Heart disease and pregnancy.

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(Hellenic Journal of Cardiology) HJC ñ 275
Hellenic J Cardiol 47: 275-291, 2006
R
with congenital heart disease to survive
to adulthood. Half of these patients are
women, the majority of them of childbear-
ing age. Most interventions, however are
not curative, about half of the women with
congenital heart disease face the prospect
of further surgery, arrhythmia, heart fail-
ure, and–if managed inappropriately–pre-
mature death. The additional burden of
pregnancy represents a new challenge for
this growing number of patients with heart
disease.1
The number of women of childbearing
age with coronary artery disease is also ex-
pected to grow, because of both the ad-
vanced maternal age and fertility, and the
adoption of the western style of life, which
leads to a higher incidence of risk factors
for coronary atherosclerosis.2
In the past few decades, rheumatic
fever has decreased drastically in devel-
oped countries. Nevertheless, rheumatic
fever remains problematic in the develop-
ing countries. Immigrants represent an ad-
ditional population that may be at high risk,
because of social reasons or because of
lack of screening for congenital heart dis-
ease in their countries of origin.3
ecent advances in paediatric car-
diology and cardiac surgery have
enabled more than 85% of patients
Physiological changes during pregnancy,
delivery and the post-partum
The main physiological changes during
pregnancy are an increase in blood vol-
ume, heart rate and cardiac output and a
decrease in peripheral vascular resistance
(Figure 1).4
ñ The increase in blood volume (30-50%)
represents an adaptation process induced
by the increased metabolic demand of
the foetus. This increase starts as early as
the sixth week of pregnancy; the levels
peak by the 20th to 24th weeks of preg-
nancy, and then are sustained until term
or decrease. The underlying mechanism
is presumably hormonal, but the exact se-
quence of events remains unclear.
ñ Cardiac output increases in parallel with
the increase in blood volume (30-50%).
The rise of cardiac output in pregnancy is
disproportionately greater than the in-
crease in heart rate and is therefore at-
tributable to an augmentation of stroke
volume. As pregnancy advances, heart
rate increases, approximately by 10 to 20
beats per minute, and becomes the more
predominant factor in increasing cardiac
output.5
– There is a remarkable fluctuation in
resting cardiac output with changes in
position; the compression of the inferi-
or vena cava by the enlarged gravid
uterus in the supine position results in
decreased venous return and a conco-
mitant significant decrease in cardiac
output.6
– Due to this hyperdynamic status, mur-
murs develop in nearly all women dur-
ing pregnancy; they are usually soft mid-
Heart Disease and Pregnancy
AIKATERINI CHAMAIDI, MICHAEL A. GATZOULIS
Adult Congenital Heart Centre and Centre for Pulmonary Hypertension, Royal Brompton Hospital and the
National Heart & Lung Institute, Imperial College, London, UK
Manuscript received:
July 30, 2006;
Accepted:
August 8, 2006.
Address:
Michael A. Gatzoulis
Adult Congenital Heart
Centre and Centre for
Pulmonary
Hypertension
Royal Bromptom
Hospital and the
National Heart & Lung
Institute, Imperial
College
Sydney Street
London SW3 6NP, UK
e-mail:
M.Gatzoulis@rbht.nhs.uk
Key words:
Pregnancy, pre-
pregnancy
counselling,
pregnancy-related
risk.
Review Article
Review Article

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systolic and their intensity may increase as cardiac
output increases. A continuous murmur due to in-
creased mammary blood flow may also be heard.
Diastolic murmurs can be physiologic during preg-
nancy. However, echocardiography is also warrant-
ed when a diastolic murmur is present.
– Among healthy pregnant woman, serial echocar-
diography usually demonstrates minor increases
in both ventricular diastolic dimensions, which re-
main within the normal range, with a slight de-
crease in left ventricular end-systolic diameter and
a minimal increase in the size of the left atrium.
Left ventricular contractility appears to be depress-
ed in pregnancy, but the ejection fraction is main-
tained because of the altered loading conditions.7
Increased circulating volumes result in increased
transvalvular flow velocities. Minor degrees of atri-
oventricular valve regurgitation are common and of
no clinical significance.8
ñ Aortic root diameter increases during pregnancy,
by about 2-3 mm.9
ñ The 30% fall in systemic vascular resistance is a fun-
damental physiological change during pregnancy.
– This afterload reduction is due to the high flow,
low resistance, maternal placental circulation.
– Pulmonary pressures remain normal during preg-
nancy, suggesting a similar decrease in pulmonary
vascular resistance to accommodate the increased
cardiac output.
Haemodynamics are altered substantially during
labour and delivery, secondary to anxiety, pain, and
uterine contractions.
ñ Uterine contractions result in a 50% acute increase
in both heart rate and blood volume as uterine blood
enters the circulating pool (300 to 400 ml of blood).
The magnitude of the increase in cardiac output
during contractions increases as labour progres-
ses.
ñ Both systolic and diastolic blood pressures increase
markedly during contractions because of compres-
sion of the abdominal aorta by the uterus, resulting
in an increase in peripheral vascular resistance. The
augmentation is greater during the second stage of
delivery.
ñ In spite of the external haemorrhage associated with
delivery, cardiac output is significantly higher one to
two hours post-partum prior to initiation of placenta
contractions. This 60% to 80% increase in cardiac
output occurs immediately after delivery, because of
the temporary increase in venous return due to relief
of caval compression and the additional blood shift-
ing from the contracting uterus into the systemic cir-
culation.
The cardiovascular adaptations associated with
pregnancy regress by approximately six weeks after
delivery. 10
Preconception counselling
Discussions about future pregnancies, family plan-
ning and contraception should begin in adolescence,
both to prevent accidental and possibly dangerous
pregnancies and to allow patients to plan their lives.11
Counselling should address how pregnancy may af-
fect not just the mother, but also the foetus. It should
ideally be provided in a joint clinic by an obstetrician
A. Chamaidi, M.A. Gatzoulis
276 ñ HJC (Hellenic Journal of Cardiology)
Figure 1. Cardiovascular changes during preg-
nancy. Changes of stroke volume and plasma
volume.

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with expertise in heart disease and a cardiologist with
expertise in women with congenital heart disease.
The information should include estimation of mater-
nal mortality as well morbidity–for example, the like-
lihood of pregnancy resulting in heart failure requir-
ing hospitalisation, exacerbation of arrhythmias, or long
term deterioration in ventricular function. Parental life
expectancy should also be discussed, as premature
death, disability, or the need for major surgery will ob-
viously affect a couple’s ability to care for their child.12
If pregnancy is planned adequately it will allow the
minimisation of maternal risk, if necessary, by catheter
or surgical intervention before conception. Any surgi-
cal intervention should take into account the poten-
tial effect on pregnancy; special consideration should
be given for women of reproductive potential to using
tissue valves for valve replacement.
The timing of pregnancy is of importance. For ex-
ample, for those with a systemic right ventricle or uni-
ventricular heart, pregnancy is likely to be tolerated
better when the patient is in her twenties rather than
her late thirties.
Careful planning also allows the estimation and
minimisation of foetal risk (see “The risk for the foe-
tus”).
Contraception
None of the contraceptive methods available provides
100% cover at zero risk for women with heart disease.
“Natural methods” and “barrier methods” have unac-
ceptably high failure rates and cannot be recommend-
ed for women in whom pregnancy carries a substan-
tial risk. Combined oral contraceptives should be
avoided in patients at risk of thromboembolism be-
cause of the thrombophilic properties of oestrogen.
Progesterone-only oral contraceptives (mini-pill)
do not increase the risk for thromboembolism and
have few serious side effects, but the failure rate is
higher than that of the combined pill. Depot injec-
tions of progestogen are an alternative to the mini
pill, especially for adolescents for whom compliance
is a concern.
An intrauterine device impregnated with progesto-
gen has been an important advance in contraception for
patients with a high risk for pregnancy-related compli-
cations and thromboembolism. Such devices are highly
effective and safe: they reduce menstrual bleeding and
carry a very low risk of infection and ectopic pregnancy.
Sterilisation should be considered for women in
whom pregnancy would carry a prohibitively high risk.
Termination of pregnancy
The risk of termination of pregnancy increases with
increasing gestational age and should be performed
as soon as the decision has been made, preferably in the
first trimester. Suction curettage under local anaesthe-
sia is the preferred method. Medical abortion with oral
antiprogesterones and vaginally administered prosta-
glandins is probably contraindicated because the hae-
modynamic effects are unpredictable, although limited
information exists regarding patients with heart dis-
ease.
The risk for the mother
Risk stratification is based on general knowledge of
physiological changes during pregnancy, on existing
knowledge of specific heart diseases, especially those
which carry high risk for mortality, and on recent pro-
spective clinical studies examining maternal and foetal
outcomes during pregnancy.
Conditions with markedly reduced cardiac out-
put, such as stenotic lesions on the left side, are not
well tolerated. The decrease in systemic vascular re-
sistance suggests that regurgitant lesions on the left
side and left to right shunts will be generally well toler-
ated. For the same reason, right to left shunts increase
risk, and conditions associated with cardiac cyanosis are
not well tolerated.
Pulmonary hypertension continues to carry a pro-
hibitive risk during pregnancy, with mortality rates
between 30% and 50%, and this needs to be commu-
nicated early to the patient and the family (see below:
“Pulmonary hypertension”).
In the largest prospective multi-centre study to
date (CARPREG) of women with pregnancy and heart
disease, the frequency and predictors of pregnancy-
related complications among Canadian women with
heart disease were examined.13,14There were 562
women during 617 pregnancies. The study included
all pregnant women with congenital or acquired car-
diac lesions, excluding those who had mitral valve
prolapse with less than moderate mitral regurgita-
tion and those with arrhythmias. A primary cardiac
event occurred in 80 completed pregnancies (13%);
half of them occurred in the prepartum period. The
most frequent cardiovascular complications were
heart failure and arrhythmias. Three deaths were re-
ported.
The risk factors for cardiovascular complications
are shown in ∆able 1. The estimated risk of a cardiac
Heart Disease and Pregnancy
(Hellenic Journal of Cardiology) HJC ñ 277

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event in pregnancies without risk factor was 5%, with
one risk factor 27%, and with two risk factors 75%.
Regarding patients with congenital heart disease in
particular, a recent publication described 90 pregnan-
cies in 53 women, with 19.4% of primary maternal car-
diac events; pulmonary oedema occurred in 16.7% and
sustained arrhythmias in 2.8%. There were no maternal
deaths. In addition to the previous risk factors reported
in the CARPREG study, right ventricular dysfunction
in patients with ventriculo-arterial concordance and/or
severe pulmonary regurgitation were independent risk
factors for cardiac events, but not for death.15
The risk for the foetus
The potential for congenital heart disease in the off-
spring must be considered before conception. Over-
all, the chance is 4%16compared with a background
of 0.8% for the general population.17
For lesions with autosomal dominant inheritance—
DiGeorge, Marfan syndrome, Noonan syndrome and
hypertrophic cardiomyopathy—the risk of recurrence
of heart disease can be as high as 50%. If the muta-
tion is known, prenatal diagnosis at 12 weeks of gesta-
tion can be made by corionic biopsy.
A foetal nuchal translucency measurement at 12-
13 weeks gestation is a useful first screening test (the
incidence of congenital heart disease is only 1/1000
with normal nuchal thickness). A specialist foetal car-
diac echo scan at 14-16 weeks gestation should be of-
fered to detect moderate to severe congenital heart
lesions, and this may need repeating at 20 weeks.
For women with cyanotic or stenotic lesions, rou-
tine ultrasound biometry of the foetus is warranted.
Close assessment of foetal growth is also advisable in
patients with systemic hypertension or taking beta-
blockers. Maternal drugs may need changing before
conception or once pregnancy is confirmed.
A. Chamaidi, M.A. Gatzoulis
278 ñ HJC (Hellenic Journal of Cardiology)
Table 1. Generic cardiac risk factors for adverse maternal out-
comes during pregnancy.
ñ Poor functional class before pregnancy (NHYA class >II).
ñ Impaired left ventricular function (ejection fraction <40%).
ñ Left heart obstruction, mitral valve area <2 cm2, aortic valve area
<1.5 cm2, left ventricular outflow tract peak blood pressure gradi-
ent measured by Doppler echocardiography >30 mmHg.
ñ Preconception history of adverse cardiac events such as sympto-
matic arrhythmia, stroke, transient ischaemic attack and pul-
monary oedema.
The estimated risk of a cardiac event in pregnancies without risk factor was
5%, with one risk factor 27%, and 75% if two risk factors were present.
Overall, there is a higher incidence of foetal and
neonatal adverse events, including intrauterine growth
restriction, premature birth, intracranial haemorrhage,
and foetal loss, in women with heart disease com-
pared with the general population. By far the most
common complication in the foetus is growth restric-
tion, particularly when the increase in cardiac output
is inadequate so that the flow to the placenta is re-
stricted. This is amplified by any other obstetric risk
factors.
In a prospective study that examined the inci-
dence of adverse neonatal outcomes in women with
heart disease compared to healthy women, the inci-
dence was 18% and 7% respectively (Table 2). In pa-
tients with heart disease without obstetric complica-
tions and without known risk factors for neonatal
complications the actual incidence of neonatal com-
plications was similar to that in healthy women.18
Management of pregnancy, delivery and the post-partum
The level of antenatal care and monitoring required
should be determined before pregnancy, or when this
is not possible as soon as pregnancy is confirmed. See
Table 3, which includes risk stratification of heart dis-
eases during pregnancy. As most general obstetricians
will see only few patients with moderate to severe
heart disease, referral to a specialist centre for coun-
selling is strongly advisable.
Low risk patients can continue with their antenatal
care locally, taking into account the specialist recom-
mendations.19Moderate to high-risk patients should be
cared for in a tertiary, multidisciplinary environment.
Women with significant valvular heart disease should be
evaluated periodically, including echocardiography
(every trimester and whenever there is a change in sym-
ptoms).
Careful planning for antenatal care and delivery are
clearly required. Some patients may benefit from hospi-
Table 2. Generic risk factors for adverse neonatal outcome.
ñ Poor functional class before pregnancy (NHYA class >II).
ñ Impaired left ventricular function (ejection fraction <40%).
ñ Left heart obstruction, mitral valve area <2 cm2, aortic valve
area <1.5 cm2,left ventricular outflow tract peak blood pressure
gradient measured by Doppler echocardiography >30 mmHg.
ñ Cyanosis.
ñ Anticoagulant therapy.
ñ Multiple gestation.
ñ Smoking.
ñ Maternal age less than 20 or more than 35.

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talisation during the third trimester for bed rest, close
monitoring and oxygen therapy of cyanotic patients.
Drugs used during pregnancy
Most commonly used cardiovascular drugs for pa-
tients with heart disease cross the placenta and expose
the foetus to their pharmacological effects.20Drug ef-
fects are influenced by intrinsic pharmacokinetic pro-
perties and by the complex physiological changes oc-
curring during pregnancy, requiring adjusting doses
through pregnancy.
Some drugs also enter breast milk and may affect
the neonate and infant that way. The benefits and risks
for mother and foetus have to be weighed carefully.
See Table 4, which shows the most common drugs used
in cardiology.21,22
Complications during pregnancy
Arrhythmias
Both ectopics and sustained arrhythmias become more
frequent during pregnancy. In general they are treated
in the same way as outside pregnancy but as conserva-
tively as possible, although prevention of arrhythmia
and avoidance of the need for anticoagulation are clear-
ly desirable.
Antiarrhythmic drugs in pregnancy should be ad-
ministered at the lowest effective dose and for the short-
est duration possible. Monotherapy is also preferable.23
Supraventricular tachycardias can be terminated by
vagal stimulation, or failing that, with intravenous ade-
nosine.24Beta blockers with beta-1 selectivity are the
first choice for prophylaxis of supra- or ventricular ta-
chycardia during pregnancy. Potentially life-threatening
ventricular tachyarrhythmias are much less common
and should be terminated by electrical cardioversion.
Electrical cardioversion is not contraindicated dur-
ing pregnancy and should be used for any sustained
tachycardia causing haemodynamic instability and thus
threatening foetal and maternal well-being. Foetal
heart rate must be monitored and maternal airways
should be protected.
Amiodarone may be used with caution as a sec-
ond line drug in cases resistant to other antiarrhyth-
mic agents. It leads to neonatal hypothyroidism.
The presence of an implantable cardioverter-defib-
rillator does not itself contraindicate future pregnan-
cies. In a series of 44 pregnancies of women with such a
device the incidence of appropriate discharges was no
greater during than outside pregnancy, with good out-
comes for the mother and the foetus.25
A pacemaker for the alleviation of symptomatic
bradycardia can be implanted if needed. Echo guid-
ance can minimise the effects of radiation.
Heart Disease and Pregnancy
(Hellenic Journal of Cardiology) HJC ñ 279
Table 3. Risk stratification of heart diseases during pregnancy.
High risk
Pulmonary hypertension (mortality 30-50%)
ñ Eisenmenger syndrome
ñ Primary pulmonary hypertension
Univentricular physiology with or without
Fontan with severe dysfunction
Severe aortic/mitral stenosis
Marfan syndrome with severe aortic root
dilatation
Acute myocardial infarction during preg-
nancy
Severe systemic ventricular dysfunction:
ñ Dilated cardiomyopathy
ñ Previous peripartum cardiomyopathy
ñ Right ventricular systemic ventricle with
severe dysfunction (corrected congeni-
tal transposition of the great arteries,
Mustard)
Moderate risk
Estimated risk of mortality or major com-
plications: 1- 5%
Cyanotic lesions without pulmonary hyper-
tension
Single ventricle physiology (with or without
Fontan) with good systemic ventricular func-
tion
Mechanical prosthesis
Not severe aortic/mitral valve stenosis
Severe pulmonary stenosis
Marfan syndrome without marked aortic
root dilatation
Unrepaired coarctation of the aorta
Low risk
Estimated risk of mortality or major com-
plications: >1ò and <1%
Left to right shunts
Functionally normal bicuspid aortic valve
Biological prosthesis without residual car-
diac dysfunction
Asymptomatic moderate to severe mitral
or aortic regurgitation without left ventri-
cular dysfunction
Moderate pulmonary stenosis
Repair of Tetralogy of Fallot without resid-
ual lesions such as severe pulmonary regur-
gitation
Other repaired lesions without residual car-
diac dysfunction