Why we succeed and fail in detecting fetal growth restriction: A population-based study.

Introduction: The objective of this study was to explore the association between detection of fetal growth restriction and maternal-, healthcare provider- and organizational factors.

Material And Methods: A historical, observational, multicentre study. All women who gave birth to a child with a birthweight <2.3rd centile from 1 September 2012 to 31 August 2015 in Zealand, Denmark, were included. The population was identified through the Danish Fetal Medicine Database. Medical charts were reviewed to obtain data regarding maternal characteristics and information on the healthcare professionals. Date of authorization for the midwives and obstetricians involved was extracted from the Danish Health Authorization Registry. Multivariable Cox regression models were used to identify predictors of antenatal detection of fetal growth restriction, and analyses were adjusted for hospital, body mass index, parity, the presence of at least one risk factor and experience of the first midwife, number of midwife visits, number of visits to a doctor, the experience of the consultant midwife or the educational level of the doctor, the number of scans and gaps in continuity of midwife-care. Antenatal detection was defined as an ultrasound estimated fetal weight <2.3rd centile (corresponding to -2 standard deviations) prior to delivery.

Results: Among 78 544 pregnancies, 3069 (3.9%) had a fetal growth restriction. Detection occurred in 31% of fetal growth-restricted pregnancies. Clinical experience (defined as years since graduation) of the first consultation midwife was positively associated with detection, with a hazard ratio [HR] of 1.15, 95% confidence interval [CI] 1.03-1.28), for every 10 years of additional experience. The hazard of detection increased with the number of midwife consultations (HR 1.15, 95% CI 1.05-1.26) and with multiparity (HR 1.28, 95% CI 1.03-1.58). After adjusting for all covariates, an unexplained difference between hospitals (P = .01) remained.

Conclusions: The low-risk nullipara may constitute an overlooked group of women at increased risk of antenatal non-detection of fetal growth restriction. Being screened by experienced midwives during early pregnancy and having access to multiple midwife consultations may improve future diagnosis.