Fig. 1

Clinical course, laboratory data, and treatment of the patient. Initial mPSL pulse therapy was provided for 3 days after 30 weeks and 5 days of gestation and then switched to oral PSL therapy. At 33 weeks and 0 days of gestation, another pulse therapy was provided for the second flare. EFBW was restricted gradually from − 0.6 SD to − 1.5 SD. At 36 weeks and 0 days of gestation, this patient started irregular uterine contractions and finally delivered a healthy infant spontaneously at 36 weeks and 3 days of gestation. At 12 days postpartum, she experienced the third flare, and oral PSL therapy was maintained