Interpretation
So far, in many studies, while discussing the effect of vaginal
misoprostol use on ToP in patients with a history of C/S, the second
trimester was mostly considered as reference and different gestational
weeks were taken as the limit.3, 6, 7, 10, 12 Since
the association of increased doses of misoprostol with increased risk of
complications in termination of pregnancy is known, so our study offers
the opportunity to compare the efficacy of misoprostol at low doses in
all patients below 34 weeks of gestation and its relation with history
of C/S. Accordingly, when patients with a history of C/S below 24 weeks
of gestation (G2) and above (G4) were compared among themselves, as the
total misoprostol dose (673,8 ± 457,3 µg vs 443,5 ±212,8 µg) descreased,
the duration of treatment (19,4 ±15,9 hours vs 25,3 ±12,6 hours) and
induction to labor interval (23,5 ±14,2 hours vs 31,5 ±19,9 hours)
increased and the difference between them was found significant. It has
been reported in many studies that the induction-labor time shortens as
the vaginal misoprostol dose is increased, but it is noteworthy that the
misprostol dose used in these studies is higher than the regimens in the
current study.8, 10
In the present study, although the need for transfusion (0,9% vs 2,2%)
increased as the gestational week progressed among patients with prior
C/S history below and above 24 weeks of gestation, the difference was
found not significant. In addition, admission to MICU (0,9% vs 0%)
rates were very low and similar between the two groups. In other words,
a decrease in the dose of misoprostol used does not cause a significant
change in comorbidities, although it prolongs the induction-labor time.
In a systematic review by Berghella et al discussed that the results of
patients with a prior history of C/S between 16 and 28 weeks of
gestation who underwent pregnancy termination with
misoprostol.3 In this review, the need for transfusion
was found 0,2%, but the weeks of gestation, administration route and
dose of misoprostol of the patients included in the review were highly
variable.
One of the major disadvantages of LD vaginal misoprostol therapy in ToP
cases is the need for an auxillary treatment if the current protocol
fails. The need for an auxillary treatment increases the risk of
treatment non-compliance by prolonging the period until delivery and
causing some psychological side effects for the
patient.2, 11 In the present study, >1
ToP procedure was required in 14% of patients between 24-34 weeks of
gestation and 5,8% of patients under <24 weeks of gestation.
In other words, when the entire patient group was considered, regardless
of the history of cesarean section, the highest success with the single
ToP method was found in the Gx (G1-2) group, which results were similar
to previous studies.3, 8, 13 The group in which more
than one ToP procedure is needed the least (3,7%) is the patients (G1)
without a history of cesarean section at <24 weeks of
gestation. Accordingly, in the presence of a progress with gestational
week or a history of cesarean delivery, LD vaginal misoprostol
administration may result in unsuccessful results, increasing the need
for an auxillary treatment. However, there was no evidence of increased
complications (uterine rupture or atony) when all groups were compared
among themselves. To date, the highest uterine rupture rate reported in
the literature is 11,5%, and in this study, unlikely a minimum of 1200
µg misoprostol was administered in patients with a history of two or
more C/S (14-26 weeks).12 In the systematic review
presented by Berghella et al, uterine rupture rate was reported 0,43%
in one prior history of C/S, but the doses used were highly
variable.3 In the current study, uterine rupture was
observed only in 3 cases (0,8%) below 24 weeks of gestation, and
uterine atony was observed in 2 cases (0,9%) above 24 weeks of
gestation. We think that the low complication rate in our study is
related to the misoprostol dose and dose range administered.