Multimorbidity is when a person has two or more long-term health conditions at the same time. Examples of this would be a person who has diabetes and asthma, or a person who has high blood pressure and arthritis. The number of people living with multimorbidity is increasing throughout the whole population, including among women who will be planning to have a baby.
In the UK information about pregnancy complications such as the death of a mother or baby, or when a mother experiences a life-threatening event, is collected routinely through a number of different reporting systems. Evidence from these reporting systems suggests that women who have multimorbidity are more at risk of experiencing these complications than other women. In spite of this observation, there are still many gaps in our knowledge about pregnancy and multimorbidity.
In this study we will look at anonymous information about pregnant women in the UK taken from hospital and GP records. It will allow us to determine how many pregnant women have multimorbidity and to investigate if their pregnancy and health outcomes are different to other women. It will also allow us to see which combinations of health conditions are most common among pregnant women with multimorbidity, and if any particular type of multimorbidity is associated with poorer pregnancy outcomes for mothers and babies.
Understanding the patterns of health and disease for pregnant women with multimorbidity better will help us identify changes that could be made to the structure and delivery of maternity care to benefit women with multimorbidity.
Multimorbidity is the existence of two or more long-term health conditions in the same individual. UK-based surveillance data about death and life-threatening morbidity in pregnancy shows that women with pre-existing health conditions are more frequently affected by these outcomes. Pregnant women with multimorbidity remain an under-researched group, despite facing a disproportionate burden of morbidity and mortality.
The CPRD pregnancy register will be used to collect information on any woman who had a pregnancy between 2007-2017. Where possible, additional information about maternal and perinatal/neonatal outcomes will be obtained through the linkage of eligible women to HES, IMD scoring and ONS death registration data.
The prevalence of multimorbidity among pregnant women will be estimated, and the socio-demographic characteristics of multimorbid women will be described. Differences in maternal and perinatal/neonatal outcome between multimorbid and non-multimorbid women will be explored using odds ratios. Multivariable logistic regression will be used to explore independent factors associated with adverse outcomes. The different combinations of health conditions within the cohort and the ways they interact will be investigated using cluster analysis. Combinations of health conditions that are associated with adverse outcomes will be determined using multivariable logistic regression informed by the use of directed acyclic graphs. Multiple imputation techniques will be used to account for missing data, and to evaluate the impact of missing data on the observed associations. The most clinically relevant combinations of health conditions will be used to create a measure of severity of multimorbidity. An exploratory analysis will be undertaken to assess if the measure of severity can be used to determine individuals at greatest risk of experiencing poorer outcomes.
This study represents the starting point in establishing a comprehensive evidence-base about pregnancy and multimorbidity. It will provide novel information about a previously under-researched group, and support the development of customised maternity care.
Prevalence of multimorbidity; Prescription of pharmacotherapy; Referral to secondary care; Use of primary care services in year before pregnancy and year after birth; New diagnosis of health condition during pregnancy or in year after birth; Gestation at first antenatal care; Unplanned admission to secondary care during pregnancy; Pregnancy outcome (livebirth, stillbirth, miscarriage); Mode of birth; Gestational age at delivery; Birthweight; Neonatal resuscitation at birth; Admission to neonatal unit; Neonatal death; Maternal health event indicating severe morbidity or near-miss; Maternal admission to level 3 care; Maternal death
Rhiannon D'Arcy - Chief Investigator - University of Oxford
Rhiannon D'Arcy - Corresponding Applicant - University of Oxford
Claire Carson - Collaborator - University of Oxford
Fiona Alderdice - Collaborator - University of Oxford
Marian Knight - Collaborator - University of Oxford
Sarah Hillman - Collaborator - University of Warwick
CPRD Mother-Baby Link;HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Pregnancy Register