- Errol R Norwitz, MD, PhD, MBA
Errol R Norwitz, MD, PhD, MBA
- Professor and Chair
- Department of Obstetrics and Gynecology
- Tufts Medical Center and Tufts University School of Medicine
The timely onset of labor and delivery is an important determinant of perinatal outcome. Both preterm and postterm births are associated with higher rates of perinatal morbidity and mortality than pregnancies delivering at term.
The American College of Obstetricians and Gynecologists defines postterm pregnancy as ≥420/7ths weeks of gestation (≥294 days from the first day of the last menstrual period) .
The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) 2015 uses the term prolonged pregnancy, which includes postdates and postterm pregnancy. A postterm fetus is defined as ≥420/7ths weeks of gestation (≥294 days from the first day of the last menstrual period) .
Of note, early term is defined as 370/7ths to 386/7ths weeks of gestation, full term is defined as 390/7ths to 406/7ths weeks of gestation, and late term is 410/7ths to 416/7ths weeks of gestation [1,3].
In the United States in 2013, approximately 5.5 percent of pregnancies delivered at ≥42 weeks and 8.5 percent delivered at 41 weeks . A study of postterm birth rates in 13 European countries observed a wide range across the continent: from 0.4 percent in Austria and Belgium to 8.1 percent in Denmark . The authors attributed the variation to differences in prenatal assessment of gestational age and obstetric practices.
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- ETIOLOGY AND RISK FACTORS
- MORBIDITY AND MORTALITY
- Fetal and neonatal complications
- - Macrosomia
- - Dysmaturity
- - Perinatal mortality
- - Other
- Maternal complications
- Our approach: Induction
- Alternative approach: Expectant management with fetal monitoring
- - Indications for delivery
- RECURRENCE RISK
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS