INTRODUCTION:: The porphyrias are a group of rare disorders caused by deficiencies in enzymes of heme biosynthesis. Our objective is to determine the rate of acute attacks in pregnant patients with acute porphyria and risk of preterm birth. METHODS:: PubMed, EMBASE and ScienceDirect were screened from the inception of the databases to May 2019 resulting in 872 articles. Our primary outcome was rate of acute attacks during pregnancy and postpartum period manifesting with severe abdominal pain, neurological dysfunction and psychiatric disturbances in women with acute porphyria. Secondary outcome was the rate of preterm delivery. The Meta-analysis of Observational Studies in Epidemiology guidelines was used (MOOSE). RESULTS:: We identified 49 case reports with a total of 59 patients. Mean maternal age was 26.7 (±5.6) years. Mean gestational age at presentation was 19 weeks. Positive urine porphobilinogen was used to diagnose 84.8% (39/46) of women. During pregnancy 71.2% of women (42/59) suffered an acute attack. The clinical spectrum of attacks were: neurologic 52% (26/59), abdominal pain 49.2% (29/59), and psychiatric 22% (13/59). Preterm delivery occurred in 29% (9/31) of women (range 30-36 weeks). The mean gestational age at delivery was 35 weeks 6 days (±32 days) with a mean birth weight of 2705.9 (±721.5) grams. Cesarean section occurred in 45.5% of women (20/44). Hematin (or Hemin) was used in only nine patients (15.3%) without complication. CONCLUSION:: The results of our systematic review demonstrate the increased rate of acute attacks in patients with porphyria in pregnancy with nearly one third having preterm delivery.