Macrosomia: mode of delivery and pregnancy outcome.
OBJECTIVE
To assess associations between birthweight and selected adverse outcomes in vaginal and cesarean deliveries and to clarify to which extent macrosomic births are delivered by cesarean section or are centralized to larger maternity units.


METHODS
Cohort study.


METHODS
National study based on the Medical Birth Registry of Norway.


METHODS
All births in Norway for the duration 1999-2005 comprising 304,968 vaginal and 47,702 cesarean deliveries.


METHODS
Rates of adverse pregnancy outcomes by birthweight in vaginal and cesarean deliveries were compared by odds ratios (ORs) obtained in logistic regression analysis with birthweight 2,500-3,999 g as the reference and adjusted for maternal age, birth order and size of maternity unit.


METHODS
Analgesia, interventions, complications and neonatal outcomes.


RESULTS
For all the adverse outcomes, the ORs increased continuously from the reference group up to > or =5,000 g in which the highest adjusted ORs were observed for shoulder dystocia [64.2 (confidence interval 55.7-74.0)] and plexus injuries [47.7 (confidence interval 35.7-62.4)]. The proportion of adverse outcomes attributable to macrosomia (birthweight > or =4,500 g) ranged from 56.8% of all shoulder dystocia cases to 0.5% of all stillbirths. Macrosomic births were not centralized to larger maternity units and planned cesarean delivery was not more frequent in macrosomic births.


CONCLUSIONS
Macrosomic births involved excess risks of a series of adverse pregnancy outcomes, the births were not centralized to larger maternity units and planned cesarean section was not more frequent in macrosomic births.
Locus for Registry Based Epidemiology, Department of Public Health and Primary Health Care, University of Bergen, Kalfarveien 31, Bergen, Norway.
Astrid R
AR
Bjørstad
Kaja
K
Irgens-Hansen
Anne Kjersti
AK
Daltveit
Lorentz M
LM
Irgens
D000293:Adolescent; D000328:Adult; D001034:Apgar Score; D001724:Birth Weight; D002585:Cesarean Section / Q000706:statistics & numerical data; D015331:Cohort Studies; D016001:Confidence Intervals; D036861:Delivery, Obstetric / Q000379:methods*; D005260:Female; D005320:Fetal Macrosomia / Q000000981:diagnostic imaging*; D005865:Gestational Age; D006801:Humans; D007226:Infant Mortality / Q000639:trends*; D007231:Infant, Newborn; D008423:Maternal Age; D008875:Middle Aged; D009321:Natural Childbirth / Q000706:statistics & numerical data; D009664:Norway; D007744:Obstetric Labor Complications / Q000175:diagnosis / Q000453:epidemiology; D016017:Odds Ratio; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome; D012042:Registries; D018570:Risk Assessment; D016216:Ultrasonography, Prenatal; D055815:Young Adult