High blood pressure (hypertension) currently impacts over 1 billion people worldwide and has significantly increased among all age groups including women of child-bearing age. Pregnant women with chronic hypertension are at risk of experiencing severe complications, putting them and their unborn child at risk. Such health risks include growth, survival, and healthy kidney development of the baby while in the womb. Mother's themselves may be at risk of stroke. In fear of these complications it is considered important to treat hypertension during pregnancy. However, at the same time one has to be very careful with such medical treatments as many blood pressure medications may also be harmful for the unborn child. Unfortunately it is very hard to carry out standard clinical trials on pregnant women and therefore the relation between hypertension and hypertensive treatment options for childbearing women has not been studied as well as one would expect. This study will give us the possibility to look back and study the medications that the women were taking while pregnant and hopefully find patterns indicating which drug or drug classes may be least harmful to the child.
Research is needed to assess the use of antihypertensive medication among adult females of child bearing age, under real world circumstances. Earlier studies have been unable to stratify anti-hypertensive medications sufficiently to truly assess foetal outcomes and health risks per drug class, Angiotensin II Receptor Antagonists/Blockers (ARBs) and Angiotensin-converting-enzyme inhibitor (ACE inhibitor) in particular. We will attempt to describe the prescription rate of ARBs and ACE inhibitors among women with very high blood pressure, plus other co-morbid conditions, in the United Kingdom (UK) and estimate the risk of serious foetal outcomes among live births.
The main objective of this study is to evaluate serious adverse fetal outcomes (diagnoses of congenital malformation in live births or post-partum infant death) in women treated with anti-hypertensive medication, more specifically, Angiotensin II Receptor Antagonists/Blockers (ARBs) and Angiotensin-converting-enzyme inhibitors (ACE inhibitors). Women who are hypertensive and pregnant will be included in the study the study period start will be from January 1, 1997 until December 31, 2014.
Where possible, each mother will be linked to data records relating to their newborn to allow analysis of adverse fetal outcomes. These outcomes will be obtained from the following sources, UK primary care data (CPRD GOLD), inpatient hospital episode statistics (HES) and Office of National Statistics (ONS) mortality data, to attempt to build a full picture of what may occur to a child when exposed to anti-hypertensive medication while in the womb. However, not all data sources will contain information on every baby identified in the cohort therefore we may have to tailor the analyses based on complete cohort size.
Although the overarching goal is to look at the impact of anti-hypertensive medication during pregnancy, other factors relating to the mothers health and circumstances such as, pre-existing diabetes or heart failure, weight and age at pregnancy start, smoking, and socio-economic status, will also be analysed in order to better understand the mother's risk profile impacting adverse fetal outcomes.
Claudia Cabrera - Chief Investigator - Astra Zeneca R&D Molndal Sweden
Claudia Cabrera - Corresponding Applicant - Astra Zeneca R&D Molndal Sweden
Alison Lee - Collaborator - Commonwealth Informatics
Cecilia Falkenberg - Collaborator - Astra Zeneca Inc - USA
Karin Henriksson - Collaborator - Astra Zeneca Inc - USA
Michael Goodman - Collaborator - Astra Zeneca Inc - USA
CPRD Mother-Baby Link;HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation