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Prenatal surveillance vital in monochorionic twin pregnancies


Prenatal care is important for every pregnancy. It ensures the health and safety of the mother and baby throughout gestation, and alerts the ob.gyn. to any possible complications that may arise. Today, more than ever before, we have a wide array of powerful tools to augment the care we provide for our patients – from imaging technologies, to genomic screens, to advances in fetal surgery. However, every pregnancy can present its own set of challenges, and successful delivery of a healthy newborn cannot be taken for granted.

The importance of proper prenatal care is most essential to women with higher-risk pregnancies, which includes those involving multiple fetuses. From the babies’ perspective, complications of multiple fetuses can include intrauterine growth restriction, cerebral palsy, and stillbirth; from the mother’s perspective, complications of multiple fetuses can include preterm labor, gestational diabetes mellitus, preeclampsia, and placental abruption.

Dr. E. Albert Reece

Dr. E. Albert Reece

Twin births are the most common multiple births and, in the United States, account for a little more than 3% of all live births. Active vigilance on the part of the mother and her ob.gyn. begins once twins have been identified and their chorionicity is established, ideally within the first trimester. Dichorionic twins and monochorionic twins cannot be treated in exactly the same manner. For example, according to the American College of Obstetricians and Gynecologists, dichorionic twins with no complications should be delivered at 38 weeks’ gestation, and monochorionic twins with no complications should be delivered between 34 and 38 weeks’ gestation (Obstet Gynecol. 2013;121:908-10).

This month, we focus on the range of tools and approaches used to treat complications that can occur in monochorionic twin pregnancies, including twin-to-twin transfusion syndrome, selective fetal growth restriction, twin anemia polycythemia sequence, and twin reversed arterial perfusion. Despite the challenges these conditions pose, increased ultrasonographic and echocardiographic surveillance allow for earlier detection and possible intervention to slow progression or, in some cases, correct defects that would have terminated the pregnancy not too long ago. Additionally, fetal therapy programs utilizing in-utero surgical techniques, such as fetoscopic laser coagulation, have significantly broadened the management and treatment options we can now offer these patients.

Dr. M. Ozhan Turan, an associate professor and director of fetal therapy and complex obstetric surgery in the department of obstetrics, gynecology, and reproductive sciences at the University of Maryland School of Medicine, provides an overview of these techniques and technologies which, when applied appropriately, can significantly improve pregnancy outcomes.

Dr. Reece, who specializes in maternal-fetal medicine, is vice president for medical affairs at the University of Maryland, Baltimore, as well as the John Z. and Akiko K. Bowers Distinguished Professor and dean of the school of medicine. Dr. Reece said he had no relevant financial disclosures. He is the medical editor of this column. Contact him at

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