Study design and patient selection
The current study was designed retrospectively between January 1, 2019 and December 31, 2021 in a single tertiary center. A five-hundred-sixty-three pregnant women who decided to terminate pregnancy were included in the study. This study was undertaken with the Institutional Review Board’s approval (Approval number: 1105085). All of the patients included in the study were below the 34th gestational week and were evaluated by dividing them into four groups. Group 1 (G1) consists of patients below 23 6/7 weeks of gestation without a prior cesarean section (C/S), and group 2 (G2) consists of patients below 23 6/7 weeks of gestation with at least one prior C/S. Group 3 (G3) consists of patients between 24-34 weeks of gestation without a prior C/S, and group 4 (G4) consists of patients between 24-34 weeks of gestation with at least one prior C/S. Gx and Gy refer to G1-2 and G3-4, respectively (Table 2 and 3).
Among the dates specified in the study, cases with a fetal anomaly incompatible with life (prenatally diagnosed with aneuploidy, microdeletion/duplication syndromes, severe or lethal fetal structural anomalies diagnosed with ultrasound were included), cases who were below 34 weeks of gestation and whose pregnancy was terminated due to intrauterine demise (IUD), missed abortion or other reasons (preterm premature rupture of membranes below 22 weeks of gestation) were included. The cases at 34 weeks of gestation and above, the cases with a history of non-C/S uterine surgery, pregnancies terminated by methods other than vaginal misoprostol as a first-line treatment, the cases with contraindication for misoprostol use and the cases who underwent elective hysterotomy as a first-line treatment due to prior C/S history were excluded from the study. In all cases above 22 0/7 weeks of gestation, feticide with fetal intracardiac KCl injection was administered before termination of pregnancy (ToP). All of the patients was followed up to the hospital as inpatient and discharged after 24 hours if vaginal delivery had been occured and 48 hours if elective hysterotomy had done. Before start of treatment, treatment-related informed consent was obtained from all patients.
The treatment protocol was defined as follows in cases which ToP is planned: In patients without a history of prior (C/S) below 23 6/7 weeks of gestation, 400 mcg misoprostol vaginally was given as a loading dose, the subsequent doses were given 200 mcg vaginally in every 4 hours, a maximum dose is 1400 mcg (G1). Above 24 0/7 weeks of gestation, 200 mcg misoprostol vaginally was administered as a loading dose, the subsequent vaginal doses are administered as 100 mcg in every 4 hours, a maximum dose is 700 mcg (G3). If the patient has at least one or more prior C/S history, the doses which are previously described were halved below (G2) and above the 24th gestational week (G4) (a maximum dose is 700 mcg and 350 mcg, respectively). When the abortion or delivery did not occur after first regimen, patients were rested for 12 hours and the same regimen was repeated once more. When a method used after the second failured (vaginal misoprostol regimen, this was named as more than one (>1) ToP procedure. Sublingual misoprostol administration, cervical ripening balloon or oxytocin induction were chosen based on cervical assesment in cases where vaginal delivery/abortion did not occur following the second failured vaginal misoprostol regimen. If there was a prior C/S history, hysterotomy was discussed with the patient after two failured vaginal misoprostol regimens. The primary outcome was the success rate of ToP by vaginal delivery after two LD vaginal misoprostol regimen (single method). None of the patients in the current study had a contraindication for prostaglandin use.