-eclampsia

Epidemiology

Pre-eclampsia affects one in 30 primigravid women and one in

60 women in their second or subsequent pregnancies.

10

Those

who have suffered from the condition before are more likely to

develop it in subsequent pregnancies (a one-in-seven risk) and

women with underlying co-morbidity are also more likely to

develop this complication of pregnancy. Specifically, women

with chronic hypertension have a 25% risk of developing

superimposed pre-eclampsia, and women with collagen vascular

disease are also more prone to develop pre-eclampsia.

8,9,11

There

is also a hereditary component, and obesity is strongly associated

with the risk of developing the condition.

12

Obstetric risk factors include an increasing risk of developing

pre-eclampsia related to multiple and even higher-order multiple

pregnancies. A large placenta, such as those seen in women with

trophoblastic disease or various kinds of foetal aneuploidy,

are also associated with an increased risk of developing

pre-eclampsia. Other risk factors that have been identified as

leading to an increased probability of pre-eclampsia developing

during pregnancy include antiphospholipid antibody syndrome,

chronic hypertension, chronic renal disease, a maternal age over

40 years, nulliparity, incidence of pre-eclampsia in a previous

pregnancy and pre-gestational diabetes.

The highest incidence of pre-eclampsia is among women

having their first baby, whereas the greater prevalence of the

disease is in multiparous pregnant women. The disease is

described as a condition of primigravidity but it is also, to some

extent, associated with primipaternity.

10

Clinical phenotype

Pre-eclampsia is a syndrome characterised by the development

of hypertension and proteinuria in the latter part of pregnancy,

which then remits after delivery.

3

Pre-eclampsia is unlikely to be

the cause of hypertension or proteinuria developing before the

20th week of pregnancy.

Division of Obstetrics and Gynaecology, Groote Schuur

Hospital, University of Cape Town, Cape Town, South Africa

John Anthony, MB, ChB, FCOG, MPhil,

john.anthony@uct.ac.za

Department of Cardiology, Faculty of Medicine, Eduardo

Mondlane University, Maputo, Mozambique

Albertino Damasceno, MD, PhD, FESC

Department of Cardiology, University of Abuja, Abuja, Nigeria

Dike Ojjii, MD, PhD, FESC