Observational studyBMC pregnancy and childbirth2025
Accuracy of second and third trimester ultrasound in the determination of chorionicity in twin pregnancies: a cross-sectional observational study.
Observational study in BMC pregnancy and childbirth, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundDetermination of chorionicity in twin pregnancies is essential for optimizing management. In South Africa, many women first access antenatal care at late gestations. The accuracy of ultrasound in the determination of chorionicity up to 14 weeks' gestation is well documented. However, there is little data on determination of chorionicity in late pregnancy. We thus aimed to determine the accuracy of five ultrasound parameters performed after 14 weeks' gestation in determining chorionicity.
methodThis was a cross-sectional diagnostic validity study where postpartum placental histology was accepted as the standard test for chorionicity. All twin pregnancies > 14 weeks' gestation in whom chorionicity had not been determined and without any complications were included. Data collected included demographic data, ultrasound-determined number of placentae, fetal sexes, membrane 'take-off' (lambda or T-Sign), thickness, and number of layers in the dividing membrane. Placentae and membranes were examined by the Anatomical Pathology department. Each of the 5 ultrasound parameters for chorionicity was analyzed separately in relation to the corresponding histology result.
resultsA total of 85 patients were included, for whom histology was available in 58. Of these, 12 were monochorionic diamniotic and 44 dichorionic diamniotic. The diagnostic accuracies of discordant gender, number of placentas, lambda sign, membrane thickness and number of layers in the membranes were 44.1, 49.1, 76.7, 76.1 and 82.9, respectively. We developed a step-wise algorhithm for the determination of chorionicity.
conclusionDetermination of chorionicity late in twin pregnancies remains inaccurate. However, a step-wise algorithm for the application of 5 parameters is helpful.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.