A newborn twin with unusual chest radiograph.

A 7-day-old (term small for gestational age) newborn female, first of a twin delivery, presented to the paediatric admissions unit, with a 2-day history of coryza, cough, shortness of breath and poor feeding. The twins were born at term by normal delivery (twin 1 weighed 1.89 kg and twin 2 2.58 kg) and they did not require any resuscitation at birth. The parents were of Asian origin and were first cousins. The mother had three previous normal deliveries and the children were healthy. The pregnancy had been complicated by gestational diabetes mellitus requiring insulin treatment. There was no other major family history of note. On examination, the baby had signs of upper respiratory tract infection, tachypnoea, mild respiratory distress, a chest clear on auscultation and normal oxygen saturations in air. Systemic examination was otherwise unremarkable. The baby was admitted for observation and nasogastric feeding, with a diagnosis of acute bronchiolitis on admission. The nasopharyngeal aspirate was negative for common respiratory viruses, including respiratory syncytial virus. Full blood count showed haemoglobin 18.9 g/dl, white cells 19.5×109/l, neutrophils 8.9×109/l, lymphocytes 6.6×109/l and …