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‍Why does this matter?

ECHILD contains data about children from schools, hospitals and children’s social care. However, some key bits of information are missing. Adding information on maternal characteristics (such as age, education, and health needs) could help inform the best ways to support young adults in becoming parents. Adding in data on mothers via a mother-baby link allows us to answer more research questions and generate evidence about the best ways to support families.

‍What did we want to find out?

‍Research consistently demonstrates strong influences of parental physical health and family characteristics on child outcomes, including child mental health, learning and risky behaviours[HK1] . Consultations with Government and the third sector have highlighted that information on parent/family characteristics is critically important for policies and services supporting vulnerable families. However, population-level data linking parental and family characteristics with children’s health and education outcomes across the lifecourse is lacking.

‍What we did

‍We created a set of rules that use de-identified information recorded in hospital data for babies and mothers (e.g. birthweight, hospital provider, dates) to find which records belonged to the same mother-baby pair. We checked our methods using data from community services that already holds information for mothers and babies together, to ensure that our linkage was accurate.

‍What we found

‍We linked 13.6 million baby records to the delivery records of 8.0 million mothers. The linked cohort captures almost 9 in 10 of all live births in England for mothers aged up to 37. The cohort is representative of national birth statistics.

What this means, and what's next

ECHILD now provides a way of identifying disadvantage and vulnerability in children through linking with maternal exposures. We can also use information on siblings to better understand how changing exposures might impact on child outcomes. We will continue to update the mother-baby link as new data become available. ‍ ‍

Introduction: 

Maternal physical, psychological and social risk factors extend beyond affecting mothers' individual wellbeing to significantly influence their children. Recognising the intricate interplay of these factors within families and across generations is pivotal for designing targeted interventions to enhance the health and wellbeing of current and future generations.

Methods: 

HES captures separate records of births for babies and deliveries for mothers in NHS hospitals. We first identified birth records and delivery records between 1 April 1997 and 31 January 2022 from HES data using validated code lists. In HES, delivery episodes for mothers and birth episodes for babies include additional fields on delivery procedures and outcomes, which are called the baby/maternity tail. The baby/maternity tail ideally contains the same information in delivery and birth records, but is sometimes incomplete.

We then used a previously validated algorithm for linking delivery and birth records. We performed deterministic linkage using seven linking variables (including location, delivery and birth characteristics), and probabilistic linkage using 23 linking variables for the remaining unlinked records. Record pairs with implausible dates were not considered; for example, babies discharged prior to the mother’s admission, or mothers discharged prior to the baby’s admission.

ECHILD data used:

HES: Admitted Patient Care (1997/98 to January 2022)

Results:

In total, 13. 6 million of 14.5 million birth records (94.1%) were linked to delivery records. The linkage rate varied by year, with the lowest linkage rate in 1997 (89.5%) and 1998 (89.4%), and the highest linkage rate in 2010 (96.2%); the linkage rate for singleton births was higher than for multiple births (94.4% vs 80.7%). Linkage rates also varied by hospital and ethnic group. We estimated the positive predictive value to be 99.3% and sensitivity to be 97.8%, based on a reference-standard dataset. The linked dataset is representative of national birth statistics published by the Office for National Statistics.  

Conclusions: 

The ECHILD mother-baby cohort serves as a valuable resource for investigating intergenerational effects of maternal exposure before and during pregnancy on children's health, education and social care outcomes. As the cohort matures, the extended follow-up will enable further comprehensive analyses. These data will be instrumental in identifying vulnerable children at heightened risk of adverse outcomes, informing the design of early intervention strategies for targeted and effective support.

‍ Published papers:

‍Data Resource Profile: A national linked mother-baby cohort of health, education and social care data in England (ECHILD-MB)

‍Data Resource Profile: ECHILD only-children and siblings (ECHILD-oCSib): a national cohort of linked health, education and social care data on mothers and children in England