Short summary

The aim of this study is to investigate whether there is an association between mode of delivery and risk of rheumatoid arthritis, diabetes mellitus, and celiac disease among the offspring.

Rationale

The aim of this study is to investigate whether there is an association between mode of delivery and risk of rheumatoid arthritis, diabetes mellitus, and celiac disease among the offspring. We work with three hypotheses:

• Persons delivered by caesarean section have a greater risk of (a (juvenile) diagnosis of) rheumatoid arthritis and diabetes mellitus, but not celiac disease, than persons born by vaginal delivery
• Persons delivered by caesarean section have a diagnosis of rheumatoid arthritis or diabetes mellitus, but not celiac disease, at a younger age than persons born by vaginal delivery
• If an association in hypothesis one or two exists, the effect may differ by the patients gender

In order to investigate these hypotheses we will use data linkage. Data from all sources are linked using The National Register of Persons (CPR-number). CPR-number is assigned at birth. The CPR-number encodes date of birth and sex of the person, allowing calculation of age at any time. The Medical Birth Registry contains information on maternal and paternal CPR number of each newborn, enabling identification of parental history of hospitalizations and medication use. We will analyze the possible impact of mode of delivery on subsequent risk by log-linear Poisson regression models. We will analyze data separately for rheumatoid arthritis, diabetes mellitus and celiac disease and for the combined diagnoses

Description of the cohort

The study includes all children born alive in Denmark, between 1 January 1977 and 31 December 2011, identified through The Medical Birth Registry. The registry has tracked all home- and hospital-based births in Denmark since 1973. Children born as part of multiple gestation are excluded.

Data and biological material

Data from The National Register of Persons, The Medical Birth Registry and The National Patient Registry will be used for data linkage.

Collaborating researchers and departments

OPEN Odense Patient data Explorative Network, Odense University Hospital

• Professor and Consultant Epidemiologist Anders Green, DMSc, PhD

Department of Epidemiological Research, The National Institute for Health Data and Disease Control

• Morten Frisch, MD, "DMSc, PhD

Institute of Regional Health Services Research, Faculty of Health Sciences, University of Southern Denmark

• Clinical Associated Professor Vibeke Andersen, MD, PhD
• Professor Kim Hørslev-Petersen, MD, DMSc

Publications associated with the project

Andersen V, Pedersen AK, Möller S, Green A. Chronic Inflammatory Diseases - Diabetes Mellitus, Rheumatoid Arthritis, Coeliac Disease, Crohn's Disease, and Ulcerative Colitis Among the Offspring of Affected Parents: A Danish Population-Based Registry Study. Clin Epidemiol. 2021 Jan 7;13:13-20. doi: 10.2147/CLEP.S286623. PMID: 33442298; PMCID: PMC7800432.