CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 4, May 2012
216
AFRICA
An audit of pregnant women with prosthetic heart
valves at a tertiary hospital in South Africa:
a five-year experience
B MAZIBUKO, H RAMNARAIN, J MOODLEY
Abstract
Background:
Cardiac disease in pregnancy is a common
problem in under-resourced countries and a significant cause
of maternal morbidity and mortality. A large proportion of
patients with cardiac disease have prosthetic mechanical
heart valve replacements, warranting prophylactic antico-
agulation.
Aim:
To evaluate obstetric outcomes in women with pros-
thetic heart valves in an under-resourced country.
Methods:
A retrospective chart review was performed of 61
pregnant patients with prosthetic valve prostheses referred to
our tertiary hospital over a five-year period.
Results:
Sixty-one (6%) of 1 021 pregnant women with a
diagnosis of cardiac disease had prosthetic heart valves.
Fifty-nine had mechanical valves and were on prophylactic
anticoagulation therapy, three had stopped their medication
prior to pregnancy and two had bioprosthetic valves. There
were forty-one (67%) live births, two (3%) early neonatal
deaths, 12 (20%) miscarriages and six (10%) stillbirths.
Maternal complications included mitral valve thrombosis
(
n
=
4), atrial fibrillation (
n
=
8), infective endocarditis (
n
=
6), caesarean section wound haematomas (
n
=
7), broad liga-
ment haematoma (
n
=
1) and warfarin embryopathy (
n
=
4).
Haemorrhagic complications occurred in five patients and
all five required blood transfusions.
Conclusion:
Prophylactic anticoagulation with warfarin in
patients with mechanical heart valve prostheses was associ-
ated with high rates of maternal and neonatal complica-
tions, including significant foetal wastage in the first and
early second trimesters of pregnancy. Health professionals
providing care for pregnant women with prosthetic heart
valves must consistently advise on family planning matters,
adherence to anticoagulation regimes and consider the use
of prophylactic anticoagulant regimens other than warfarin,
particularly during the first trimester of pregnancy.
Keywords:
prosthetic heart valves, anticoagulation, maternal
and foetal outcomes
Submitted 3/11/10, accepted 6/3/12
Cardiovasc J Afr
2012;
23
: 216–221
DOI: 10.5830/CVJA-2012-022
Women with mechanical prosthetic heart valves (MPHV)
are at greater risk of developing complications than those
with cardiac disease without MPHV.
1
The main reason is that
MPHV require lifelong anticoagulation to reduce the high risk
of associated thrombo-embolic complications.
1,2
In addition
pregnancy, being a hypercoaguable state, further increases the
risk of thrombo-embolic complications and results in a 35%
functional deterioration of MPHV.
2
It is therefore not surprising
that complications associated with cardiac valvular disease in
pregnancy carry with them significant mortality and morbidity,
particularly in under-resourced countries.
3-6
Prophylactic anticoagulation treatment options for patients
with MPHV in pregnancy include warfarin, unfractionated
heparin (UH) and low-molecular weight heparin (LMWH).
1,7
These agents are associated with increased maternal and foetal
complications, treatment failures, high financial costs and
potential teratogenic effects.
1-4,8
Warfarin usage in the first
trimester of pregnancy, for example is associated with high rates
of congenital malformations and foetal losses.
1-4
Therefore many
authors suggest that warfarin be replaced by heparin, at least in
the first trimester.
1,4-6
High rates of treatment failure and mortality with the use
of UH have also been reported.
6
Low-molecular weight or
fractionated heparin does not cross the placental barrier and is
not reported to have teratogenic potential. Its use for prophylactic
anticoagulation therapy may be preferred in pregnancy.
2,7
In
addition, LMWH has a longer half-life than UH. However, its
use in pregnancy is still controversial due to the lack of adequate
clinical trials.
1,8
The majority of pregnant patients with MPHV have been
managed at a single tertiary/quaternary facility in Durban by
a multidisciplinary team since 2003. It is therefore likely that
a single approach to prophylactic anticoagulation was used at
this facility. The opportunity was therefore taken to conduct
a retrospective chart review of management of patients with
MPHV in pregnancy.
Methods
This was a retrospective study of pregnant patients with MPHV,
referred to a tertiary facility for management over a five-year
period (January 2005 to December 2009). Ethical and hospital
permission were obtained from the appropriate authorities.
At every patient visit, relevant data were captured on a software
package (Medicom, Medicom Solutions, India). Baseline
data recorded included demographic obstetric information,
Department of Obstetrics and Gynaecology, Nelson R
Mandela School of Medicine, University of KwaZulu-Natal,
Durban, South Africa
B MAZIBUKO, MD
H RAMNARAIN, MD
Women’s Health and HIV Research Group, Nelson R
Mandela School of Medicine, University of KwaZulu-Natal,
Durban, South Africa
J MOODLEY, MD,
