Download PDF
CC BY-NC-ND 4.0 · Geburtshilfe Frauenheilkd 2025; 85(02): 210-218
DOI: 10.1055/a-2499-7897
GebFra Science
Original Article

Low-dose Oral Misoprostol after Cervical Ripening with a Double-balloon Catheter: 25 µg or 50 µg?

Article in several languages: English | deutsch
Sven Kehl 
1   Department of Obstetrics and Gynaecology, Erlangen University Hospital, Erlangen, Germany
,
Zeynep Selen Karademir
2   Department of Medical Statistics and Biomathematics, University Medical Centre Mannheim, Heidelberg University, Mannheim, Germany
,
Christel Weiss
2   Department of Medical Statistics and Biomathematics, University Medical Centre Mannheim, Heidelberg University, Mannheim, Germany
,
Adriana Titzmann
1   Department of Obstetrics and Gynaecology, Erlangen University Hospital, Erlangen, Germany
,
Michael Schneider
1   Department of Obstetrics and Gynaecology, Erlangen University Hospital, Erlangen, Germany
,
Matthias W. Beckmann
1   Department of Obstetrics and Gynaecology, Erlangen University Hospital, Erlangen, Germany
,
Simon Bader
1   Department of Obstetrics and Gynaecology, Erlangen University Hospital, Erlangen, Germany
› Author Affiliations
› Further Information
Also available at
 
 PDF Download Permissions and Reprints

Abstract

Purpose

Misoprostol is used in low doses for the induction of labor. It is still not clear, however, which of the approved doses (25 µg or 50 µg) is more beneficial. The aim of this study was to investigate whether oral misoprostol at a dose of 25 µg or at a dose of 50 µg should be preferred to induce labor after cervical ripening with a double-balloon catheter.

Material and Methods

This retrospective cohort study analyzed full-term pregnancies (≥ 37 + 0 GW) in which sequential induction of labor was carried out using a double-balloon catheter followed by oral administration of misoprostol. The patients were divided into two groups: Group 1 received 50 µg misoprostol every four hours and Group 2 received 25 µg misoprostol every two hours. The primary target parameter was the rate of caesarean sections. Secondary target parameters included the interval from induction to delivery, the rate of spontaneous births, vaginal operative deliveries, and neonatal outcomes.

Results

967 patients were included in the study: 514 in Group 1 and 453 in Group 2. There was no significant difference in the rate of caesarean sections between the two groups (p = 0.688). However, significantly more women in Group 2 had unsuccessful induction of labor, defined as a vaginal birth after 72 hours (15.8% vs. 8.1%, p = 0.001). But fewer neonates from Group 2 required transfer to the neonatal department (10.6% vs. 18.5%, p < 0.001).

Conclusion

The study found no difference in the rate of caesarean sections for the different doses of misoprostol. However the rate of vaginal deliveries only occurring after 72 hours was higher in the group treated with 25 µg misoprostol, while more neonates required transfer to the neonatal department in the group receiving 50 µg misoprostol.


#

Keywords

induction of labor - misoprostol - double-balloon cervical ripening catheter - caesarean section - neonatal outcome

Introduction

Induction of labor is now a very common obstetric measure. According to the Institute for Quality Assurance and Transparency in Healthcare (IQTIQ), 22.6% of births in Germany in 2023 were induced. Both mechanical and drug-based procedures can be used to induce labor. Today, in addition to medication, mechanical procedures such as balloon catheters for cervical ripening and induction of labor are being used more and more often [1]. According to a survey carried out in 2020, balloon catheters were used for the induction of labor in every second German obstetric clinic [2]. Balloon catheters may be used either concurrently with medication or sequentially [3] [4]. In addition to dinoprostone, misoprostol is routinely used to induce labor in Germany [2]. Misoprostol is considered to be the most effective medication for the induction of labor [5] [6] [7] and its use is recommended in different guidelines [8] [9] [10] [11]. According to a survery, in 2020 misoprostol was used in 77–89% of all German hospitals. Doses of 50 µg are administered in around 83% of all hospitals and doses of 100 µg are administered in around 50% of all hospitals [2]. In Germany, oral misoprostol has been approved for the induction of labor in doses of 25 µg und 50 µg since 2021 [12]. Both of these doses are classified as low-dose administrations [8] [13]. Although evidence is lacking that higher doses of up to 100 µg taken orally are associated with a higher risk for mother and child [6], nowadays only the lower doses are administered because of the approval modalities. It is not clear which of these lower doses should be used. Although there are some indications that the lower dose of 25 µg is associated with a longer interval from induction to delivery [14] [15], the available data is insufficient to make a final assessment. A Cochrane analysis published in 2021 only included one randomized controlled study which investigated the oral administration of 25 µg and 50 µg misoprostol [13]. Only 64 cases were included in this study which compared the oral administration of 20 ml of a misoprostol solution with a 50 µg tablet [16]. We therefore do not know whether oral administration of 25 µg misoprostol or 50 µg should be preferred.

The aim of this study was to investigate which of these low doses is more suitable for the induction of labor.


#

Material and Methods

Patient cohort

This historical cohort study was carried out in a German level 1 university perinatal center between January 2020 and December 2022. Full-term pregnancies (from 37 + 0 GW) in which sequential induction of labor was carried out using a double-balloon catheter followed by oral administration of misoprostol were included in the study. Pregnancies with primary caesarean section, elective secondary caesarean section, caesarean section in a previous pregnancy, preterm rupture of membranes, ripe cervix (Bishop score > 6) and multiple pregnancies were excluded. Additional exclusion criteria were fetal breech presentation, structural or chromosomal fetal malformations, intrauterine fetal death, and placenta previa or other contraindications for vaginal birth.

The data were collected in the context of routine clinical practice and were pseudonymized. The study was approved by the local ethics committee (no. 23–480-Br). In accordance with current recommendations, the age of gestation was determined based on the first day of the last menstruation of the woman and adapted using crown-rump length in the first trimester of pregnancy if there was a discrepancy of more than seven days [17] [18].


#

Induction method

During the investigated study period, induction of labor/cervical ripening was routinely started in the evening using a double-balloon catheter (Cook Medical, Cervical Ripening Balloon; Cook OB/GYN, Bloomington, Indiana, USA). Balloons were filled with 80 ml of liquid in accordance with manufacturer’s specifications. The Bishop score was determined and recorded before starting cervical ripening. If a rupture of membranes occurred, the balloon catheter was not removed and antibiotic prophylaxis was not initiated. No antibiotic swabs or disinfection were done beforehand. Group B Streptococci positivity (vaginal/cervical) was not an exclusion criterion to use a balloon catheter. The double-balloon catheter was removed if contractions did not start within 12 hours. The Bishop score was then determined again and induction of labor was continued with oral misoprostol.

Between January 2020 and August 2021, labor was induced with oral misoprostol at a dose of 50 µg every 4 hours for at least two days (Group 1). From September 2021 to December 2022, labor was induced with oral misoprostol at a dose of 25 µg every 2 hours for at least two days (Group 2). If labor had not started after two days, dinoprostone was administered vaginally at a dose of 1 mg and 2 mg for at least two more days. If contractions still did not start, an amniotomy was carried out (where possible) and oxytocin was administered. If there was still no progress, oxytocin administration was discontinued after 18 hours at the latest. Caesarean section was indicated in these patients because of unsuccessful induction of labor and was then carried out. Our study compares the use of oral misoprostol at a dose of 50 µg every four hours with oral misoprostol at a dose of 25 µg every 2 hours. Otherwise the approach was the same for both groups.

CTG examinations were carried out before placement of the balloon catheter and both before and after the first administration of oral misoprostol. CTG examinations were also carried out in accordance with guideline recommendations when any anomalies were present such as rupture of membranes or bleeding [9] as well as before and after every administered dose of 50 µg misoprostol. If there were no contractions and labor had not started, CTG examination was only carried out after every second administered dose of 25 µg misoprostol. Amniotomy and/or administration of oxytocin was not routinely performed during labor.


#

Statistical analysis

The primary target parameter was the caesarean section rate. The secondary target parameters included the interval from induction of labor to delivery, the rates of spontaneous births and vaginal-operative deliveries, the rate of deliveries within 24 hours and 48 hours, the rate of unsuccessful inductions of labor (defined as no birth with 72 hours) as well as the frequency of umbilical cord blood pH < 7.10, base excess < −12 mmol/l or an Apgar score at 5 minutes < 7. The rate of abnormal CTGs, whether fetal blood gas analysis was carried out, the presence of meconium in amniotic fluid, suspected triple I, placental abruption and transfer of the neonate to the neonatal department were also assessed.

Mean and standard deviation were calculated for quantitative, roughly normally distributed variables; median and range were used for skewed distribution or quantitative-discrete characteristics. Qualitative factors were presented using absolute and relative frequencies. Student’s t-test or Mann-Whitney U-test were carried out to compare the quantitative variables of two groups. Chi-square test or Fisher’s exact test were used to compare ratios. Univariable logistic regression analysis was carried out to assess the impact of different variables on a binary outcome (e.g., caesarean section). Finally, multivariable logistic analysis was done for every outcome to simultaneously analyze several influencing factors. The backward selection method was used. The odds ratio was calculated for every parameter. The level of significance was 5%. All statistical calculations were done using SAS software (SAS Institute Inc., North Carolina, USA), release 9.4.


#
#

Results

Patient cohort

At total of 967 patients were included in this study and they were divided into two groups. 514 patients received 50 µg misoprostol (Group 1) and 453 patients received 25 µg misoprostol (Group 2) for the induction of labor. The age distribution was comparable for the two groups, with a mean age of 31.8 years for Group 1 and 31.7 years for Group 2 (p = 0.689). The mean body mass index (BMI) was slightly higher in Group 1 (29.7 versus 28.1, p < 0.001). The Bishop score was also higher (median 0.5 versus 0, p < 0.001). The two groups did not differ otherwise with regards to demographic parameters. There were no differences between the groups with regard to parity, gestational age and birth weight as well as the risk factors “abnormal amniotic fluid volume,” “hypertensive disorders of pregnancy,” “fetal growth restriction,” “small-for-gestational-age fetus” (SGA fetus) or “large-for-gestational-age fetus” (LGA fetus), “gestational diabetes,” and “cholestasis of pregnancy” ([Table 1]).

Table 1 Demographic parameters.

Misoprostol 50 µg (n = 514)

Misoprostol 25 µg (n = 453)

P value

Data are presented as median (range) or mean with standard deviation, p values < 0.05 are considered significant.

Age (years)

31.8 ± 5.1

31.7 ± 5.2

0.689

Body mass index

29.7 ± 6.8
(n = 508)

28.1 ± 6.7
(n = 446)

< 0.001

Parity
median, range, mean

0 (0–6)
0.6

0 (0–7)
0.6

0.381

Gestational age (days)

280.3 ± 10.3

280.8 ± 9.3

0.415

Birth weight (grams)

3414.9 ± 577.8

3439.0 ± 573.7

0.517

Bishop score
median, range, mean

0.5 (0–6)
1.1

0 (0–5)
0.7

< 0.001

Abnormal amniotic fluid volume (oligohydramnios, polyhydramnios)

55 (10.7%)

55 (12.1%)

0.481

Hypertensive disorder of pregnancy (n, %)

84 (16.3%)

67 (14.8%)

0.507

Fetal growth restriction (n, %)

41 (8.0%)

25 (5.5%)

0.130

Small for gestational age (n, %)

59 (11.5%)

43 (9.5%)

0.316

Large for gestational age (n, %)

55 (10.7%)

54 (11.9%)

0.549

Gestational diabetes (n, %)

106 (20.6%)

81 (17.9%)

0.281

Cholestasis of pregnancy (n, %)

9 (1.8%)

12 (2.6%)

0.339

With the exception of slightly more elective inductions of labor in Group 2 (16% versus 22%, p = 0.034), there were no significant differences between the two groups.


#

Indications to induce labor

Indications to induce labor included abnormal CTG patterns (2% versus 4%, p = 0.208), diabetes mellitus/gestational diabetes mellitus (6% versus 5%, p = 0.398), fetal growth restriction (6% versus 6%, p = 0.719), HELLP syndrome (0.6% versus 0.2%, p = 0.702), hypertensive disorders of pregnancy (14% versus 13%, p = 0.616), cholestasis of pregnancy (2% versus 2%, p = 0.468), LGA fetus (7% versus 7%, p = 1.000), oligohydramnios (6% versus 7%, p = 0.621), polyhydramnios (2% versus 2%, p = 0.805), SGA fetus (10% versus 7%, p = 0.202), post-term pregnancy (27% versus 25%, p = 0.453), and other reasons (2% versus 0.9%, p = 0.505).


#

Results

The outcome parameters are shown in [Table 2]. There were no significant differences between the two groups with regards to the mode of delivery (p = 0.688). There were fewer unsuccessful inductions of labor in Group 1 (fewer vaginal births after 72 hours) compared to Group 2 (8.1% versus 15.8%, p = 0.001) but more postpartum transfers of neonates to the neonatal department (18.5% versus 10.6%, p < 0.001).

Table 2 Outcome parameters.

Outcome parameter

CRB/misoprostol 50 µg

(n = 514)

CRB/misoprostol 25 µg

(n = 453)

P value

* Caesarean sections were excluded

Spontaneous birth

390 (75.9%)

342 (75.5%)

0.688

Vaginal-operative delivery

41 (8.0%)

31 (6.8%)

Caesarean section

83 (16.1%)

80 (17.7%)

Interval from induction to delivery (min)*

1931.5
(350–9376)
(n = 420)

1906
(667–9309)
(n = 335)

0.179

Vaginal birth within 24 hours (n, %)*

115 (27.4%)
(n = 420)

83 (24.8%)
(n = 335)

0.419

Vaginal birth within 48 hours (n, %)*

302 (71.9%)
(n = 420)

237 (70.7%)
(n = 335)

0.726

Unsuccessful induction of labor (defined as vaginal birth after 72 hours; n, %)*

34 (8.1%)
(n = 420)

53 (15.8%)
(n = 335)

0.001

Arterial cord blood pH < 7.10 (n, %)

25 (4.9%)

30 (6.7%)
(n = 451)

0.232

Base excess < −12 (n, %)

22 (4.3%)

22 (4.9%)
(n = 452)

0.662

Apgar score at 5 minutes < 7 (n, %)

10 (1.9%)
(n = 513)

10 (2.1%)

0.779

Base excess < −12 and Apgar score at 5 minutes < 7 (n, %)

2 (0.4%)
(n = 513)

2 (0.4%)
(n = 452)

1.000

Abnormal CTG (n, %)

102 (19.8%)

113 (24.9%)

0.057

Fetal blood sampling (n, %)

49 (9.5%)

38 (8.4%)

0.535

Meconium in amniotic fluid (n, %)

98 (19.1%)

102 (22.5%)

0.186

Suspected triple I (n, %)

5 (1.0%)

3 (0.7%)

0.730

Transfer to neonatal department (n, %)

95 (18.5%)

48 (10.6%)

< 0.001

Placental abruption (n, %)

5 (1.0%)

0

0.064

[Table 3] shows the results of the univariable and multiple regression analyses of the primary outcome parameter “caesarean section.” Significant parameters in multiple regression analysis were parity and gestational age, gestational diabetes, and LGA fetus. The higher the gestational age, the higher the risk of caesarean section (OR 1.15, p = 0.040). The risk of caesarean section was also higher if the fetus was LGA (OR 1.91, p = 0.019) or gestational diabetes was present (OR 2.07, p < 0.001). High parity was associated with a lower risk of caesarean section (OR 0.21, p < 0.0001).

Table 3 Univariable and multiple regression analysis of the primary outcome parameter “caesarean section”.

Univariable analysis

odds ratio

Univariable p value

Multiple regression analysis

odds ratio

Multiple regression analysis

p value

Misoprostol (25 µg – 50 µg)

1.11

0.531

Body mass index (kg/m2)

1.01

0.276

Age (years)

1.01

0.679

Parity

0.22

< 0.001

0.21

< 0.001

Bishop score

0.80

0.005

Gestational age (GW)

1.14

0.039

1.15

0.040

Birth weight (kg)

0.95

0.723

Abnormal amniotic fluid volume

1.27

0.350

Gestational diabetes

1.71

0.007

2.07

< 0.001

Hypertensive disorder of pregnancy

1.09

0.714

Fetal growth restriction

0.99

0.966

Small for gestational age

0.84

0.540

Large for gestational age

1.37

0.209

1.91

0.019

Cholestasis of pregnancy

0.51

0.557

The impact on the interval between induction of labor and delivery is presented in [Table 4]. A higher BMI (OR 1.05, p < 0.001) was associated with a longer interval between induction of labor and delivery (> 48 hours) as was LGA fetus (OR 2.73, p < 0.001) and hypertensive disorder of pregnancy (OR 2.27, p < 0.001). Higher parity reduced the risk of a longer interval between induction of labor and delivery (OR 0.52, p < 0.001).

Table 4 Univariable and multiple regression analysis of the primary outcome parameter “interval from induction of labor to delivery” (normal = 48 hours).

Univariable analysis

odds ratio

Univariable p value

Multiple regression analysis

odds ratio

Multiple regression analysis

p value

Misoprostol (25 µg – 50 µg)

1.06

0.726

Body mass index (kg/m2)

1.06

< 0.001

1.05

< 0.001

Age (years)

0.98

0.168

Parity

0.56

< 0.001

0.52

< 0.001

Bishop score

0.87

0.029

Gestational age (GW)

0.94

0.253

Birth weight (kg)

1.38

0.031

Abnormal amniotic fluid volume

0.73

0.248

Gestational diabetes

1.29

0.209

Hypertensive disorder of pregnancy

2.71

< 0.001

2.27

< 0.001

Fetal growth restriction

0.53

0.105

Small for gestational age

0.68

0.158

Large for gestational age

2.12

0.002

2.73

< 0.001

Cholestasis of pregnancy

0.53

0.421

The risk factors for transfer of the neonate to a neonatal department according to univariable and multiple regression analysis are shown in [Table 5]. The administration of misoprostol at a dose of 25 µg (OR 0.53, p = 0.001), a higher gestational age (OR 0.86, p = 0.040), and a higher birth weight (OR 0.52, p = 0.006) reduced the risk of a transfer to the neonatal department.

Table 5 Univariable and multiple regression analysis of the primary outcome parameter “transfer to the neonatal department”.

Univariable analysis

odds ratio

Univariable p value

Multiple regression analysis

odds ratio

Multiple regression analysis

p value

Misoprostol (25 µg – 50 µg)

0.52

< 0.001

0.53

0.001

Body mass index (kg/m2)

0.93

0.615

Age (years)

1.02

0.265

Parity

0.83

0.097

Bishop score

0.89

0.124

Gestational age (GW)

0.74

< 0.001

0.86

0.040

Birth weight (kg)

0.41

< 0.001

0.52

< 0.001

Abnormal amniotic fluid volume

1.15

0.621

Gestational diabetes

1.50

0.056

Hypertensive disorder of pregnancy

1.62

0.031

Fetal growth restriction

2.75

< 0.001

Small for gestational age

1.58

0.081

Large for gestational age

0.76

0.372

Cholestasis of pregnancy

0.60

0.756

The parameters of the infants transferred to the neonatal department postpartum did not differ between groups ([Table 6]).

Table 6 Cases of postnatal transfer to the neonatal department.

Parameter

CRB/misoprostol 50 µg

(n = 95)

CRB/misoprostol 25 µg

(n = 48)

P value

Spontaneous birth

60 (63%)

22 (46%)

0.133

Vaginal-operative delivery

8 (8%)

5 (10%)

Caesarean section

27 (28%)

21 (44%)

Umbilical cord blood pH < 7.10 (n, %)

11 (12%)

8 (17%)

0.370

Base excess < −12 (n, %)

10 (11%)

6 (12%)

0.724

Apgar score at 5 minutes < 7 (n, %)

7 (7%)

7 (15%)

0.234

Base excess < −12 and Apgar score at 5 minutes < 7 (n, %)

2 (2%)

1 (2%)

1.000

Abnormal CTG (n, %)

31 (33%)

20 (42%)

0.287

Meconium in amniotic fluid (n, %)

24 (25%)

18 (37%)

0.129

Suspected triple I (n, %)

2 (2%)

0

0.551

Placental abruption (n, %)

2 (2%)

0

0.551

Hypertensive disorder of pregnancy (n, %)

22 (23%)

9 (19%)

0.546

Fetal growth restriction (n, %)

14 (15%)

6 (12%)

0.716

Small for gestational age (n, %)

14 (15%)

7 (15%)

0.981

Large for gestational age (n, %)

8 (8%)

5 (10%)

0.761

Gestational diabetes (n, %)

25 (26%)

11 (23%)

0.658

#
#

Discussion

This historical cohort study compared two different doses of misoprostol, a synthetic analogue of the prostaglandin E1, in the context of sequential induction of labor following cervical ripening with a balloon catheter. The investigated doses were low doses of either 50 µg or 25 µg [8] [13], both of which have been approved for the induction of labor in Germany [12]. The two patient cohorts studied from 2020 to 2022 are comparable. Although there were statistically significant differences with regards to mean BMI (29.7 versus 28.1, p < 0.001) and median Bishop score (0.5 versus 0, p < 0.001), these differences were not clinically relevant. The statistical evaluation showed that the administration of 50 µg resulted in fewer unsuccessful inductions of labor (defined as vaginal births after 72 hours) compared to 25 µg (8.1% versus 15.8%, p = 0.001). Moreover, despite the higher dose of 50 µg, the rate of abnormal CTGs tended to be slightly lower (19.8% versus 24.9%, p = 0.057). However, the rate of neonates requiring transfer to the neonatal department was higher (18.5% versus 10.6%, p < 0.001).

There is no evidence-based data from high-quality randomized controlled studies on which of the two low doses should be used for oral administration to induce labor [13]. A small study in Thailand compared a liquid containing 20 ml misoprostol with a tablet containing 50 µg misoprostol [16]. The group given the tablets received a lower overall dose of misoprostol and had fewer cases with uterine tachysystole. There were no other differences with regards to other factors such as the rate of caesarean sections.

Our study also found no differences between the two dosages with regards to the rate of caesarean sections (p = 0.5308). A meta-analysis which compared misoprostol dosages of < 50 µg with dosages of ≥ 50 µg also found that the difference in dosages did not affect the rate of caesarean sections (OR 0.69, 95% CI: 0.4–1.1) [6].

Multiple regression analysis of the primary outcome parameter “caesarean section” found that the independent risk factors for caesarean section were gestational age (p = 0.040), gestational diabetes (p < 0.001), and LGA fetus (p = 0.019). These risk factors have also been reported in other publications [19] [20]. High parity and no prior history of caesarean section reduces the risk of caesarean section, and this is well known [21]. The misoprostol dosage (25 µg or 50 µg) has no influence on this (p = 0.531). A meta-analysis which compared misoprostol dosages of < 50 µg with dosages of ≥ 50 µg also found no differences (OR 0.69, 95% CI: 0.4–1.1) [6].

While the interval between the start of induction and vaginal delivery did not differ statistically (1932 min versus 1906 min, p = 0.179), there were more unsuccessful inductions of labor (vaginal delivery only after 72 hours) when labor was induced by administering 25 µg misoprostol (8.1% versus 15.8%, p = 0.001). Multivariable regression analysis of the outcome parameter “interval between induction and birth after 48 hours” found that the independent risk factors were again BMI (p < 0.001), hypertensive disorders of pregnancy (p < 0.001), and LGA fetus (p < 0.001). The interval between induction and delivery tended to be shorter in cases with high parity (p < 0.001). This is also well known from other studies [13] [22] [23] [24]. In our study, the oral dose of misoprostol had no impact (p = 0.726).

There were fewer transfers of infants to the neonatal department when misoprostol was administered at a dose of 25 µg (18.5% versus 10.6%, p < 0.001). This reduced risk was also detectable with multivariable regression analysis (OR 0.53, p = 0.001). We found no clinical explanation for this difference. There were no changes in clinical management during the investigated period. In addition, the older the gestational age (OR 0.86, p = 0.040) and the heavier the birth weight of the infant (OR 0.52, p < 0.001), the lower the risk of needing to be transferred to the neonatal department. However, according to a very large systematic review and meta-analysis, there was no difference in the rate of transfers to a neonatal department when oral misoprostol was administered at doses of < 50 µg and at doses of ≥ 50 µg (OR 1.21, 95% CI: 0.54–2.4) [6].

Although the data on oral administration is not adequate, there is sufficient data on vaginal applications. The meta-analysis of McMaster et al. compared vaginal applications of misoprostol for the doses 50 µg and 25 µg [14]. The higher dose was found to be more effective but the rates of overstimulation, caesarean section, and transfers to the neonatal department were also higher. An older review reported similar findings: vaginal applications of 50 µg misoprostol tablets were more effective (shorter intervals between induction and delivery, more births within 24 hours, and fewer labor augmentations with oxytocin) but there were also slightly more cases with uterine tachysystole and overstimulation [15]. There was no difference in neonatal outcomes.

The current study provides important findings for clinical practice. The advantages of this historical cohort study are the large number of analyzed cases and the fact that clinical processes were consistent over the entire time of the study, which increases the comparability of results. In addition, the study closes an important gap as previously there was only limited evidence on this issue. The disadvantages are the lack of randomized allocation which, due to the different time periods in which the two groups were treated, could lead to systematic bias, and the limited control of all potentially disruptive factors (although an attempt was made to control for their impact using multivariable regression analysis). Future research should continue to focus on investigating the oral administration of misoprostol, especially in high-risk groups such as women with obesity and gestational diabetes [25]. In these cases, higher doses (e.g., 100 µg) could be effective to avoid unsuccessful induction of labor and the need for a caesarean section.


#

Conclusion

No specific benefit with regards to the rate of caesarean sections could be demonstrated for low-dose oral administration of 25 µg or 50 µg misoprostol after cervical ripening with a balloon catheter. The administration of 50 µg misoprostol resulted in fewer vaginal births after 72 hours but was associated with higher transfer rates of neonates to the neonatal department.


#
#

Conflict of Interest

The authors declare that they have no conflict of interest.


Correspondence

Prof. Dr. Sven Kehl
Department of Obstetrics and Gynaecology, Erlangen University Hospital
Universitätsstr. 21–23
91054 Erlangen
Germany   

Publication History

Received: 22 August 2024

Accepted after revision: 08 December 2024

Article published online:
06 February 2025

© 2025. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial-License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).

Georg Thieme Verlag KG
Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany


   Permissions and Reprints