The Center for Fetal Diagnosis and Treatment at CHOP serves more than 150 families with complicated multiples pregnancies each year and performs more than 50 fetoscopic laser surgeries annually, one of the highest volumes of prenatal laser surgeries in the nation.
A multiyear study at CHOP looked at the neurocognitive effects of twin-twin transfusion syndrome (TTTS) in monochorionic twins who underwent in utero laser surgery. The study’s goal was to provide families more accurate information on what to expect before and after birth and to identify any long-term consequences.
“Overall, there were high rates of normal neurodevelopmental outcomes in these children at age 2,” said Nahla Khalek, MD, MPH, FACOG, a CHOP maternal-fetal medicine and clinical genetics specialist who led the study.
TTTS occurs before birth in about 10 to 15 percent of monochorionic twins who share one placenta but each have their own amniotic sac. The shared placenta contains blood vessels connecting both fetuses, and TTTS results from a blood flow imbalance. The smaller twin (donor) pumps blood to the larger twin (recipient), causing the recipient twin to receive too much blood and the donor to receive too little. Without intervention, TTTS results in the death of one or both fetuses in 80 to 100 percent of cases.
Dr. Khalek and colleagues analyzed two-year neurodevelopmental outcomes in 29 pairs of twins with TTTS who underwent selective laser photocoagulation (SLPC) of placental anastomoses in utero at CHOP between 2009 and 2011. This minimally invasive procedure uses a laser fiber inserted through a fetoscope to identify and disconnect all of the identifiable connecting blood vessels, allowing for redistribution and normalization of blood flow to each fetus.
The researchers assessed the children’s cognitive, language, behavior, and motor skills using three standard neurodevelopmental tests. The mean scores of all three tests were within or above average range or raised no concerns. They noted differences in some outcomes based on TTTS stage and whether or not a twin was a former donor versus former recipient.
“The risk of neurodevelopmental sequelae is low in TTTS with SLPC intervention,” the researchers concluded; however, Dr. Khalek suggested future research should follow neurodevelopmental outcomes as TTTS survivors reach school age.
“This data will allow us to further stratify patients and guide us in counseling parents about longer-term neurodevelopmental outcomes for their children,” Dr. Khalek said.
Laura and Adam Epstein, whose daughters, Rose and Madeline, were treated for TTTS by fetal surgeons at CHOP in 2011, and the Conway Family Foundation, a philanthropic organization run by the twins’ grandparents, provided funding for this study.
“This research is pioneering work that wouldn’t have happened without philanthropy,” Dr. Khalek said.
Dr. Khalek presented the study results at the annual meeting of the Society for Maternal-Fetal Medicine in New Orleans held Feb. 3-8.
In addition to Dr. Khalek, study authors from CHOP include Marsha Gerdes, PhD; Casey Hoffman-Craven, PhD; Anjani Villa, BS, CCRC; Okan Elci, PhD; Julie Moldenhauer, MD; Juan Martinez-Poyer, MD; and Mark P. Johnson, MD; as well as former CHOP physician Michael W. Bebbington, MD.