Management of discordant twin

Kim, Suk Young

Abstract

In twins, growth restriction is found in up to 25%, and intertwin birth weight discordance of more than 20% is frequently recorded. The discordance is usually measured as intrapair weight difference, expressed as a percentage of the larger twin's weight. Monochorionic twins represent a high-risk group for adverse pregnancy outcome. Although unequal placental sharing may lead to selective intrauterine growth restriction of one twin, unequal blood flow by placental may cause twin-to-twin transfusion syndrome (TTTS). TTTS will develop in around 15% of monochorionic twins and constitutes one of the major causes of fetal growth discordance in monochorionic twins. The two main available treatments for TTTS are laser therapy and amnioreduction. A recent randomized controlled trial provided strong evidence suggesting that laser therapy is superior to amnioreduction in term of survival and neurologic outcomes diagnosed before 26 weeks of the severe cases of TTTS. Laser photocoagulation is an anatomical correctional treatment that aims at interrupting the vascular anastomoses responsible for the hemodynamic decompensation, whereas amnioreduction is a palliative treatment that reduces the effects of the increased amniotic fluid pressure. So we must have alternative strategy to predict early sign and symptoms of TTTS and make the available referral network to management of these discordant twins.