Ruth Blackburn
University College London
Ruth Blackburn is an epidemiologist with experience in using big data such as electronic health data from hospitals to evaluate the impact of public health interventions. She is particularly interested in using information that is routinely recorded in health and social care settings to reduce health inequalities and develop evidence-based policy for mental health.
Objectives:
Drug dependence during pregnancy is indicative of future adversity for the mother and her child. We aimed to investigate neonatal abstinence syndrome (NAS) as a marker of drug-use in pregnancy and to compare maternal all-cause mortality relative to women without a NAS-pregnancy.
Methods:
De-identified Hospital Episodes Statistics (HES) inpatient data including hospital, GP practice, maternal age and birthweight were used for deterministic and probabilistic linkage of mothers and babies born in England between 1st April 2002 and 31st March 2014. Women who used drugs during pregnancy were identified using information from the baby’s record indicating NAS within a month of birth. All remaining mothers formed the comparison cohort. Deaths were identified from linked national mortality data. A single index birth was selected at random for each women, with the delivery date marking the start of follow-up. The association between drug use in pregnancy and the rate of mortality was modelled using Poisson regression.
Results:
The study population comprised 14,436 women with a NAS baby and 4,547,929 women without a NAS baby, corresponding to over 96% of all live births in England. On average, mothers of a NAS baby were younger at the time of delivery than those without a NAS baby (median age 28 years (IQR; 24.1-32.6) versus 30 years (IQR; 25.3-34.3), p<0.001). Ten-year mortality was 4.02 (3.63-4.46) per 1000 person years amongst mothers with a NAS baby and 0.37 (0.36-0.37) per 1000 person years for mothers without a NAS baby, yielding a crude incident rate ratio of 10.9 (95% CI 9.85-12.2).
Conclusions:
Women giving birth to infants with NAS are a population at high risk of premature mortality, and public health programs should target both infants and mothers to reduce the risk of adversity faced by these children.
