Cohort Profile: A national, population based cohort of children born after assisted conception in the UK (1992-2009) - Methodology and birthweight analysis

Mitana Purkayastha, Debbie A Lawlor, Stephen Roberts, Julian Gardener, Daniel Brison, Scott M Nelson, Barbara Luke

Research output: Contribution to journalArticle (Academic Journal)peer-review


Purpose: To generate a large cohort of children born after assisted reproductive technology (ART) in the UK between 1992 and 2009, their naturally conceived siblings (NCS), and matched naturally conceived population (NCP) controls and linking this with health outcome data to allow exploration of the effects of ART. The effects of fresh and frozen embryo transfer on birth weight were analysed to test the validity of the cohort. Participants: Children recorded on the Human Fertilisation & Embryology Authority (HFEA) register as being born after ART between 1992 and 2009, their NCS, and matched NCP controls linked to Office for National Statistics birth registration dataset (HFEA-ONS cohort). This cohort was further linked to the UK Hospital Episode Statistics database to allow monitoring of the child’s post-natal health outcomes up to 2015 (HFEA-ONS-HES sub-cohort). Findings to date: The HFEA-ONS cohort consisted of 75348 children born after non-donor ART carried out in the UK between 1st April 1992 and 31st July 2009 and successfully linked to birth registration records, 14763 NCS and 164823 matched NCP controls. The HFEA-ONS-HES sub-cohort included 63877 ART, 11343 NCS, and 127544 matched NCP controls further linked to health outcome data. The exemplar analysis showed that children born after fresh embryo transfers were lighter (BW difference: -131g, 95%CI: -140, -123) and those born after frozen embryo transfers were heavier (BW difference: 35g, 95%CI: 19, 52) than the NCP controls. The within-sibling analyses were directionally consistent with the population control analyses, but attenuated markedly for the fresh vs natural conception (BW difference: -54g; 95% CI: -72, -36) and increased markedly for the frozen vs natural conception (BW difference: 152g; 95% CI: 113, 190) analyses. Future plans: To utilise this cohort to explore the relationship between ART conception and short and long-term health outcomes in offspring. Keywords: assisted reproductive technology; birth weight; naturally conceived siblings; naturally conceived population controls; record linkage
Original languageEnglish
JournalBMJ Open
Early online date19 Jul 2021
Publication statusE-pub ahead of print - 19 Jul 2021


Dive into the research topics of 'Cohort Profile: A national, population based cohort of children born after assisted conception in the UK (1992-2009) - Methodology and birthweight analysis'. Together they form a unique fingerprint.

Cite this