Introduction

As parturient mothers confront a variety of obstacles during childbirth, the intensity of discomfort associated with labor contractions surely is one of the most difficult ones. The severity of discomfort tends to rise as labor proceeds, causing maternal tiredness and anxiety and this may impair the quality of uterine contractions. To control for pain during labor, it is recommended by the WHO to use non-pharmacological methods. One of these options is the use of a Swiss ball to help open up the pelvis. Active pelvic motions on a Swiss ball may aid parturient women by accelerating labor progression. The pelvis constantly adapts during birthing as a result of fetal station and descent. Active pelvic motions, such as anteversion, retroversion, nutation, and counter-nutation, can assist in widening the upper and lower pelvic diameters and opening the pelvis at the start of labor until the fetus reaches the perineum. These exercises and biomechanical changes are critical in achieving a rapid and comfortable childbirth. As a result, dynamic pelvic motions on a Swiss ball have the potential to aid labor and improve mother and newborn health. Therefore, this study wanted to investigate active pelvic movements during labor, using a Swiss ball, and its usefulness on maternal and neonatal outcomes.

Methods

This pragmatic RCT included pregnant women who were in the active phase of first-stage labor, which meant they had begun giving birth. The women also had to have a low-risk, full-term pregnancy, which meant no major medical issues or premature labor. Furthermore, the study only included women who were carrying a single fetus in a cephalic presentation, which means the baby’s head comes out first during birth.

The included women were randomly assigned to the intervention or control group. The intervention group used the Swiss ball and was encouraged to use it as much as possible following a protocol. The participants in the control group received usual care. They could also use the Swiss ball but were not instructed to do specific exercises or encouraged to do so.

The active pelvic movements during labor were done using a Swiss ball. The intervention in this study involves utilizing the ball to do pelvic biomechanics exercises. The pregnant women in the experimental group were encouraged to do these exercises with the Swiss ball adapted to and based on an examination of each woman’s progression through the labor state, regardless of cervical dilatation.

The exercises were adapted to the position of the baby in the planes of the birth canal.

Head of the baby reaches the pelvic inlet

Fetus Station

When the head of the baby was in the pelvic inlet, the following exercises were performed:

• The women sat on the ball on their ischium and inclined forward with their hips flexed to more than 90°. In this position they were encouraged to do the following exercises, all with the hips in abduction and external rotation:
• retroversion,
• active pelvic tilt,
• and circular hip rotations (starting at a neutral pelvis and performing pelvic retroversion)

These exercises encourage the sacroiliac joints to be opened, increasing the opening of the pelvic inlet, facilitating the counter-nutation movement of the sacrum, and encouraging the fetus to progress downwards.

Fetus Position

If the fetus was in the right or left occiput posterior, or in the right or left occiput transverse position (see image below), the following positions were held to cancel out gravity:

• On all fours, leaning or resting against the Swiss ball with the legs asymmetrically open
• Hips in abduction and external rotation

These exercises help the rotation of the fetus, encourage the sacroiliac joints to be opened, and increase the opening of the pelvic inlet, facilitating the counter-nutation movement of the sacrum.

Cervical effacement/dilatation

Exercises that were done to promote the effacement of the cervix (see image below) included:

• Retroversions
• Circular hip rotations using active 180° movements in the direction of pelvic retroversion
• To promote the dilatation of the right and left cervix, side-to-side hip movements with the hips in abduction and external rotation were encouraged

Early pushing urge

In case the birth-giving woman had an early pushing urge – that is, the urge to push downwards when the baby was still at a higher station and before reaching the 8-10cm of dilatation – she was encouraged to do the following exercises to cancel out gravity:

• on all fours, leaning against the ball, with hips in abduction and external rotation.

This position reduces the pressure of the weight of the fetus, reducing the urge to push early.

Head of the baby reaches the pelvic outlet

Fetus Station

The women sat on the ball, on their ischium, leaning forwards and with hip-knee angle > 90°.

They were encouraged to perform:

• Exercises of anteversion,
• Inclination and
• Circular hip rotations (beginning at the neutral pelvis and performing pelvic anteversion) with the hips in abduction and internal rotation.

These exercises encourage the fetus to descend and the ischium to open in the sacrum nutation movement.

It’s worth noting that the movement of gently bouncing on the ball was not included in the intervention. The researchers hypothesized that performing this exercise would put more strain on the soft tissues in the pelvic region, potentially contributing to swelling. This is because the baby’s head is already traversing the pelvic floor muscles.

Fetus Position

If the fetus was in the right or left occiput posterior, or in the right or left occiput transverse position (see image below), the following positions were held to cancel out gravity:

• On all fours, leaning on the ball and/or resting on the ball in a standing position, leaning forward from the trunk, with the lower limbs asymmetrically apart.
• Hips in abduction and external rotation. These exercises help the fetus rotate and the ischial joints to open, facilitating the movement of sacral nutation and increasing the diameter of the pelvis.

Cervical effacement/dilatation

To enhance the effacement in the anterior and posterior cervix, the following movements are recommended:

• Anteversion
• Circular hip rotation (beginning with a neutral pelvis)

To enhance the effacement in the right and left cervix, the following movements are recommended:

• Side-to-side hip movements with the hips in abduction and internal rotation

The control group only received routine care, which included monitoring signs and symptoms of labor progression and providing non-pharmacological pain management. These women were allowed to utilize the Swiss ball, but they received no special instructions. Further, they were also able to stand up, walk around, and take hot showers.

In both groups, it was tried to keep the environment as natural as possible, hence the choice of a pragmatic trial. In no way was someone in the intervention group obliged to do a certain exercise, nor was someone in the control group prohibited from doing some movements on the Swiss ball.

The outcome measures were:

• The duration of the labor’s first stage, starting from hospital admission and having at least 5cm of dilatation until 10cm of dilatation was reached. This was the primary outcome
• Pain intensity, VAS 0-10 was measured before the intervention and at 30, 60 and 90 minutes
• Maternal satisfaction, 0-10 with 0 reflecting the poorest degree of satisfaction
• The 15-item Maternal Perception of Childbirth Fatigue Questionnaire, where scores of 15-50 were classified as low fatigue and 51-75 points as high fatigue. The MCID is 7 points.
• Maternal anxiety was measured using the 18-item State-Trait Anxiety Inventory; with scores ranging from 18-72 and higher scores representing more anxiety. The MCID is 5 points.
• The 5th-minute Apgar score was registered, describing the condition of the newborn

Results

Two hundred women were included and randomly allocated to the intervention or control groups. At baseline, the women had similar characteristics.

When looking at the primary outcome, the first stage of the labor had a duration of 392 minutes in the intervention group and 571 in the control group. This means that the duration in the intervention group was reduced by 179 minutes.

Considering the secondary outcomes:

• The experimental intervention shortened the second stage of labor by 19 minutes (95% CI 13 to 25).
• The experimental intervention reduced pain intensity by 2.7 points (95% CI 2.3 to 3.0) after 30 minutes, 2.1 points (95% CI 1.8 to 2.4) at 60 minutes, and 2.0 points (95% CI 1.6 to 2.3) at 90 minutes.

• The experimental intervention reduced maternal fatigue by 18 points (95% CI: 16 to 21) on a scale of 15 to 75. This mean result and its 95% confidence interval outperformed the smallest worthwhile effect of 7 points. The experimental intervention reduced maternal anxiety by 9 points (95% CI: 8 to 11) on a scale of 18 to 72 (Table 4). This mean result and its 95% confidence interval outperformed the smallest worthwhile effect of 5 points.
• The experimental intervention lowered the chance of having a cesarean section by 14% (ARR 0.14, 95% confidence interval 0.03 to 0.25; NNT 7, 95% confidence interval 4 to 32).

• The two groups were identical in terms of the necessity for an instrumental delivery, episiotomy, the use of epidural analgesia, and cervical edema. The number of sutures used in each group was comparable. The predicted effect of oxytocin use was uncertain.
• The experimental group had the same or lower odds of perineal tears and the requirement for sutures as the control group. However, the research group had an 11% decreased incidence of vulvar swelling (ARR 0.11, 95% CI 0.03 to 0.19; NNT 99, 95% CI 5 to 31).
• In terms of women’s and support person’s satisfaction, both groups scored quite similarly. The intervention group’s satisfaction was 9.7 out of 10 (SD 0.6).
• The two groups were similar concerning the neonatal end-points

Questions and thoughts

Two Cochrane reviews by Lawrence et al., 2013 and Gupta et al., 2017 concluded that using positions of the mother’s choice could speed up the duration of giving birth by more than 1 hour. This was confirmed by the present study and the decrease in duration in this particular study even exceeded this. In the Cochrane study, freedom of movement was allowed and walking was encouraged. In this trial, the first was true but the women were also encouraged to do specific exercises adapted to the stage of delivery they were in and according to the baby’s positioning.

Women scheduled for a planned cesarean section, or receiving epidural analgesia or oxytocin were excluded. In case of difficulty remaining upright or fetal mortality, the women were also excluded from this RCT.

The proposed mechanism of action behind the faster childbirth lies, according to the authors in the movements helping the sacrum nutate and counternutate to open up the pelvis and widen the diameter of the pelvis so that the baby can descend and rotate more easily. With the hips in external rotation, it is speculated that the neurofilaments in the sacroiliac joints are loosened, resulting in pain relief. However, the source referenced was an RCT examining the effect of sacrum-perineum heat therapy on pain, and this study did not mention anything about the proposed mechanism of action.

As this was a pragmatic trial, the women were encouraged to do the exercises on the Swiss ball, but they were not forced to. Unfortunately, we have no idea how many women adopted other strategies/behaviors than those specified in the intervention group and what they consisted of.

Talk nerdy to me

The changes in the secondary outcomes (fatigue and anxiety) exceeded the MCID and are hence clinically relevant. The same was true for pain outcomes, which were 2.7 to 2 points lower than in the control group at the same time. The fact that someone with experience accompanied the women during the stressful and painful moments will likely have had positive effects on these two outcomes.

Satisfaction was assessed in the 24 hours after the childbirth. It is very likely that this is influenced by happiness and is probably influenced by the extreme feelings of happiness after birth and thus gives a bias in the positive sense.

In the evaluation of a clinical trial, one of the criteria is to check whether the intervention group and control group were treated equally, with the exemption of the intervention group procedures. For example, it would be necessary to have the same measurements at the same time. In this study, the control group was disadvantaged since they had no professional physiotherapist accompanying them throughout the labor. Even if they had been given no intervention, their presence in the intervention group compared to their absence in the control group could have made a difference. However, the authors ensured that the care in the control group was given according to the recommendations of the World Health Organization.

Compliance was reported to be 100%, which is very good, but not astonishing since these women were followed during their labor on only 1 occasion. Apart from doing the exercises as recommended, not much was asked of them. The investigators succeeded in reaching the target sample size and keeping this sample throughout the study, as no losses to follow-up occurred.

Take home messages

This study investigated active pelvic movements during labor with the use of a Swiss ball and examined the duration of the first stage of the labor. It was found that, compared to the control group, the duration of the first stage of the labor was reduced by 179 minutes. This is a large difference and this is consistent with a Cochrane review from 2013. The confidence interval is relatively narrow and the lower border does not exceed the null value, hence the effect is likely to be true and important.

Reference

Delgado A, Amorim MM, Oliveira ADAP, Souza Amorim KC, Selva MW, Silva YE, Lemos A, Katz L. Active pelvic movements on a Swiss ball reduced labour duration, pain, fatigue and anxiety in parturient women: a randomised trial. J Physiother. 2023 Nov 29:S1836-9553(23)00121-2. doi: 10.1016/j.jphys.2023.11.001. Epub ahead of print. PMID: 38036399. 

Additional references

Lawrence, A., Lewis, L., Hofmeyr, G. J., & Styles, C. (2013). Maternal positions and mobility during first stage labour. Cochrane Database of Systematic Reviews. 

Gupta, J., Sood, A., Hofmeyr, G. J., & Vogel, J. P. (2017). Position in the second stage of labour for women without epidural anaesthesia. Cochrane Database of Systematic Reviews, 2017(5). 

Taavoni S, Abdolahian S, Haghani H. Effect of sacrum-perineum heat therapy on active phase labor pain and client satisfaction: a randomized, controlled trial study. Pain Med. 2013 Sep;14(9):1301-6. doi: 10.1111/pme.12161. Epub 2013 Jun 7. PMID: 23746110.