title: Plasma estriol in the evaluation of third-trimester gestational age.
abstract: This study attempts to confirm previous reports of a clinically useful serum unconjugated estriol surge at 36 weeks' gestation. Although an apparently physiologic estriol surge occurred at 36 +/- 2.1 weeks in 25 of 32 patients, clinical reality makes weekly plasma sampling difficult. In individual cases, use of the "surge point" predicted gestational age within a 4-week range with only 66% accuracy, and potentially serious errors in dating occurred. Other biochemical (lecithin:sphingomyelin, phosphatidylglycerol) and sonographic methods are superior in resolving problems with dating gestational age in the third trimester.
mesh_terms: D004964:Estriol / Q000097:blood*; D005260:Female; D005323:Fetal Monitoring / Q000379:methods; D005333:Fetus / Q000502:physiology*; D005865:Gestational Age; D006801:Humans; D008168:Lung / Q000196:embryology; D011247:Pregnancy; D011263:Pregnancy Trimester, Third
chemical_list: D004964:Estriol