Sonographic evaluation of umbilical cord thickness in monochorionic diamniotic twin pregnancies. (12th April 2022)

• Record Type: Journal Article
• Authors: Nunes, Clarissa Moraes; Biancolin, Sckarlet Ernandes; Miyadahira, Mariana Yumi; Peres, Stela Verzinhasse; de Carvalho, Mario Henrique Burlacchini; Francisco, Rossana Pulcineli Vieira; Brizot, Maria de Lourdes
• Is Part Of: Prenatal diagnosis. Volume 42:Number 5(2022)
• Page Start: 636
• Page End: 642
• Publication Date: 2022-04-12
• Subjects: Prenatal diagnosis -- Periodicals; Fetus -- Diseases -- Diagnosis -- Periodicals; Electronic journals; 618.32075
• DOI: 10.1002/pd.6141
• Languages: English
• ISSNs: 0197-3851

Abstract

Abstract: Objective: To develop a nomogram of the thickness of the umbilical cord (UC) and its components in monochorionic diamniotic (MCDA) twin pregnancies. Methods: This prospective longitudinal study involved 47 MCDA twin pregnancies (94 fetuses) between 18 and 33 weeks of gestation. Ultrasound assessments of UC cross‐sections and measurements of the umbilical cord area (UCA), the umbilical vein area (UVA), the umbilical artery area (UAA), and the Wharton jelly area (WJA) were made. The UC measurements were correlated with gestational ages. Reference values for the gestational ages of MCDA pregnancies were determined and compared with those of dichorionic twins and singletons. The cases which developed selective intrauterine growth restriction were contrasted with normal cases. Results: A positive correlation was found between all UC components and gestational age and fetal weight. The UCA of MCDA fetuses was significantly larger than that of DC fetuses ( p < 0.001) at the expense of a larger WJA ( p < 0.001) and similar to that of singleton pregnancies. The MCDA fetuses with an estimated fetal weight below the 10th percentile had a smaller UCA than fetuses with a normal estimated weight ( p < 0.001). Conclusion: The MCDA twins exhibited a thicker UC than that of dichorionic twins. Key points: What's already known about the topic? The umbilical cord can have its characteristics evaluated prenatally by ultrasound. Dichorionic fetuses have a thicker umbilical cord than single fetuses. What does this study add? Monochorionic fetuses have an umbilical cord thicker than that of dichorionic fetuses and of similar thickness as that of single fetuses. A thicker umbilical cord is due to an enlarged Whartonjelly area. The differences in cord thickness are possibly a consequence of placental shunts and amniotic fluid balance. Monochorionic growth‐restricted fetuses have thinner umbilical cords.