The Clinical Practice Research Datalink (CPRD) Mother-Baby Links: A Data Resource Profile

Maternal exposures before, during and after pregnancy can affect the infant. It is therefore important that researchers study mothers and their children. The CPRD GOLD Mother-Baby Link (MBL) algorithm was applied to the CPRD Aurum database, to extend the useful tool. Here, we present the algorithm and data resource profiles of the CPRD MBLs.

Records of female patients registered with a CPRD practice between the 1st January 1987 and the 1st June 2023 were searched for evidence of delivery. Infants born and registered between 1st January 1987 and 1st June 2023 were matched to mothers on practice and household indicators. The resulting MBLs were characterised.

The CPRD MBL algorithm was applied to the CPRD databases resulting in nearly four-million mother-baby pairs: 2.4-million in CPRD Aurum. Mothers in the CPRD GOLD and CPRD Aurum MBL's were similar in terms of age; mean age 29.6 years (SD = 5.7) vs. 30.2 years (SD = 5.7), and length of GP registration; mean = 14.4 years (SD = 10.9) vs. mean = 13.7 (SD = 10.9). The median number of matches was slightly higher in the CPRD GOLD MBL; 2 (IQR = 1, 2) vs. 1 (IQR = 1, 2). The number of matches in both databases peaked in 2008-2011, followed by a steady decline to 2023.

The CPRD MBL's offer a valuable tool for researchers to study the mother-infant relationship. Extending the CPRD MBL algorithm to CPRD Aurum has increased the capacity for researchers to investigate rarer exposures and outcomes.