Key words induction of labor - misoprostol - premature rupture of membranes - cesarean section
Introduction
Premature rupture of membranes (PROM) after week 37 + 0 of gestation occurs in around
8 – 10% of all births [1 ]. In around 40% of cases, regular contractions only start after more than 24 hours.
Induction of labor is indicated in the absence of contractions as it reduces maternal
and infant infection rates and may obviate the need to transfer the infant to a childrenʼs
hospital post partum. It is also associated with higher satisfaction levels and no
increase in cesarean section rates [2 ], [3 ].
A number of options are available to induce labor; medications to induce labor include
oxytocin and prostaglandins, and a balloon catheter may be used for mechanical induction.
The pharmaceutical information for prostaglandin E2 medication states that all forms
of treatment after rupture of the “chorioamniotic membrane” should proceed “with care”,
without expanding on the possible problems that could occur. Administration of the
synthetic prostaglandin E1 analog misoprostol is the most effective medication to
induce labor [4 ] – [7 ], and its use after PROM has been studied in detail [5 ], [8 ], [9 ], [10 ], [11 ], [12 ]. Although previous studies did not find higher infection rates following the use
of balloon catheters [13 ], they are not commonly used. Moreover, inducing labor with a balloon catheter is
not beneficial compared to the administration of misoprostol alone – and should therefore
not be used in this context [14 ]. As vaginal applications are generally associated with a higher risk of infection,
oral administration (misoprostol) appears to be the preferred method of administration
[15 ].
There are numerous studies on the efficacy of various procedures to induce labor,
but these studies often ignore the fact that the occurrence of PROM itself could be
a decisive factor influencing the induction of labor.
The aim of this study was therefore to investigate to what extent premature rupture
of membranes affects the induction of labor.
Material and Method
This historical cohort study analyzed the induction of labor using misoprostol in
singleton term pregnancies delivered at the University Gynecology Hospitals of Erlangen
(2011 – 2015) and Mannheim (2010 – 2013).
Inclusion and exclusion criteria
Exclusion criteria included fetal breech presentation, intrauterine fetal death, previous
cesarean section, and the presence of fetal structural or chromosomal anomalies. The
induction of labor with mechanical procedures such as balloon catheters was not included
in the analysis.
Procedure in routine clinical practice
Gestational age was determined based on the last menstrual period; presumed gestational
age was then reviewed using the crown-rump length measured in the first trimester
of pregnancy and corrected where necessary [16 ]. Induction of labor for PROM was compared with induction of labor for other indications.
Rupture of membranes was diagnosed clinically using the standard in-house guidelines
of the participating hospital or – if clinical findings were ambiguous – based on
the detection of biomarkers (e.g. insulin-like growth factor-binding protein 1 [IGFBP-1]).
Antibiotic prophylaxis with penicillin or clindamycin for patients allergic or intolerant
to penicillin was initiated at twelve hours after PROM and administered until delivery
of the infant. Prophylactic antibiotics were only administered immediately if Group
B streptococci were detected.
In the group who had labor induction for PROM, induction of labor started at 12 – 24
hours after rupture of membranes. The Bishop score was determined before inducing
labor with misoprostol. Misoprostol was administered orally. The initial dose was
50 µg, with repeat doses administered after four and eight hours in the absence of
contractions. On the second day of labor induction, oral misoprostol was increased
to 100 µg per dose, with a maximum of three administrations over a 24 hour period
and a minimum interval of four hours between each administration. On the third day,
100 µg misoprostol tablets were administered vaginally.
Outcome measures
The primary outcome measure was the cesarean section rate. Secondary outcome measures
included the induction-to-delivery interval, the number of vaginal births within 24
and 48 hours, the number of unsuccessful inductions of labor (defined as no birth
within 72 hours), the total dose of misoprostol, umbilical cord blood pH and base
excess (BE), and Apgar score at five minutes. The number of neonatal infections and
of transfers of neonates to childrenʼs hospitals and the incidence of puerperal endometritis
were also reviewed.
Statistical analysis
All statistical calculations and analyses were done with the statistical software
package SAS, Release 9.3 (SAS Institute Inc., Cary, North Carolina, USA). Absolute
and relative frequencies are shown for nominally scaled variables; nearly normally
distributed quantitative variables are presented as means and standard deviation.
The median and the two min/max values are given for ordinally scaled and quantitatively
discrete variables, instead of the mean.
χ2 -test or (if the necessary conditions were not fulfilled) Fisherʼs exact test were
used to compare nominally scaled variables between the two groups. Comparisons of
the means of two groups were done using t-test for two unpaired samples. Mann-Whitney
U-test was used for ordinally scaled or discrete quantitative variables. All tests
were 2-tailed. The results were considered significant if the p-value was less than
0.05.
For the primary outcome measure “cesarean section”, the odds ratios and associated
p-values of every potential moderating factor were determined by logistic regression
analysis. Similarly, the secondary outcome measure “induction-to-delivery interval”
was analyzed using linear regression, and the regression coefficient and p-value of
every moderating variable were calculated. Multivariate regression analysis was done
to analyze several moderating factors simultaneously. Parameters were integrated into
the respective statistical model up to a significance level of 0.05 using the option
“Selection = Forward”.
Results
A total of 17 649 births occurred in the study period; 4381 of them were induced (24.8%).
After taking the inclusion and exclusion criteria into account, 1861 cases were included
in this study ([Fig. 1 ]). Misoprostol was administered to 816 women to induce labor for PROM (PROM group)
and administered to 1045 women to induce labor for other indications (no-PROM group).
Fig. 1 Flow chart with information on the total number of births and inductions of labor
in the investigated cohort during the study period, after taking the inclusion and
exclusion criteria into account.
Demographic data
Demographic data are presented in [Table 1 ]. There were significant differences relating to various parameters between the two
groups: the women in the PROM group were older (30.7 ± 5.2 years vs. 30.1 ± 5.6, p = 0.0196)
and had a lower BMI (29.0 ± 5.3 vs. 30.5 ± 5.4, p < 0.0001). Gestational age and infant
birth weight were lower in the PROM group at delivery (276.4 ± 7.4 vs. 283.3 ± 7.4,
p < 0.0001; 3350.6 ± 417.8 vs. 3507 ± 473.2, p < 0.0001). Rates of gestational diabetes
(9.6 vs. 15.9%, p < 0.0001), hypertensive disorders of pregnancy (1.7 vs. 7.7%, p < 0.0001)
and intrauterine growth retardation/placental insufficiency (1.7 vs. 4.6%, p = 0.0006)
were lower for the women in the PROM group.
Table 1 Demographic data of the study group with premature rupture of membranes (PROM) and
the study group without premature rupture of membranes (no PROM).
PROM (n = 816)
no PROM (n = 1045)
p-value
p < 0.05 is considered statistically significant
Age (years)
30.7 ± 5.2
30.1 ± 5.6
0.0196
Maternal height (cm)
166.6 ± 6.7
166.4 ± 6.6
0.5986
Maternal weight (kg)
82.3 ± 15.0
85.0 ± 16.0
0.0002
Body mass index
29.0 ± 5.3
30.5 ± 5.4
< 0.0001
Gravidity
1 (1 – 7)
2 (1 – 14)
< 0.0001
Parity
0 (0 – 4)
0 (0 – 9)
< 0.0001
Gestational age (days)
276.4 ± 7.4
283.3 ± 7.4
< 0.0001
Birth weight (g)
3350.6 ± 417.8
3507.5 ± 473.2
< 0.0001
Bishop score
2 (0 – 6)
2 (0 – 6)
0.0095
Gestational diabetes
78 (9.6%)
166 (15.9%)
< 0.0001
Hypertensive disorders of pregnancy
14 (1.7%)
80 (7.7%)
< 0.0001
Intrauterine growth retardation. placental insufficiency
14 (1.7%)
48 (4.6%)
0.0006
Indications for the induction of labor
[Table 2 ] lists the indications for the induction of labor for the women in the no-PROM group.
The most common indications were overdue pregnancy (53.2%), gestational diabetes (10.4%),
and patientʼs request with no medical reason (8.4%).
Table 2 Indications for the induction of pregnancy if there was no premature rupture of membranes.
Indications
no PROM
CTG: cardiotocography
Overdue pregnancy
556 (53.2%)
Gestational diabetes
109 (10.4%)
Patientʼs request
88 (8.4%)
Anhydramnios, oligohydramnios
58 (5.6%)
Suspicion of fetal macrosomia
39 (3.7%)
Decreased fetal movement
20 (1.9%)
Intrauterine growth retardation, placental insufficiency, pathological Doppler sonography
36 (3.4%)
Hypertensive disorders of pregnancy (HDP)
61 (5.8%)
Suspicious/pathological CTG
28 (2.7%)
Cholestasis of pregnancy (ICP)
11 (1.1%)
Other
39 (3.7%)
Outcome measures
The outcome parameters for both groups are shown in [Table 3 ]. The cesarean section rate, i.e. the primary outcome measure, was significantly
lower for the PROM group (21.9 vs. 26.3%, p = 0.0391). Likewise, the induction-to-delivery
interval for the PROM group was shorter ( 972 ± 727 [854 – 6734] vs. 1741 ± 1335 [97 – 10 834]
min, p < 0.0001) and the rate of vaginal births within 24 hours (80.9 vs. 52.0%, p = 0.0001)
and 48 hours (98.4 vs. 85.3%, p = 0.0001) was higher. There were fewer unsuccessful
inductions when labor was induced because of PROM (0.5 vs. 5.6%, p = 0.0001). Fewer
doses of misoprostol were required in the PROM group (1 [1 – 10] vs. 3 [1 – 10], p < 0.0001)
and the total dose of misoprostol was lower (50 [50 – 750] vs. 150 µg [50 – 2500],
p < 0.0001). There were significantly fewer pathological CTG patterns (20.5 vs. 24.7%,
p = 0.0313), cases of green amniotic fluid (12.3 vs. 16.5%, p = 0.0108), and transfers
of infants to the childrenʼs hospital (13.2 vs. 18.4%, p = 0.0075) in the PROM group;
however, the rates of oxytocin administration (49.0 vs. 43.0%, p = 0.0106) and epidural
analgesia (47.1 vs. 38.0%, p < 0.0001) were higher.
Table 3 Outcome measures for the two study groups (PROM und and no PROM).
Outcome measures
PROM (n = 816)
no PROM (n = 1045)
p-value
BE: base excess
* without cesarean section and unsuccessful induction of labor
** without cesarean section
Mode of delivery (n, %)
529 (64.8%)
659 (63.1%)
0.4314
108 (13.2%)
111 (10.6%)
0.0826
179 (21.9%)
275 (26.3%)
0.0290
Induction-to-delivery interval (min)*
972 ± 726.5
1741 ± 1335.0
< 0.0001
Vaginal birth within 24 h (n, %)**
515 (80.9%)
400 (52.0%)
< 0.0001
Vaginal birth within 48 h (n, %)**
627 (98.4%)
657 (85.3%)
< 0.0001
Unsuccessful induction of labor = no vaginal birth within 72 h (n, %)**
3 (0.5%)
43 (5.6%)
< 0.0001
Number of misoprostol doses administered (median, range)*
1 (1 – 10)
3 (1 – 100)
< 0.0001
Total dose of misoprostol (µg; median, range)*
50 (50 – 750)
150 (50 – 2500)
< 0.0001
Arterial cord blood pH < 7.05 (n, %)
5 (0.6%)
8 (0.8%)
0.6936
Arterial cord blood pH < 7.10 (n, %)
21 (2.6%)
24 (2.3%)
0.7013
BE < −12 (n, %)
4 (0.5%)
13 (1.3%)
0.0872
Apgar score after 5 min (median, range)
10 (5 – 10)
10 (4 – 10)
0.1756
Apgar score after 5 min < 7 (n, %)
7 (0.9%)
8 (0.6%)
0.4689
BE < −12 and Apgar score after 5 min < 7 (n, %)
0
1 (0,1%)
1.0000
Pathological CTG (n, %)
167 (20.5%)
258 (24.7%)
0.0313
Pathological fetal blood sampling results (n, %)
3 (0.4%)
5 (0.5%)
1.0000
Epidural analgesia (n, %)
388 (47.1%)
382 (38.0%)
< 0.0001
Oxytocin (n, %)
393 (49.0%)
443 (43.0%)
0.0106
Green amniotic fluid (n, %)
100 (12.3%)
172 (16.5%)
0.0108
Amniotic infection syndrome
7 (0.9%)
6 (0.6%)
0.4659
Postpartum transfer of infant to a childrenʼs hospital (n, %)
90 (13.2%)
139 (18.4%)
0.0075
Neonatal infection (n, %)
21 (2.6%)
29 (2.8%)
0.7896
Puerperal endometritis (n, %)
2 (0.3%)
2 (0.2%)
1.0000
Outcome measures according to parity
[Table 4 ] shows the outcome measures broken down according to parity. The cesarean section
rate was lower in the PROM group for both primiparae (28.5 vs. 37.1%, p = 0.0056)
and multiparae (4.1 vs. 10.8%, p = 0.0158). The frequencies for cesarean section,
spontaneous delivery, and surgical vaginal delivery in the PROM group differed significantly
from those of the no PROM group for both primiparae and multiparae ([Table 4 ]). Similarly, the induction-to-delivery interval was shorter (1114 ± 734 [167 – 9001]
vs. 1977 ± 1379 [288 – 9001] min, p < 0.0001; 684 ± 618 [54 – 59 696] vs. 1501 ± 1245
[97 – 10 834] min, p < 0.0001), the rate of vaginal deliveries within 24 hours (75.2
vs. 42.4%, p < 0.0001; 92.4 vs. 61.7%, p < 0.0001) and 48 hours (97.9 vs. 82.8%, p < 0.0001;
99.5 vs. 87.9%, p < 0.0001) was higher, and the percentage of successful inductions
of labor was lower (0.5 vs. 8.0%, p < 0.0001; 0.5 vs. 3.1%, p = 0.0390). Misoprostol
was administered less often (1 [1 – 9] vs. 3 [1 – 10], p < 0.0001; 1 [1 – 10] vs.
3 [1 – 16], p < 0.0001) and the total dose of administered misoprostol was lower (50
[50 – 750] vs. 150 µg [50 – 2500], p < 0.0001; (50 [50 – 750] vs. 150 µg [50 – 1350],
p < 0.0001). Pathological CTG patterns (25.0 vs. 33.0%, p = 0.0020) and green amniotic
fluid (12.7 vs. 20.4%, p = 0.0003) were only lower for primiparae in the PROM group.
The epidural analgesia rate was also only significantly higher for the primiparae
in the PROM group (55.8 vs. 50.0%, p = 0.0455). The percentage of infants transferred
to a childrenʼs hospital post partum was lower for both primiparae and multiparae
(15.4 vs. 22.0%, p = 0.0085; 6.9 vs. 13.2%, p = 0.0333).
Table 4 Outcome measures in the two study groups PROM and no PROM according to parity.
Outcome measures
Primiparae
Multiparae
PROM (n = 597)
no PROM (n = 618)
p-value
PROM (n = 219)
no PROM (n = 427)
p-value
* without cesarean section and unsuccessful induction of labor
** without cesarean section
NC: non-calculable
Mode of delivery
328 (54.9%)
293 (47.4%)
0.0056
201 (91.8%)
366 (85.7%)
0.0158
99 (16.6%)
96 (15.5%)
9 (4.1%)
15 (3.5%)
170 (28.5%)
229 (37.1%)
9 (4.1%)
46 (10.8%)
Induction-to-delivery interval (min)*
1114 ± 734
1976 ± 1379
< 0.0001
684 ± 618
1501 ± 1244
< 0.0001
Vaginal birth within 24 h (n, %)**
321 (75.2%)
165 (42.4%)
< 0.0001
194 (92.4%)
235 (61.7%)
< 0.0001
Vaginal birth within 48 h (n, %)**
418 (97.9%)
322 (82.8%)
< 0.0001
209 (99.5%)
335 (87.9%)
< 0.0001
Unsuccessful induction of labor = no vaginal birth within 72 hours (n, %)**
2 (0.5%)
31 (8.0%)
< 0.0001
1 (0.5%)
12 (3.1%)
0.0390
Number of misoprostol doses (median, range)*
1 (1 – 9)
3 (1 – 100)
< 0.0001
1 (1 – 10)
3 (1 – 16)
< 0.0001
Total misoprostol dose (µg; median, range)*
50 (50 – 750)
150 (50 – 2500)
< 0.0001
50 (50 – 750)
150 (50 – 1350)
< 0.0001
Arterial cord blood pH < 7.05 (n, %)
4 (0.7%)
6 (1.0%)
0.7532
1 (0.5%)
2 (0.5%)
1.0000
Arterial cord blood pH < 7.10 (n, %)
18 (3.0%)
20 (3.2%)
0.8209
3 (1.4%)
4 (0.9%)
0.6941
BE < −12 (n, %)
4 (0.7%)
9 (1.5%)
0.1802
0
4 (1.0%)
0.3048
Apgar score after 5 min
10 (5 – 10)
10 (4 – 10)
0.0678
10 (5 – 10)
10 (7 – 10)
0.2223
Apgar score after 5 min < 7 (n, %)
6 (1.0%)
6 (1.0%)
0.9542
1 (0.5%)
0
0.3401
BE < −12 and Apgar score after 5 min < 7 (n, %)
1 (0.2%)
0
1.0000
0
0
NC
Pathological CTG (n, %)
149 (25.0%)
204 (33.0%)
0.0020
18 (8.2%)
54 (12.7%)
0.0905
Pathological fetal blood sampling results (n, %)
3 (0.5%)
5 (0.8%)
0.7260
0
0
NC
Epidural analgesia (n, %)
333 (55.8%)
304 (50.0%)
0.0455
50 (23.1%)
78 (18.4%)
0.1553
Oxytocin (n, %)
350 (59.5%)
352 (58.2%)
0.6377
43 (20.1%)
91 (21.4%)
0.6992
Green amniotic fluid (n, %)
76 (12.7%)
126 (20.4%)
0.0003
24 (11.0%)
46 (10.8%)
0.9426
Amniotic infection syndrome
6 (1.0%)
6 (1.0%)
0.9520
1 (0.5%)
0
0.3390
Postpartum transfer to a childrenʼs hospital (n, %)
78 (15.4%)
98 (22.0%)
0.0085
12 (6.9%)
41 (13.2%)
0.0333
Neonatal infection (n, %)
20 (3.4%)
20 (3.2%)
0.9115
1 (0.5%)
9 (2.1%)
0.1767
Puerperal endometritis (n, %)
2 (0.3%)
1 (0.2%)
0.6183
0
1 (0.2%)
1.0000
Amniotic infection syndrome (primiparae/multiparae: < 0.5%) and puerperal endometritis
(primiparae/multiparae: approx. 0.2%) were very rare events. Neonatal infections were
more common for primiparae compared to multiparae (40 [3.3%] vs. 10 [1.5%], p = 0.0270).
Multivariate analysis
The results of multivariate analysis for the outcome measures “cesarean section” and
“induction-to-delivery interval” are shown in [Tables 5 ] and [6 ]. As regards the cesarean section rate, it is clear that some factors which were
shown to be significant moderating factors were not included in the multiple model.
Whether the mother had PROM was one of them. The reason for not including PROM was
that other factors (e.g., gravidity and BMI) had a stronger impact, and the combination
of the five factors included in the final model were best suited to explaining the
outcome measures. Knowing whether or not the mother had PROM provided no additional
relevant information.
Table 5 Univariate and multiple logistic regression analysis for the primary outcome measure
“cesarean section”. Parameters with a significance level of up to α = 0.05 were included
in the final statistical model.
Moderating factor
Univariate analysis
Multiple logistic regression
odds ratio
p-value
odds ratio
p-value
Age (years)
1.0000
0.9646
–
–
Maternal height (cm)
0.966
< 0.0001
0.959
< 0.0001
Maternal weight (kg)
1.012
0.0003
–
–
Body mass index
1.061
< 0.0001
1.060
< 0.0001
Gestational age (days)
0.998
0.7432
–
–
Birth weight (g)
1.000
0.8639
–
–
Gravidity
0.653
< 0.0001
0.633
< 0.0001
Parity
0.413
< 0.0001
–
–
Bishop score
0.818
< 0.0001
0.852
< 0.0001
PROM
0.787 (yes vs. no)
0.0292
–
–
Gestational diabetes
1.262 (yes vs. no)
0.1303
–
–
Hypertensive disorders of pregnancy
2.783 (yes vs. no)
< 0.0001
2.063 (yes vs. no)
0.0030
Intrauterine growth retardation, placental insufficiency
2.158 (yes vs. no)
0.0037
–
–
Table 6 Univariate and multiple linear regression analysis for the secondary outcome measure
“induction-to-delivery interval”. Parameters with a significance level of up to α = 0.05
were included in the final statistical model. The binary factors PROM, gestational
diabetes, and hypertensive disorders of pregnancy had a value of 0 (no) or 1 (yes).
Moderating factor
Univariate analysis
Multiple linear regression
regression coefficient
p-value
regression coefficient
p-value
Age (years)
− 6.804
0.2513
–
–
Maternal height (cm)
3.797
0.4224
–
–
Maternal weight (kg)
12.147
< 0.0001
–
–
Body mass index
39.603
< 0.0001
21.391
< 0.0001
Gestational age (days)
23.345
< 0.0001
–
–
Birth weight (g)
0.333
< 0.0001
0.225
0.0012
Gravidity
− 90.404
0.0003
–
–
Parity
− 143.724
< 0.0001
− 213.596
< 0.0001
Bishop score
− 136.677
< 0.0001
− 111.166
< 0.0001
PROM
− 768.939
< 0.0001
− 710.722
< 0.0001
Gestational diabetes
337.895
0.0003
243.398
0.0070
Hypertensive disorders of pregnancy
842.171
0.0002
417.867
0.0102
Intrauterine growth restriction, placental insufficiency
424.003
0.0290
–
–
However, the secondary outcome measure “induction-to-delivery interval” was strongly
affected by PROM. Whether the mother had PROM or not had the greatest impact on this
secondary outcome measure compared to all other investigated factors. [Table 6 ] shows that when the mother had PROM, the induction-to-delivery interval was shorter
by an average of approximately 711 minutes (including all other factors integrated
into the final model).
Discussion
This historical cohort study showed that induction of labor for PROM is associated
with lower cesarean section rates, a shorter induction-to-delivery interval, and a
higher number of births within 24 and 48 hours compared to other indications for the
induction of labor. This finding applied to both primiparae and multiparae. In multivariate
analysis the effect of PROM was only significant for the induction-to-delivery interval.
This study used oral misoprostol. Misoprostol is the most effective medication for
inducing labor; the rate of cesarean sections after misoprostol administration is
significantly lower than, for example, after the administration of dinoprostone [4 ]. A Cochrane analysis done in 2014 found that oral misoprostol was more effective
than placebo to induce labor and resulted in fewer cesarean sections, irrespective
of whether women had PROM or not [4 ]. Park et al. reported that primiparae who received dinoprostone or oxytocin to induce
labor for PROM had higher cesarean section rates compared to women who did not have
PROM [17 ]. In their meta-analysis Wood et al. investigated whether the induction of labor
without PROM led to a higher rate of deliveries by cesarean section. In contrast to
the findings in our study presented here, they came to the conclusion that inducing
labor when membranes were intact resulted in fewer cesarean sections [18 ].
In our current study, the induction-to-delivery interval in the PROM group was significantly
shorter, even in multivariate analysis, and the rate of unsuccessful inductions (no
vaginal birth within 72 hours) was lower. This shorter interval to delivery has already
been reported in a number of earlier previous studies [2 ], [5 ], [19 ], [20 ], [21 ]. The rupture of membranes itself is a trigger for the start of childbirth [22 ], even if contractions only start more than 24 hours later in around 40% of women
[2 ].
Misoprostol can safely be used to induce labor after PROM. The rate of pathological
CTGs in the PROM group was lower, and there was no difference in the rate of invasive
procedures to investigate possible issues (e.g., fetal blood analysis). In their study,
Crane et al. also found no difference with regard to the number of fetal blood analyses
performed when misoprostol was administered for premature rupture of membranes at
term compared to the use of oxytocin [8 ].
Our study found no difference in the frequency of infant and maternal infections.
Amniotic infection syndrome and puerperal endometritis were extremely rare. There
was no difference in the rates of neonatal infection between the two groups, but neonatal
infection occurred more frequently with primiparae than multiparae. But this could
be due to the longer interval until the infant was delivered, as previous studies
have reported that a longer interval after PROM is associated with a higher risk of
maternal infection [23 ]. Moreover, vaginal administration also appears to be associated with an increased
risk of infection [24 ], and on the third day of inducing labor, misoprostol was administered vaginally.
The limitation of this study is its retrospective nature. The two comparison groups
also differed significantly from one another with regard to certain factors. But,
given the differences, these factors did not always appear to be clinically relevant.
The strengths of this study are the large number of cases, the studyʼs multicentricity,
and the uniform procedure used to induce labor with misoprostol.
This study was able to show that PROM at term has a beneficial effect on inducing
labor and results in a shorter induction-to-labor interval. When studies are carried
out to assess the efficacy of inducing labor, the information from our study should
lead to PROM being taken into account and cases with PROM excluded from the analysis.
Conclusion for Clinical Practice
Conclusion for Clinical Practice
In summary, the induction of labor with misoprostol in women with premature rupture
of membranes leads to a shorter induction-to-delivery interval compared to the induction
of labor for other indications. This impact of PROM should be taken into account when
studies are carried out to assess the efficacy of methods used to induce labor. The
use of misoprostol to induce labor for PROM is safe as it results in fewer pathological
CTGs and fewer postpartum transfers of neonates to childrenʼs hospitals, and there
is no increase in the rates of infant and maternal infection.
