Pediatric and Perinatal Pathology: SY21-1 CHRONIC INTERVILLOSITIS: VALUE OF ALKP MONITORING.

A 26-year-old Indian lady G2P0 presented at 33 weeks gestation complaining of itch. Liver function tests revealed an elevated alkaline phosphatase (ALKP) of 2983 U/L (normal range 20-110) which on fractionation was a placental or placental-like isoenzyme. All other investigations, including fetal ultrasound, were normal. Labour was induced at 37 weeks due to continued ALKP rise (peak level 4082 U/L). The baby and placental disc weighed 2740 g and 380 g, respectively. The ALKP level returned to normal over 8 weeks. Three years later the patient became pregnant again. The ALKP was monitored and rose to 1497 U/L. Fetal monitoring was increased. The baby was delivered at 38 weeks with evidence of IUGR (2400 g) with a placental disc weight of 356 g. Assessment of both placentas revealed moderate-massive chronic intervillositis associated with a mild chronic basal villitis and moderate chronic decidualitis. Placental tissue cultures grew no organisms. The features were those of chronic intervillositis of unknown etiology (CIUE). CIUE is a rare entity with an increased risk of poor pregnancy outcome including IUGR and stillbirth and a high recurrence rate. It is thought to be consequence of an abnormal maternal immune response to the fetal allograft. Serum ALKP can be a useful antenatal marker of CIUE to aid management.