Women’s experiences of induction of labour with misoprostol tablets compared with vaginal insert

In Denmark, 24% of deliveries are induced, with a 27% prevalence among nulliparous women [1]. Hence, it is of great importance to offer a regimen of induction that is safe and cost efficient and that also provides the best possible experience for the parents.

In a recent study, we compared women induced with oral misoprostol to slow-release vaginal insert [2] finding that induction with vaginal misoprostol led to faster deliveries and an increased risk of tachysystole but with similar perinatal outcomes and incidence of Caesarean or instrumental vaginal delivery. Low-dose oral misoprostol appeared to be safe but was associated with an increased use of secondary methods of induction and a non-significant trend towards more intrapartum fever than vaginal misoprostol.

Most studies have evaluated safety and efficacy in relation to induction [3], but recently more attention has been dedicated to women’s experiences of induction of labour, suggesting that women’s experience should be an important factor in the decision-making process [4].

The aim of this study was to compare two populations of nulliparous women with unripe cervices regarding experiences of induction of labour and who gave birth after induction with oral misoprostol and slow-release vaginal insert.

METHODS

All nulliparous women with planned vaginal delivery and medical induction of labour were evaluated. The inclusion criteria were term, singleton pregnancies with cephalic presentation.

The exclusion criteria were previous uterine scar, suspicion of foetal growth restriction and prelabour rupture of membranes. Furthermore, the women needed to be able to complete the questionnaire in Danish language.

This was a prospective cohort study conducted in two different obstetric departments in the region of Zealand from November 2015 to November 2017 with telephone follow-up until May 2018.

The demographic population of women in the two departments who answered the questionnaire differed regarding BMI and pregnancy-related medical conditions (Table 1). Women with gestational diabetes mellitus (GDM) were referred to one of the departments [2].

One department (Næstved) used 25 µg oral tablets of misoprostol every two hours with a maximum of eight administrations per day. Treatment was discontinued when the woman was in active labour or after two days. Women were examined in the out-patient clinic prior to induction, and as a minimum daily.

The other department (Holbæk) used a 200 µg slow-release vaginal misoprostol insert. The vaginal insert was removable and released misoprostol at a controlled rate for up to 24 hours. The treatment was discontinued when the woman was in active labour, after 24 hours or if tachysystole occurred in combination with cardiotocography (CTG) changes. Membranes were ruptured artificially without delay when the cervical conditions were found to be favourable based on the midwife’s assessment.

The women induced with oral misoprostol were offered an out-patient setting unless a medical indication existed for admitting the woman to the obstetric department. They were told to contact the hospital when regular contractions started or if they had any other symptoms or questions. The women who were induced with vaginal misoprostol slow-release insert were hospitalised from the beginning of induction.

All participating women completed a questionnaire after delivery. Women who did not complete the questionnaire before leaving the hospital were contacted by telephone a total of three times within the following few months and invited to participate.

The main outcomes were the women's experiences and satisfaction with the method used for induction. Secondary outcomes included pain perception and experienced length of hospital stay.

The questionnaire was based on items in the Wijma Delivery Expectancy/Experience Questionnaire, which was previously validated [5, 6]. We elaborated 17 questions regarding the woman’s moods and experiences of labour induction with most answers being provided on a scale ranging from one to five. The women were also asked about their overall satisfaction with labour induction and asked to provide some additional background data (Supplementary material A04220232_-_supplementary.pdf). All questionnaires were anonymous and all women provided written or oral informed consent for collection of data for this study [2].

The study was conducted in accordance with the guidelines of the Declaration of Helsinki and approved by the Regional Ethics Committee (no. 50213), the Regional Medicines Agency and the Danish Data Protection Agency (REG-81-2015) on September 25; 2015.

The statistical analyses were performed with SPSS Statistics. Normally distributed continuous data were reported as mean (± standard deviation). Percentage calculation was based on the number of available observations. For the analysis of the questions, we combined the answers; “strongly agree” and “agree”, “disagree agree” and “strongly disagree”, as well as “very satisfied/very good” and “satisfied/good” and “dissatisfied/bad” and “very dissatisfied/very bad”. We used an independent-samples T-test comparison of parametric continuous variables and Pearson’s χ² test was used for categorical data.

We planned to include 420 women [2], but the sample size was not reached due to a smaller number of eligible women than expected during the data collection period. The period could not be expanded since the permission for one of the medications expired and a major change in electronic patient records was introduced at the hospitals.

Trial registration: The study was registered at clinicaltrials.gov ID: NCT02693587 on February 26; 2016 and on EudraCT number 2020–000366-42 on January 23; 2020 (retrospectively) registered.

RESULTS

A total of 288 women in the cohort were eligible for the study and 123 completed the questionnaire, of whom 57 were allocated to oral misoprostol and 66 to slow-release vaginal insert (Figure 1). Baseline demographics of responders in the oral misoprostol and slow-release vaginal misoprostol groups differed on several parameters, including GDM, BMI, Bishop Score and use of epidural anaesthesia. More women induced with slow-release vaginal insert delivered within 24 hours. A total of 61.4% of women induced with oral misoprostol spent more than 48 hours from induction to labour compared with 7.6% of the slow-release vaginal insert group (Table 1).

Clinical characteristics between responders and non-responders of the questionnaire were similar, except for the distribution of GDM and the time from induction to delivery, with more women with GDM being found in the non-responder group induced by oral misoprostol (Table 1). Furthermore, time from induction to delivery differed between the responder and non-responder group with more women in the responder group delivering within 24 hours. During the study period, women with GDM were referred to one department (Næstved) only. Characteristics of the two groups excluding women with GDM are presented in Table 2.

In the comparison of the oral misoprostol group and slow-release vaginal insert group, we found no significant differences regarding the women's emotions during induction, overall evaluation of the induction of labour or feelings about the labour being induced (Table 3).

We found a non-significant trend towards women being induced with slow-release vaginal insert more often reporting dissatisfaction with the duration of induction of labour with 40.9% versus 26.3% of the dissatisfied women being induced with oral misoprostol.

Significantly more women induced with oral misoprostol reported time spent at the hospital during induction and labour as “not acceptable” or ”too long”. Also, they more often reported that they could not handle the pain during induction of labour (Table 3).

Although time from induction to birth was experienced as longer and more painful by women who were induced with oral misoprostol, the overall experience of giving birth after induction was significantly more positive in this group than among women induced with slow-release vaginal insert (Table 3).

DISCUSSION

Comparing the overall experience of birth in two departments which differed in several respects, we found that that the overall birth experience was more positive in the department in which oral misoprostol was used for induction than in the department where slow-release vaginal insert was used.

To our knowledge, this is the first study comparing women’s experiences with induction of labour with oral misoprostol or slow-release misoprostol vaginal insert. The present study is not without limitations. When we initiated this study, no validated questionnaires existed on women’s experiences of induction of labour.

The Wijma Delivery Expectancy/Experience Questionnaire is the most frequently used instrument for measurement of expectations and fear of childbirth. We designed the questionnaire for the present study based on the themes raised by Wijma et al. [5]. However, it is a limitation that the adapted questionnaire was not validated.

Another limitation is that the women were asked about their experience of the whole procedure after giving birth, and not specifically about their experience with induction. The questionnaire did not include questions on preferences of induction of labour in future pregnancies – nor questions on expectations, worries about the baby or the availability and quality of care received before and during labour, which previous reports have shown are relevant domains for women’s overall labour experience [7, 8].

A recent review concluded that women’s experiences with induced labour may likely be improved by adopting a communicative and patient-centred approach [4].

This study was also subject to methodological limitations as it was neither randomised nor blinded and because it was set in two different hospitals. During the study period, all women with GDM were referred to one of the departments. Apart from GDM several differences characterised the two populations of responders, including BMI and pregnancy-related medical conditions. No adjusted estimates were calculated.

Unfortunately, the desired number of women included in this study was not reached due to logistical challenges resulting in a weaker statistical power than foreseen.

Another limitation was the difference in in- versus out-patient regimen for induction, where the women’s experience may reflect their opportunity to leave the hospital more than the method as such. Knowledge of women’s preferences in this aspect is limited [9]. Use of oral misoprostol in an outpatient setting may potentially be more comparable to spontaneous initiation of labour where women usually spend the time during the latent phase outside hospital. However, it is also possible that some women may be more anxious in the outpatient setting because of the uncertainties surrounding induction of labour and practicalities.

One final limitation is the response rate achieved in the two groups. More women in the slow-release vaginal insert group (53%) than in the oral group (46%) participated. Although no difference in demographic characteristics between responders and non-responders was found except for faster deliveries (within 24 hours) in the responding group, the difference in response rate of the groups may result in a potential risk of biased results. One obvious reason herefore may be that these women were not informed about the study prior to induction; and when they received the questionnaire immediately after delivery, they were more likely to forget or opt out of completing the questionnaire as they had just become mothers.

Previous studies investigating women’s experiences with induction achieved a response rate of 55.1% [10] and 70% [11]; the latter study informed orally and in writing about the study at least one day before admission.

In the present study, we found that time from induction to delivery had no impact on women’s birth experience or their experience with induction of labour when comparing women delivering within 24 hours with women with more than 48 hours after induction.

It seems plausible that the risk of secondary interventions increases with the time interval between initiation of induction and delivery, thereby creating more contact moments with the attending midwife, leading to a higher satisfaction with the induction.

The relative risk of hyperstimulation increased with the use of slow-release vaginal insert, as demonstrated in our recent study and reported in other studies [2, 12, 13]. Hyperstimulation may possibly affect the lalbour experience, which supports our finding that the vaginal insert group had a more negative experience of labour.

A clinical trial on oral versus vaginal misoprostol found no difference in the average interval from the first dose of misoprostol to delivery. Even so, 14% of the women in the vaginal group versus 7.5% in the oral group were dissatisfied with the use of misoprostol [14].

Other studies found no difference in labour experience or time from induction to delivery between vaginal and oral misoprostol [15].

Research on women’s experiences with a fast versus a slow delivery is sparse. Neither a fast nor a slow delivery seems to make a difference to the experience of giving birth; nor does it seem to be important for the women’s overall experience of labour and satisfaction with the procedure. Induced women might be less satisfied in general because the experience of the time of induction is not in line with the women’s expectations. Experiences differ among pregnant women. What is important for one woman may be less important for another. Clinical factors such as gestational age, BMI, parity, indication for induction and ripening of the cervix may be factors to consider when designing individual induction regimens.

CONCLUSION

In two departments, which were different in several respects, including whether vaginal or oral misoprostol was used, the experience with induction of labour in nulliparous women using oral misoprostol or vaginal inserts was comparable. Even though no adjusted estimates were calculated, we found that the labour experience was overall better among women induced with oral misoprostol in an out-patient setting. The duration from induction of labour to delivery does not seem important to birth experience.

Correspondence Karen H. Hansen. E-mail: Karen_hell_hansen@hotmail.com

Accepted 3 November 2022

Conflicts of interest none. Disclosure forms provided by the authors are available with the article at ugeskriftet.dk/dmj

References can be found with the article at ugeskriftet.dk/dmj

Cite this as Dan Med J 2023;70(2):A04220232