Several studies have observed that women who have an eating disorder have an increased risk of adverse pregnancy outcomes such as miscarriages, babies with a low birth weight or needing a caesarean section. One small study showed mothers with an eating disorder had a higher risk of their baby having microcephaly (small head size) than mothers without an eating disorder.
The aim of this study is to use data from the CPRD to examine the outcomes of pregnancies in women with eating disorders. Adverse pregnancy outcomes will include low birth weight, high birth weight, miscarriages and births by caesarean section, delivery complications and the diagnosis of a congenital anomaly (birth defect) in the fetus/child. We will compare the adverse pregnancy outcomes between mothers who have had an eating disorder before pregnancy, mothers with an eating disorder during pregnancy and mothers without an eating disorder. The mothers without an eating disorder will be selected so that they are of a similar age to the other groups of mothers, are pregnant in the same year and attend the same GP surgeries.
The amount of data in this study will enable more precise estimates of the effects of current eating disorders on adverse pregnancy outcomes in the English population. If mothers with a past eating disorder are shown to have a higher risk of adverse pregnancy outcomes, then this may indicate that these pregnancies should be considered at a higher risk by the health care professionals looking after them.
The aim of this study is to quantify reported associations between eating disorders (ED) in pregnancy and adverse pregnancy outcomes (such as miscarriages, caesarean sections and low or high birth weights / gestational age) in this UK cohort and determine if there is an association with a history of eating disorders prior to pregnancy.
It is not expected that there will be sufficient power to detect a statistically significant increased risk of a congenital anomaly in mothers with an eating disorder, but a descriptive analysis on such a large sample of women will be informative and could prompt further research into specific congenital anomalies with a case control design.
Using pregnancies identified in the CPRD pregnancy register, the prevalence of adverse pregnancy outcomes will be compared amongst mothers with a history of an ED, mothers with an ED during pregnancy and mothers with no history of an ED matched for multiplicity, year of birth, maternal age at pregnancy and GP. Controls are selected by pregnancy and therefore a mother without an eating disorder having two pregnancies may be selected to be a control to two different pregnancies in two mothers with an eating disorder. Similarly, a mother with an eating disorder in her first pregnancy may not have a current eating disorder in her second pregnancy, only a history of an eating disorder. Therefore, in the main analysis the occurrence of siblings will be ignored. A sensitivity analysis will be performed including only each womens first pregnancy occurring in the cohort.
Potential confounders, such as maternal smoking and alcohol consumption will be adjusted for using propensity score matching (for example women who smoke may be more likely to have eating disorders). Multiple births, maternal age and deprivation will be adjusted for through the matching.
Primary Outcomes : Adverse pregnancy outcomes including low birth weight, high birth weight, small for gestational age, miscarriages, births by caesarean section, any delivery complications and any diagnoses of a congenital anomaly, with an emphasis on major congenital anomalies as defined by EUROCAT Guide 1.4 (www.eurcat-network.eu/aboutus/datacollection/guidelinesforregistration/…). For twin pairs all twins with the the lowest birthweight will be compared and separately all twins with the highest birthweight will be compared.
Joan Morris - Chief Investigator - St George's, University of London
Joan Morris - Corresponding Applicant - St George's, University of London
Derek Cook - Collaborator - St George's, University of London
Iain Carey - Collaborator - St George's, University of London
Tess Harris - Collaborator - St George's, University of London
CPRD Mother-Baby Link;HES Admitted Patient Care;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation;Pregnancy Register