First-trimester US parameters of failed pregnancy.
OBJECTIVE
To test the reliability of established ultrasound (US) parameters in predicting the outcome of first-trimester pregnancy.


METHODS
The authors retrospectively reviewed 2,655 first-trimester US scans in 2,285 patients. Parameters tested against outcome were (a) a yolk sac and mean gestational sac diameter of 8 mm on transvaginal US scans, (b) an embryo and mean sac diameter of 16 mm on transvaginal US scans, and (c) a difference between the mean sac diameter and crown-rump length of less than 5 mm (oligohydramnios) at 5.5-9.0 weeks gestation.


RESULTS
Thirty (22%) of 135 patients without yolk sacs and with an 8-mm mean sac diameter developed live embryos: 24 had normal follow-up or delivery; six were lost to follow-up. Five (8%) of 59 patients with no depiction of embryos and with a 16-mm mean sac diameter developed live embryos: Two delivered, one spontaneously aborted, one had death of one twin embryo before being lost to follow-up, and one was lost to follow-up. Seventeen (0.74%) of 2,285 patients had early oligohydramnios: Six (35%) had normal follow-up scans or delivery, two (12%) spontaneously aborted, and nine (53%) were lost to follow-up.


CONCLUSIONS
Established parameters predictive of early pregnancy failure potentially result in misdiagnosis of nonviability or poor prognosis when applied to a large, unselected patient population. Close follow-up is necessary in cases with borderline abnormal findings.
Rowling
S E
SE
Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia 19104, USA.
Coleman
B G
BG
Langer
J E
JE
Arger
P H
PH
Nisenbaum
H L
HL
Horii
S C
SC
D000022:Abortion, Spontaneous / Q000000981:diagnostic imaging; D018568:Crown-Rump Length; D005314:Embryonic and Fetal Development; D005260:Female; D006801:Humans; D016104:Oligohydramnios / Q000000981:diagnostic imaging; D011247:Pregnancy; D011248:Pregnancy Complications / Q000000981:diagnostic imaging*; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal; D015017:Yolk Sac / Q000000981:diagnostic imaging