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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 4, July/August 2021
AFRICA
229
intra-uterine contraceptive device for contraception, which was
removed due to abnormal bleeding, and no further contraception
was offered to the patient. She was discussed in a multi-
disciplinary team (MDT) involving cardiothoracic surgery/
cardiology/maternal–foetal medicine/high-risk obstetrics.
The patient elected to have a valve redo and a 25-mm ON-X
valvewas inserted. The patient recommenced oral anticoagulation
after a period of intravenous heparin post operatively and the
foetal heart was confirmed. She had an uneventful vaginal
delivery of a 3-kg female neonate with good apgars.
Patient 2
A 20-year-old P0G1 presented at 21 weeks’ gestation to her local
hospital with a history of mitral valve prosthesis at age six years.
She had defaulted on follow up at cardiology since 2017 and
had stopped taking warfarin at least eight months previously.
Screening of her valves confirmed that one leaflet was stuck.
She was counselled in a MDT about valve redo surgery and the
complications to her herself and the foetus.
At surgery, a thrombus and pannus were noted, which
were impeding the valve leaflet movement. Her valve was
replaced with a 25-mm ON-X prosthesis. She had an uneventful
postoperative course and the foetal heart was confirmed on
ultrasound pre- and post surgery. She went into spontaneous
labour and delivered a 2.75-kg female with good apgars.
Patient 3
A 26-year-old primigravida was referred in active labour with
hypertension and cardiac failure. Her warfarin was stopped by
her local clinic mid-second trimester and the patient was not
referred for tertiary care. The patient rapidly progressed and
delivered vaginally. Valve screening showed suspicion of a stuck
valve. She was assessed by the MDT and counselled for an
emergent redo valve surgery.
The intra-operative findings included the mitral valve leaflet
stuck in an open position with thrombus formation around the
valve hinge. The valve was replaced with a 25-mmON-X prosthetic
valve. She recovered well post operation and was discharged to her
referral centre for follow up, with counselling on contraception,
compliance with anticoagulation therapy and pre-pregnancy
assessment should she contemplate future pregnancies.
Patient 4
A 24-year-old patient, P1G2, presented with an anembryonic
pregnancy. She had had a previous stillbirth at 28 weeks’
gestation, most likely due to warfarin exposure. Screening of her
valves revealed a stuck mitral valve leaflet.
The patient agreed to a suction curettage and valve-redo
surgery. On day seven post evacuation, she had her mitral valve
explanted and replaced with a 27/29-mm ON-X mechanical
prosthesis as the mitral valve prosthesis was thrombosed with a
large clot on both the left atrial and ventricle sides. The aortic
valve was inspected and found to be incompetent and a 21-mm
ON-X mechanical aortic prosthesis was implanted. The patient
had an uneventful recovery and was counselled on compliance,
contraception and booking at the pre-pregnancy clinic when
planning her next pregnancy.
Patient 5
A 19-year-old primigravida in her first pregnancy presented
to cardiology with a stuck mitral valve and poor compliance
with warfarin. She was counselled and admitted for intravenous
heparin and review by cardiothoracic surgery for possible mitral
valve-redo surgery.
At surgery, the mitral valve leaflet was seen to be thrombosed
at the hinge. She had her mitral valve prosthesis replaced with a
27/29-mm ON-X prosthesis and her native aortic valve replaced
with a 21-mm ON-X mechanical valve due to severe aortic valve
disease. She made an uneventful postoperative recovery.
The high-risk obstetrics unit was consulted immediately post
operation as there was now a suspicion that she was pregnant.
Subsequent ultrasound assessment revealed an 18-week intra-
uterine gestation with an absent foetal heart pulsation. She
was counselled and had a termination of pregnancy with
misoprostol. The patient was counselled on contraception and
the importance of a pre-pregnancy planning for the future. She
was returned to the care of the cardiothoracic team.
Patient 6
A 27-year-old patient, P2G3, was referred at 29 weeks’ gestation.
She had a history of poor compliance. Although asymptomatic,
screening revealed a stuck mitral valve leaflet. She was extensively
counselled by a MDT and consented to valve-redo surgery.
The patient had her mitral valve prosthesis redone with
the foetus
in utero
. At surgery the leaflet was noted to be
thrombosed and the valve was replaced with a 27/29-mm ON-X
mechanical prosthetic valve. The patient did not consent to foetal
monitoring during surgery and an intra-uterine foetal death was
noted post procedure. She underwent induction while still on
intravenous heparin and delivered a 1.2-kg stillbirth vaginally.
She was bridged onto oral anticoagulation and discharged via
the cardiothoracic ward on optimal oral anticoagulation and
contraception.
Discussion
The cases outlined above reinforce the areas of concern in the
management of pregnant women with cardiac prosthetic valves.
Maternal mortality as a result of valve thrombosis ranges
between two and 15%, even on heparin therapy.
8
Pregnant
women are at increased risk for valve thrombosis, which may be
exacerbated by the physiological changes of pregnancy.
8
Pregnancy is a hypercoagulable state due to the increase in
factors VII, VIII and X.
7
The formation of a thrombus or pannus
at the valve impacts on its functionality, leading to stenosis or
regurgitation.
10
Management of patients with thromboses is
complex due to the risk of perinatal morbidity and mortality.
Poor compliance and follow up contributed significantly to
the presentation of the above patients. Compliance failure
is a well-known problem to all healthcare workers in our
country and reasons include lack of insight into the need for
anticoagulation, poor follow up, the reluctance or failure of
medical professionals outside of obstetrics and gynaecology to
actively advocate contraceptive use in women of reproductive
age, lack of resources and knowledge regarding the management
of anticoagulation in pregnancy, as well as financial constraints
on the part of the patient.