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F93Feasibility of the second trimester fetal ultrasound examination in an unselected population at 18, 20 or 22 weeks of pregnancy: a randomized trial
Author(s) -
Schwärzler P.,
Ville Y.
Publication year - 2000
Publication title -
ultrasound in obstetrics and gynecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.202
H-Index - 141
eISSN - 1469-0705
pISSN - 0960-7692
DOI - 10.1046/j.1469-0705.2000.00015-1-92.x
Subject(s) - medicine , fetus , incidence (geometry) , gestational age , ultrasound , pregnancy , gestation , obstetrics , population , placenta , gynecology , radiology , genetics , physics , environmental health , optics , biology
Objective The purpose of this study was to investigate whether of three gestational ages (18, 20 and 22 weeks) any one was associated with a significant advantage in terms of identification of abnormalities, or need for further ultrasound assessment. Subjects and methods 1206 women were randomised into 3 mutually exclusive groups: group 1 at 18–18 + 6 weeks, group 2 at 20–20 + 6 weeks and group 3 at 22–22 + 6 weeks. The main end‐points were (i) need for rescan of all or part of the fetal anatomy, (ii) fetal outcome, (iii) placental localisation and (iv) incidence of notches in the uterine artery waveform. Results There was a significantly higher percentage of completed scans in group 2 (90%) and 3 (88%) than in group 1 (76%, P < 0.001), but no significant difference between those scanned at 20 and at 22 weeks. This was associated with a higher incidence of noncephalic presentation in group 1 (46%) than in the other two groups (36%, P < 0.001). Significant differences in completing the assessment of the thorax, heart, spine and skeleton were also observed. The incidence of low lying placenta and of abnormal uterine artery Doppler screening were also higher at 18 weeks than at 20 and 22 weeks ( P < 0.001 for both variables), with no difference being seen between groups 2 and 3. The number of fetal anomalies detected in the three groups were, respectively, 3, 2 and 2, and did not differ significantly between the groups. Conclusions This study suggests that among an unselected pregnant population, second trimester ultrasound screening is easier to perform and less likely to require an additional scan appointment at 20 −22 weeks than at 18 weeks.