YK Ng, P Ip, BCC Lam

From 1994-1996, there were nine cases of hydrops fetalis delivered at Tsan Yuk Hospital. Four babies were due to immune-haemolytic anaemia, four babies were idiopathic non-immune hydrops, while one baby had anaemia and congenital emphysema The male:female ratio was 4:5. Eight babies were noted to be hydropic antenatally and diagnostic procedures were performed. Five babies were treated antenatally with intra-uterine intravascular transfusion (2) and insertion of pleural-amniotic drains (3). The mean gestation age was 32.6 weeks (range 30-36). Eight babies were delivered by the abdominal route and one was delivered vaginally. Seven babies were severely asphyxiated and two were moderately asphyxiated. The mean birth weight was 2368.9 g (range 1590-4370), the mean placental weight was 867.8 g (range 520-1100) and the mean placenta: birth weight ratio was 0.404 (range 0.21-0.61). For the group with haemolytic anaemia, the mean Hb was 3.5 g/dl (range 2.4-5.0) at presentation; all responded well to exchange transfusion or packed cell transfusion. Three required mechanical ventilation but all were discharged home well. The mean haemoglobin of the idiopathic non-immune hydrops was 17.7 g/dl (range 14.7-21.0). They were all associated with hydrothoraces and all required chest drain insertion in the post-natal period. Three babies died on their first day, the post-mortem examination showed hypoplastic lungs. Two babies with intra-uterine pleural-amniotic shunt showed inflammatory and fibrotic changes of the pleura. Meconium-stained amniotic fluid in the pleural cavity suggested reflux of amniotic fluid through the pleural-amniotic shunt. The survivor required prolonged ventilation of 28 days because of hypoplastic lungs. For the baby with double pathology of fetal anaemia and congenital emphysema, the anaemia was related to maternal anti-M antibody and the emphysematous lobe of lung required surgical resection. He was ventilated for 80 days and was discharged home, but he died at 2 years because of chest complications. In summary, Rhesus isoimmunization, although rare in southern Chinese, accounts for 22.2%; while non-immune hydrops accounts for 44.4%. With effective antenatal screening of haemoglobin Bart disease, the incidence of hydrops fetalis is decreasing. Antenatal intervention in the form of intravascular transfusion was shown to be effective in improving the fetal outcome. The benefit of the intrauterine insertion of a pleuralamniotic shunt was not well shown.