An Ectopic Pregnancy happens when a pregnancy starts growing outside of the womb. This usually happens in the fallopian tubes, which are tubes that carry a new pregnancy to the womb. These pregnancies will not usually survive longer than 8 weeks, as the body cannot support the growing baby outside of the womb. Ectopic pregnancies need to be treated to end the pregnancy before they cause complications like a ruptured ectopic pregnancy, which is where the fallopian tube splits open and can cause life-threatening bleeding. Ectopic pregnancies are the leading cause of death in early pregnancy, and can cause fertility issues.
We have seen trends in national data which suggest that the rate at which ectopic pregnancies happen is changing, especially across different age groups, and may be rising in young women. The reason for this is not clear, and so this study is trying to confirm if this change in the rate of ectopic pregnancy is happening, and explain this change using what is already known about ectopic pregnancies. If we confirm a rise in ectopic pregnancies, this will affect the care offered during early pregnancy. If we cannot explain this change in terms of what is already known about ectopic pregnancy, it may mean there is a new cause of ectopic pregnancy that needs further research to identify and treat the cause. This will enable health services to prevent ectopic pregnancies, and the risks that ectopic pregnancies pose to life and to fertility.
The incidence of ectopic pregnancy may be rising in women aged under 20 and population epidemiological risk factors do not explain this trend. Confirming this trend is challenging because many pregnancies that could have been ectopic (typically up to 8 weeks, after which ectopics are rarely viable) are not recorded, varying according to outcome such as miscarriage, and the pregnancies are missing at random. We will calculate a denominator of conceptions at risk using the CPRD pregnancy register and adjust the sample using prior estimates of the probability of miscarriage, termination, stillbirth and livebirth. Ascertainment of ectopic pregnancy, ruptured ectopic pregnancy, miscarriage, termination, stillbirth and livebirth will be supplemented by linkage with CPRD Aurum and HES APC diagnostic and procedure codes. Incidence will be calculated per pregnancy, and incidence and prevalence per included participant. Subgroup analyses will be calculated by age, ethnicity, and deprivation, using individual- and practice-level Index of Multiple Deprivation derived from linked area data to identify health inequalities of ectopic pregnancies. Outputs and covariates will be extracted from the linked primary and secondary care records per mother and per pregnancy. We will also fit a logistic regression model adjusting for known causes and risk factors for ectopic pregnancy, drawn from CPRD Aurum data, exploring if these covariates can explain residual risks in subgroups, to support future hypothesis generation about causes of changing trends. This study is important because no data on ectopic pregnancy has been published in the UK since 2008 and no data on ethnicity or other dimensions of deprivation (inequality) in ectopic pregnancies have ever been published to our knowledge.
Ruptured ectopic pregnancy;
Ectopic pregnancy;
Neil Cockburn - Chief Investigator - University of Birmingham
Neil Cockburn - Corresponding Applicant - University of Birmingham
Arturo Gonzalez-Izquierdo - Collaborator - University of Birmingham
Joht Singh Chandan - Collaborator - University of Birmingham
Katherine Phillips - Collaborator - University of Birmingham
Krishnarajah Nirantharakumar - Collaborator - University of Birmingham
Rowland Seymour - Collaborator - University of Birmingham
William Parry-Smith - Collaborator - Keele University
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation;CPRD Aurum Pregnancy Register