TY - JOUR
T1 - Adverse Infant Outcomes Associated with Discordant Gestational Age Estimates
AU - the PREBIC Epidemiology Working Group
AU - Morken, Nils Halvdan
AU - Skjærven, Rolv
AU - Richards, Jennifer L.
AU - Kramer, Michael R.
AU - Cnattingius, Sven
AU - Johansson, Stefan
AU - Gissler, Mika
AU - Dolan, Siobhan M.
AU - Zeitlin, Jennifer
AU - Kramer, Michael S.
N1 - Publisher Copyright:
© 2016 John Wiley & Sons Ltd
PY - 2016/11/1
Y1 - 2016/11/1
N2 - Background: Gestational age estimation by last menstrual period (LMP) vs. ultrasound (or best obstetric estimate in the US) may result in discrepant classification of preterm vs. term birth. We investigated whether such discrepancies are associated with adverse infant outcomes. Methods: We studied singleton livebirths in the Medical Birth Registries of Norway, Sweden and Finland and US live birth certificates from 1999 to the most recent year available. Risk ratios (RR) with 95% confidence intervals (CI) by discordant and concordant gestational age estimation for infant, neonatal and post-neonatal mortality, Apgar score <4 and <7 at 5 min, and neonatal intensive care unit (NICU) admission were estimated using generalised linear models, adjusting for maternal age, education, parity, year of birth, and infant sex. Results were presented stratified by country. Results: Compared to infants born at term by both methods, infants born preterm by ultrasound/best obstetric estimate but term by LMP had higher infant mortality risks (range of adjusted RRs 3.9 to 7.2) and modestly higher risks were obtained among infants born preterm by LMP but term by ultrasound/best obstetric estimate (range of adjusted RRs 1.6 to 1.9). Risk estimates for the other outcomes showed the same pattern. These findings were consistent across all four countries. Conclusions: Infants classified as preterm by ultrasound/best estimate, but term by LMP have consistently higher risks of adverse outcomes than those classified as preterm by LMP but term by ultrasound/best estimate. Compared with ultrasound/best estimate, use of LMP overestimates the proportion of births that are preterm.
AB - Background: Gestational age estimation by last menstrual period (LMP) vs. ultrasound (or best obstetric estimate in the US) may result in discrepant classification of preterm vs. term birth. We investigated whether such discrepancies are associated with adverse infant outcomes. Methods: We studied singleton livebirths in the Medical Birth Registries of Norway, Sweden and Finland and US live birth certificates from 1999 to the most recent year available. Risk ratios (RR) with 95% confidence intervals (CI) by discordant and concordant gestational age estimation for infant, neonatal and post-neonatal mortality, Apgar score <4 and <7 at 5 min, and neonatal intensive care unit (NICU) admission were estimated using generalised linear models, adjusting for maternal age, education, parity, year of birth, and infant sex. Results were presented stratified by country. Results: Compared to infants born at term by both methods, infants born preterm by ultrasound/best obstetric estimate but term by LMP had higher infant mortality risks (range of adjusted RRs 3.9 to 7.2) and modestly higher risks were obtained among infants born preterm by LMP but term by ultrasound/best obstetric estimate (range of adjusted RRs 1.6 to 1.9). Risk estimates for the other outcomes showed the same pattern. These findings were consistent across all four countries. Conclusions: Infants classified as preterm by ultrasound/best estimate, but term by LMP have consistently higher risks of adverse outcomes than those classified as preterm by LMP but term by ultrasound/best estimate. Compared with ultrasound/best estimate, use of LMP overestimates the proportion of births that are preterm.
KW - Gestational age estimation
KW - best obstetric estimate
KW - infant outcome
KW - last menstrual period
KW - ultrasound
UR - http://www.scopus.com/inward/record.url?scp=84992466659&partnerID=8YFLogxK
U2 - 10.1111/ppe.12311
DO - 10.1111/ppe.12311
M3 - Article
C2 - 27555359
AN - SCOPUS:84992466659
SN - 0269-5022
VL - 30
SP - 541
EP - 549
JO - Paediatric and Perinatal Epidemiology
JF - Paediatric and Perinatal Epidemiology
IS - 6
ER -