INTRODUCTION

The biomechanics of childbirth involve the complex interplay between the structure of the mother’s pelvis, the position and progress of the fetus in the birth canal, and uterine contractions. The fetus may be presented in a position that is a deviation from the optimal orientation for the delivery, where the fetus’s head is down and facing the mother’s spine. The occiput-posterior position is the most common fetal non-optimal position that occurs during labor, approximately 0.2–8% of patients deliver in this position¹. However, many non-optimal positions (>80%) identified at the onset of labor resolve as the fetus rotates into a more favorable position during the progression of labor².

Spinning Babies^® is a physiological approach³ developed by American midwife Gail Tully. It includes several exercises and techniques aimed to optimize fetal positioning throughout pregnancy and labor, which require expert guidance. It is based on three principles: balance, gravity, and movement. Balance involves maintaining optimal tension in the muscles and ligaments of the uterus to facilitate the fetus’s natural progress through the birth canal and the adjustment of head position. In cases where the baby is poorly positioned due to tight pelvic muscles, softening these muscles and ligaments can increase pelvic flexibility and help the descending. Only once balance is achieved, gravity and movement come into play and can be effective. Using gravity through maternal positioning and staying active helps to reduce pain and encourages the baby to descend lower. Being upright and mobile during labor is often more manageable than lying on hips or back in bed. Increased pelvic mobility can make it more likely that the baby will turn.

At our university teaching unit in Milan, northern Italy, the Spinning Babies^® approach was proposed to a sample of women diagnosed with a fetal non-optimal position. The aim of the current study is to compare the rate of anterior head rotation between this group and a control group which did not undergo the techniques.

METHODS

RESULTS

Of the 244 deliveries identified, 60 women underwent the Spinning Babies^® approach (mean age: 33.5 ± 4.7 years) and 184 women did not (mean age: 32.4 ± 5.1 years).

Women who underwent the Spinning Babies^® approach were more likely to be nulliparous (83.3% vs 69.0%, p=0.03) and to use analgesia (90.0% vs 62.5%, p<0.01). No differences emerged for use of oxytocin (55.7% vs 43.3%, p=0.09).

The distribution of fetal position at onset of labor and at delivery in the two groups is reported in Table 1. At the delivery, fetal head rotated from posterior (or transverse) to anterior in 93.3% (56/60) of cases of women who underwent Spinning Babies^® approach and 63.6% (117/184) of controls. The use of Spinning Babies^® techniques was associated with a 45% increased likelihood of achieving anterior positioning, with a RR of 1.45 (95% CI: 1.23–1.72), after adjusting for parity and analgesia.

DISCUSSION

The Spinning Babies^® approach appears to facilitate fetal rotation, thereby achieving optimal positioning during labor. In our sample, the majority of women who underwent these techniques achieved optimal fetal positioning by rotation (>90%), whereas approximately 65% of those who did not perform the techniques achieved fetal rotation.

Our findings were consistent with previous evidence that found a potential benefit of a set of interventions combining Spinning Babies^® approach and the Rebozo technique in reducing the likelihood of persistent occiput-posterior position⁴. Further, the literature suggests that alternative maternal positions may have a positive effect on labor, reducing maternal pain, operative vaginal delivery, cesarean section, and episiotomy rates. Women should be encouraged to move and give birth in the most comfortable position⁵.

The modified Sims position as a maternal postural intervention has been found to be effective in facilitating fetal rotation, leading to a reduction in cesarean delivery rates⁶. In a study of women who did not receive epidural anesthesia, both the semi-prone and knee-chest positions were associated with increased spontaneous rotation of the occiput to the anterior position, higher rates of vaginal delivery, and a reduction in the duration of the active phase of labor, as well as reduced post-delivery back pain⁷. However, there are conflicting results, as other authors have failed to demonstrate a significant benefit of the hands and knees position in correcting the occiput-posterior position of the fetus during the first stage of labor; however, women in the study reported an increase in comfort⁸. A systematic review and meta-analysis found that the majority of fetuses spontaneously rotate to an occiput-anterior position and suggested that maternal posture may facilitate earlier rotation but has no effect on the subset of infants who would otherwise remain in the occiput-posterior position until birth⁹. Also, the most recent Cochrane review noted a lack of evidence to guide practice regarding positional interventions for fetal non-optimal position in late pregnancy¹⁰.

In addition, a state of dynamic equilibrium within the uterine and pelvic structures must be actively maintained, highlighting the crucial role of the principle of balance³. This principle is shared by other disciplines such as osteopathy, a complementary and manual approach that uses various techniques, including myofascial techniques, to increase range of motion, improve tissue texture, reduce pain, and restore symmetry¹¹.

The head of the fetus encounters a number of obstacles as it descends, flexes and rotates in the birth canal. The position it assumes reflects the structural conformation of the mother, determined not only by the measurement of the pelvic diameters defined by the bony boundaries, but also by the tensions or poor tone of the soft tissues. From this perspective, antenatal preparation of the pelvic floor through massage¹² and training¹³ is paramount. The pelvic floor training before birth has been associated with notably lower rates of episiotomies and severe perineal trauma, as well as a higher probability of an intact perineum compared to women who received only standard care¹⁴.

Another target structure of the Spinning Babies^® approach, as of other manual approaches, is the fascia, a connective tissue that suspends, protects, and connects various structures creating a seamless connection within the human body. The fascia reorganizes itself along the lines of tension imposed or expressed in the body, in a way that can affect fascial restrictions throughout the body. This can potentially stress all the structures, both near and far, that are enveloped by the fascia itself, with consequent mechanical and physiological effects that cause misalignment with the typical position¹⁵. As regards specific techniques, the abdominal release proposed in the Spinning Babies^® program uses a very light touch to release fascial system around the pelvis and respiratory diaphragms, rebalancing the tough fascia that wraps around the sacrum. This is likely to allow the lower uterine segment to relax from tensioning the sacrum. The release of the diaphragm also helps to relax the broad ligament, which gives the baby more room to get into the right position for the birth.

CONCLUSIONS

This study suggests that the use of Spinning Babies^® approach may favor optimal fetal positioning. Further prospective studies employing standardized methodologies and objective evaluation tools are needed to confirm and expand upon these results.