Dating the early pregnancy by sequential appearance of embryonic structures
| Autor: | David B. Peisner, Mortimer G. Rosen, Sashi Raju, Wendy B. Warren, Ilan E. Timor-Tritsch |
|---|---|
| Rok vydání: | 1989 |
| Předmět: |
medicine.medical_specialty
Gestational sac Physiology Gestational Age Umbilical Cord Embryonic and Fetal Development Fetal Heart Pregnancy medicine Humans Yolk sac Fetal Monitoring Ultrasonography Yolk Sac Gynecology Fetus business.industry Fetal pole Brain Obstetrics and Gynecology Gestational age medicine.disease Falx cerebri medicine.anatomical_structure Gestation Female business |
| Zdroj: | American Journal of Obstetrics and Gynecology. 161:747-753 |
| ISSN: | 0002-9378 |
| Popis: | A total of 97 transvaginal scans were performed from 4 to 12 weeks' gestation in normal and accurately dated gestations. The sequential appearance of six structures were examined: (1) the gestational sac only was present during week 4; (2) the yolk sac appeared in week 5; (3) the fetal pole with detectable heart motion was first seen in week 6; (4) the single unpartitioned ventricle in the brain marked week 7; (5) the falx cerebri appeared during week 9; and (6) the appearance and the disappearance of the physiologic midgut herniation were seen in week 8 and week 11, respectively. Inasmuch as the time in gestation at which these structures appear characterizes the gestational age more than any measurement at this age, we propose a practical method to determine the correct gestational age in early first-trimester pregnancy. |
| Databáze: | OpenAIRE |
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