This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
[{'content': 'True statement regarding twin delivery is: \nSelect and explain. \nA. First twin has more chances of asphyxia, B. Second twin has more chances of developing polycythemia, C. Second twin has more chances of developing hyaline membrane disease., D. Increased mortality in first twin.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Twin pregnancy in general is associated with higher incidence of perinatal morbidity and mortality.\nPerinatal mortality in twins is 5 times greater than in singleton pregnancies.\nPerinatal mortality in twins varies with birth order and the type of placentation.\n\xa0“Second twins do not do as well as the first twin…perinatal mortality being 9% for the first twin and 14% for the second twin”.\n\nFernando Arias 3/e, p 297\n\nAlso monochorionic—monoamniotic twins have a poor prognosis, perinatal mortality being 50%.\nNow with this background lets see each option separately.\n\nOption a: First twin has more chances of asphyxia—incorrect as:\n\n“Asphyxia and stillbirth are more common (in twin pregnancy) due to increased prevalence of pre-eclampsia, malpresentations, placental abruption and increased operative interferences. The second baby is more atrisk.\n\nDutta Obs. 7/e, p 206\nOption b: Second twin has more chances of developing polycythemia:\n\nThis statement can be true as second baby has more chances of asphyxia which can stimulate erythropoeisis in the second twin. Also there are chances of bleeding from the first twin into the second twin in case of monochorionic twins which can cause polycythemia.\n\nOption c: Second twin has more chances of developing hyaline membrane disease—this is incorrect as is evident from the following lines of Williams:\n\n“As measured by determination of the lecithin and sphingomyelin ratio, pulmonary maturation is usually synchronous in twins.”\n\nWilliams 23/e, p 880\n\nHence second twin does not have increased chances of developing hyaline membrane disease.\nComing to the last option—Increased mortality in first twin (option d)', 'role': 'assistant'}]