Extremely and Very Preterm Deliveries in a Maternity Unit of Inappropriate Level: Analysis of Socio-Residential Factors

Adrien Roussot,1,2 Karine Goueslard,1,2 Jonathan Cottenet,1– 4 Peter Von Theobald,5 Patrick Rozenberg,6,7 Catherine Quantin1– 4,8 1Biostatistics and Bioinformatics (DIM), University Hospital, Dijon, France; 2Bourgogne Franche-Comté University, Dijon, France; 3Inserm, CIC 1432, Dijon, France; 4Clinical Investigation Center, Clinical Epidemiology/Clinical Trials Unit, Dijon University Hospital, Dijon, France; 5Department of Gynecology and Obstetrics, Hospital Felix Guyon, CHU La Reunion, France; 6EA 7285, Versailles Saint Quentin University, Versailles, France; 7The Department of Obstetrics and Gynecology, Poissy-Saint Germain Hospital, Poissy, France; 8High-Dimensional Biostatistics for Drug Safety and Genomics, CESP, Inserm, Université Paris-Saclay, UVSQ, Univ. Paris-Sud, Villejuif, FranceCorrespondence: Catherine QuantinBiostatistics and Bioinformatics (DIM), University Hospital, Dijon, BP 77908, Dijon, 21079, FranceTel +33 3 8029 3629Fax +33 3 8029 3973Email catherine.quantin@chu-dijon.frPurpose: To analyze the socio-residential factors associated with extremely and very preterm deliveries occurring in non-level 3 maternity units in France.Materials and Methods: This is a population-based observational retrospective study using national hospital data from 2012 to 2014. A generalized estimating equations regression model was used to study the characteristics of women who delivered very preterm and the socio-residential risk factors for not delivering in a level 3 maternity unit at 24– 31+6d weeks of gestation.Results: Among deliveries resulting in live births and without contraindication to in-utero transfer, we identified 9198 extremely or very preterm deliveries; 2122 (23.1%) of these were managed in a non-level 3 unit. Our study showed that young maternal age (women under 20 years at delivery) was associated with the risk of giving birth prematurely in a non-level 3 maternity, and particularly in a level 1 maternity unit (adjusted relative risk, 1.53; 95% CI 1.09– 2.16). Living more than 30 minutes away from the closest level 3 unit increased the risk of delivering very preterm in a level 1 or 2 unit. Living in an urban area or urban periphery increased the risk of giving birth in a level 2 maternity unit (adjusted relative risk, 1.53; 95% CI 1.28– 1.83 and 1.42; 95% CI 1.17– 1.71, respectively).Conclusion: This study shows that young pregnant women living more than 30 minutes from a level 3 hospital have an increased risk of delivering in a maternity unit that is not equipped to deal with premature births. The risk also increases with an urban place of residence when the delivery occurs in a level 2 unit. A clearer understanding of the population at risk of delivering prematurely in a non-level 3 maternity could lead to improvements in structuring healthcare to encourage earlier management and better support.Keywords: preterm delivery, hospital claims data, neonatal intensive care unit, NICU, maternity level, socio-residential factors