Fetal assessment near the limits of viability

Assessments of gestational age are critical in dealing with the pregnancy at the limits of viability, 22-25-weeks gestation, where neonatal outcomes reveal very significant differences from week to week. The obstetrical team can estimate gestational age within a window of 7-10 days during this critical threshold at the window of viability via determination of last menstrual period, bimanual exam, early pregnancy test, and/or ultrasound. One must also take into account the impact of maternal disease processes, congenital abnormalities, number of fetus(es), and/or fetal growth restriction, along with ongoing evaluation and parental involvement in this decision-making process during the peri-viability period.