Introduction
In the United Kingdom (U.K.), although the overall maternal mortality
rate (MMR) has remained low1, significant racial
disparities within maternal outcomes have persisted. The most recent
Mothers and Babies: Reducing Risk through Audits and Confidential
Enquiries-U.K. (MBRRACE-U.K.) report revealed that Black women are four
times more likely to die than their White counterparts due to pregnancy
related complications.1 Black women are also more
likely to suffer from severe maternal morbidity, or so called
“near-miss” events even when potential confounding factors such as
socioeconomic and smoking status, and high Body Mass Index (BMI) are
accounted for.2
Amongst indirect causes of maternal mortality, cardiovascular disease
remains the most significant contributor.1Hypertensive disorders in pregnancy (HDP), which encompass gestational
hypertension, pre-eclampsia and pre-existing hypertension, are
classified as direct causes of maternal mortality, however it is
irrefutable that HDP in addition to the physiological changes of
pregnancy can considerably exacerbate pre-existing cardiovascular
disease leading to increased morbidity and mortality.3HDP complicate up to 10 percent of pregnancies4 and
having a diagnosis of HDP also increases the risk of developing
cardiovascular disease in later life.5 It is therefore
imperative that HDP is managed in an appropriate and timely manner.
In a non-pregnant patient, first line management of hypertension differs
based on ethnicity.6 In the U.K., NICE guidelines
recommend commencing Calcium Channel Blockers (CCB) initially for
treatment of raised blood pressure in patients of any age from Black
African and African Caribbean origin.7 The variance in
initial pharmacological management is because in Black patients with
hypertension, there is evidence to suggest that CCB monotherapy is more
effective at reducing blood pressure than Beta Blocker
monotherapy.8 Presently, the first line
pharmacological management of all pregnant women with hypertension and
pre-eclampsia in the U.K. is the non-specific alpha- and beta- blocker,
Labetalol.9 Although, there have been numerous
clinical trials investigating the management of hypertensive disorders
in pregnancy, there is a lack of knowledge regarding whether the race
based differences in first line anti-hypertensive management out with
pregnancy should extend to pregnant women.
Therefore, our primary objective was to address this gap in evidence by
undertaking a systematic review of all randomised control trials
investigating pharmacological management of HDP to assess whether CCBs
are the most effective anti-hypertensive agent in Black pregnant women.