Extremely High Levels Of Alkaline Phosphatase And Pregnancy Outcome: Case Series And Review Of The Literature

Objectives: To evaluate the association between extremely elevated alkaline phosphatase (ALKP) levels (above 1000 U/L) and adverse perinatal outcome.Methods: A retrospective case series of all parturients with extremely elevated ALKP levels taken throughout pregnancy at a single university-affiliated medical center (2010-2018). Demographics and medical data were retrieved. Following literature review, previously reported similar cases were added to the cohort. We report perinatal outcome of our cohort as well as literature review.Results: During study period 11 parturients with high ALKP were identified. Ten more cases were retrieved from PubMed search. Overall, median ALKP levels were 1880 (range 1052-4488 U/L). Reasons for evaluation were mostly nonspecific symptoms (pruritus, headache, abdominal pain) or routine obstetrical evaluation. In 10/12 (83%) cases, elevated ALKP levels were of placental origin; the rest had osteal origin. Median gestational age at delivery was 38 (range 35-41); four (19%) women had preterm delivery. Six patients (29%) had gestational diabetes mellitus and six (29%) had hypertensive disorders. Histopathology of the placenta was available in eight cases: three normal histology (38%) and five with different non-specific pathologies.Conclusions: We report the largest case series of extremely elevated levels of ALKP in pregnancy thus far. Our data suggest association with adverse perinatal outcome.