ABSTRACT
PURPOSE: To determine whether gestational sac volume (GSV) or amniotic sac volume (ASV) and/or the difference between them can predict abortion in women with first-trimester threatened abortion. METHODS: Ninety patients between 6 and 12 weeks of gestation presenting with vaginal bleeding were studied. Seventy-six delivered after 24 weeks of gestation (group A) and 14 aborted before 20 weeks of gestation (group B). All patients had a singleton viable pregnancy demonstrated by transvaginal ultrasound. Gestational sac and amniotic sac volumes were measured in all the patients using three-dimensional transvaginal ultrasound with Virtual Organ Computer-aided Analysis software, and the gestational sac volume - amniotic sac volume (GSV - ASV) was calculated. RESULTS: The groups did not differ in terms of age, parity, number of previous abortions, or term deliveries. The GSV (group A: mean 32.0 ± 27.7 cm(3) ; group B: 26.7 ± 29.1 cm(3) ) and the ASV (group A: 21.1 ± 25.5 cm(3) ; group B: 20.6 ± 26.0 cm(3) ) were not statistically different, while the GSV - ASV was significantly smaller in group B (aborting before week 20) (group A: 10.9 ± 10.9 cm(3) ; group B: 6.1 ± 8.6 cm(3) ; p < 0.05). Using receiver operator curves, the area under the curve for predicting normal pregnancy outcome of the GSV - ASV measurement was 0.654. When the GSV - ASV was 1.8 cm(3) or less, abortion was predicted with 84% sensitivity and 43% specificity. CONCLUSIONS: The measurement of the GSV and the ASV are not good predictors of abortion in patients with first-trimester vaginal bleeding, whereas the use of the GSV - ASV may be helpful in predicting the outcome of pregnancy.
Subject(s)
Abortion, Spontaneous/diagnostic imaging , Amnion/diagnostic imaging , Gestational Sac/diagnostic imaging , Pregnancy Trimester, First , Ultrasonography, Prenatal/methods , Abortion, Threatened/diagnostic imaging , Adolescent , Adult , Amnion/anatomy & histology , Female , Gestational Age , Gestational Sac/anatomy & histology , Humans , Middle Aged , Organ Size , Pregnancy , ROC Curve , Sensitivity and Specificity , Young AdultABSTRACT
OBJECTIVE: The purpose of this study was to measure the volumes of the gestational sac and amniotic sac in normal pregnancies during the first trimester with 3-dimensional sonography to prepare nomograms. METHODS: One hundred fifty-one patients between 6 and 12 weeks' gestation were studied. Nine aborted and were excluded, leaving 142 patients for evaluation. Inclusion criteria were a singleton viable pregnancy shown by transvaginal sonography and continuation of the pregnancy beyond 24 weeks. Women with known thrombophilia or fetal malformations were excluded. In all patients, gestational sac and amniotic sac volumes were measured by 3-dimensional transvaginal sonography with virtual organ computer-aided analysis software. RESULTS: The mean gestational sac volume was 20.35 mL (range, 0.7-113 mL) and correlated closely with the gestational age (GA) (r2 = 0.769; P << .001) and crown-rump length (CRL) (r2 = 0.823; P << .001). The mean amniotic sac volume was 3.69 mL (range, 0.01-92.1 mL) and also had a strong correlation with the GA (r2 = 0.869; P << .001) and CRL (r2 = 0.919; P << .001). CONCLUSIONS: Gestational sac and amniotic sac volumes show excellent correlation with the GA and CRL and hence may be used for determining the GA. Larger studies are needed to determine the importance of these volumes in predicting normal pregnancy outcomes and whether these volumes can be used in the management of pregnancies at risk for abortion.
