An evaluation of the time of discovery of fetal malformations by an indication-based system for ordering obstetric ultrasound.
Circumstances of detection of 570 structural abnormalities in 364 fetuses were reviewed to determine whether referral for obstetric ultrasound according to specific indications resulted in late detection of abnormal fetuses and whether earlier detection might have changed pregnancy outcomes. A system of indication-based obstetric ultrasound discovered 124 abnormal fetuses (34%) at 22 weeks or less and 240 (66%) at 23 weeks or more. Most fetal abnormalities found at 23 weeks or more were probably detectable earlier, because the pattern of abnormalities discovered was reasonably similar in the two groups. Discovery of abnormal fetuses at 22 weeks or less was associated with a 67% termination rate and an 11% postnatal survival rate, whereas discovery at 23 weeks or more was associated with a 14% termination rate and a 51% postnatal survival rate. For fetal abnormalities not detected until 23 weeks or more, the indications that led to detection were present earlier in only 28%, and any indications were present earlier in only 44%. This study raises serious concern about the ability of the indication-based obstetric ultrasound system commonly used in the United States to detect fetal abnormalities before therapeutic options become limited. Evaluation of alternative systems for timing of obstetric ultrasound appears to be warranted.
Hegge
F N
FN
Department of Obstetrics, Emanuel Hospital, Portland, Oregon.
Franklin
R W
RW
Watson
P T
PT
Calhoun
B C
BC
D000013:Congenital Abnormalities / Q000175:diagnosis*; D005260:Female; D006801:Humans; D011237:Predictive Value of Tests; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D012189:Retrospective Studies; D013997:Time Factors; D014463:Ultrasonography / Q000379:methods*