This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bahtiyar, M. O. Articles by Copel, J. A. Search for Related Content PubMed PubMed Citation Articles by Bahtiyar, M. O. Articles by Copel, J. A.

Prevalence of Congenital Heart Defects in Monochorionic/Diamniotic Twin Gestations

A Systematic Literature Review

Departments of Obstetrics, Gynecology, and Reproductive Sciences (M.O.B., A.T.D., J.A.C.), and Pediatrics (B.P.W., A.H.F.), Yale University School of Medicine, New Haven, Connecticut USA.

Address correspondence to Mert Ozan Bahtiyar, MD, Section of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, 333 Cedar St, PO Box 208063, New Haven, CT 06520 USA. E-mail: mert.bahtiyar{at}yale.edu

Objective. Congenital heart defects (CHDs) affect approximately 0.5% of all neonates. Recent literature points to a possible increase in the CHD prevalence among monochorionic/diamniotic (MC/DA) twin gestations. We hypothesized that MC/DA twin pregnancy is a risk factor for CHD. Methods. A systematic review of all published English literature was conducted on MEDLINE (Ovid and PubMed) from January 2000 through April 2007 using the medical subject heading terms "congenital heart defect" and "monozygotic twins." Four observational studies were included in the final analysis. Published historical data were used for the population background risk of CHD. Relative risk (RR) estimates with 95% confidence intervals (CIs) were calculated by fixed and random effect models. Results. We included a total of 40 fetuses with CHDs among 830 fetuses from MC/DA twin gestations. Compared with the population, CHDs were significantly more prevalent in MC/DA twins regardless of the presence of twin-twin transfusion syndrome (TTTS) (RR, 9.18; 95% CI, 5.51–15.29; P < .001). Monochorionic/diamniotic twin gestations affected by TTTS were more likely to be complicated by CHDs than those that did not have TTTS (RR, 2.78; 95% CI, 1.03–7.52; P = .04). Ventricular septal defects were the most frequent heart defects. Pulmonary stenosis and atrial septal defects were significantly more prevalent in pregnancies complicated with TTTS. Conclusions. Monochorionic/diamniotic twin gestation appears to be a risk factor for CHDs. Conditions that lead to abnormal placentation may also contribute to abnormal heart development, especially in MC/DA twin pregnancies complicated with TTTS. Fetal echocardiography may be considered for all MC/DA twin gestations because ventricular septal defects and pulmonary stenosis are the most common defects.

Key Words: congenital heart defect • monochorionic • twin pregnancy • twins • twin-twin transfusion syndrome

Abbreviations: CHD, congenital heart defect • CI, confidence interval • MC/DA, monochorionic/diamniotic • RR, relative risk • TTTS, twin-twin transfusion syndrome • VEGF, vascular endothelial growth factor

This article has been cited by other articles:

				P.O.D. Pharoah and Y. Dundar Monozygotic twinning, cerebral palsy and congenital anomalies Hum. Reprod. Update, November 1, 2009; 15(6): 639 - 648. [Abstract] [Full Text] [PDF]

				N. Oyen, G. Poulsen, H. A. Boyd, J. Wohlfahrt, P. K.A. Jensen, and M. Melbye Recurrence of Congenital Heart Defects in Families Circulation, July 28, 2009; 120(4): 295 - 301. [Abstract] [Full Text] [PDF]

				O. M. Faye-Petersen and T. M. Crombleholme Twin-to-Twin Transfusion Syndrome: Part 2. Infant Anomalies, Clinical Interventions, and Placental Examination NeoReviews, September 1, 2008; 9(9): e380 - e392. [Abstract] [Full Text] [PDF]

				M. O. Bahtiyar and J. A. Copel Improving Detection of Fetal Cardiac Anomalies: A Fetal Echocardiogram for Every Fetus? J. Ultrasound Med., December 1, 2007; 26(12): 1639 - 1641. [Full Text] [PDF]