Effect of Stimulating the BL67 Point on Fetal Correction from Breech to Cephalic Presentation and Natural Delivery after the 36 Weeks of Pregnancy: A Randomized Clinical Trial

Breech presentation is one of the most common indications for cesarean section (CS) in women.[1] The incidence of breech presentation is 2%-4%.[2] Factors including maternal age, early gestational age, low neonatal weight, parity, smoking during pregnancy, female neonate sex, breech and CS in previous pregnancies, diabetes, eclampsia, placenta previa, and congenital anomalies can result in breech pregnancy.[1,2,3] Various methods are proposed in different studies[4,5,6,7] in traditional medicine to correct fetus presentation. Stimulation of the BL67 point (Chinese name: Zhiyin) is a strategy assessed by some studies.[4,5,6,7] Different studies are addressing acupuncture therapy and moxibustion (Chinese stimulation) effects on BL67 points with respect to correction of breech to cephalic presentation[5,7,8,9,10] and on reducing the symptoms of mild postpartum depression with Chinese traditional medicine.[11]

The effect of BL67 point stimulation has been assessed in a study,[4] and showed that it can correct breech presentation by increasing the secretion of oxytocin from the hypophysis and change of uterine contractions. In addition, BL67 point stimulates the production of placenta estrogen and turnes it to prostaglandin and enhances the ability of the uterine contractions. Therefore, the levels of catecholamine, beta endorphins, adreno-cortico-tropic-hormone and cortisol in pregnancy become stable by decreasing the neuroendocrine response to pain. As a result, maternal metabolism, oxygen consumption and risk labor side effects are prevented and facilitated the labor progress.[12] Moreover, BL67 point stimulation increased fetal movements, reduced baseline fetal heart rate, and accelerated heart rate and fetal movement.[13] The BL67 point is a point on the small toes of the foot, located external and inferior to the nail.[5] BL67 point stimulation is a simple and low-cost intervention that can decrease the rate of CS. It has an average success rate of 58% when used after the 36 weeks of pregnancy. According to available studies, no adverse effects have been reported on mothers and fetuses. These include changes in fetal or maternal heart rate and other complications because of BL67 point stimulation.[6,13,14] However, breech presentation is a marker of abnormal pregnancy outcomes and is independently linked to an increased risk of gestational complications for mothers and neonates.[15]

Breech neonates have been linked to fetal injuries such as cerebral hemorrhage and asphyxia.[15,16,17] However, prenatal care and appropriate management of pregnancies with breech presentation can prevent adverse prenatal complications. Therefore, this study aimed to assess the effect of BL67 point stimulation on fetal correction, from breech to cephalic presentation, and the rate of vaginal delivery in pregnant women with breech presentation after the 36 weeks of pregnancy.

A parallel single blinded randomized clinical trial was conducted on 72 eligible pregnant women with breech presentations at 36 weeks of pregnancy. The subjects were recruited from counseling and midwifery clinics and health care centers in Qom, the central city in Iran, after being assessed based on inclusion and exclusion criteria. All patients signed the informed consent after being informed about the study objectives. The Ethical Committee of Qom University of Medical Sciences approved the study protocol by IR.MUQ.REC.137.1397.10 cod. In addition, the study design and intervention details were registered in the Iranian Registry Clinical Trial with the identification number IRCT20180515093671N1.

The required sample size for the study was calculated based on the results of recent studies (study power 80% and α error 5%).[18]

Based on these items, 21 was the minimum required sample size calculated for each study group. Inclusion criteria were pregnant women at 36 weeks of pregnancy with uncomplicated pregnancy, singleton pregnancy, breech presentation confirmed by routine ultrasound examination, mother’s age of >18 years, willingness to have vaginal delivery, and agreement for participation in the study. The exclusion criteria included mothers with gestational diabetes, abnormal amniotic fluid, placenta traumatic, placenta previa, umbilical cord around the neck, and unstable fetal heart rate. In addition, if the intervention time was lower 2 weeks due to emergency labor, the case was excluded.

Eligible subjects were assigned into two groups: intervention (n = 36) and control group (n = 36) by block randomization method, but in each group 32 patients were analyzed. A block size of four was considered. Selection of blocks was based on crash and was done using dice throwing. Moreover, the allocation of treatment to groups A and B was based on an accident (throwing coins). Figure 1 shows the CONSORT diagram of subject enrolments and allocation.

In the intervention group, a trained midwife conducted the training about BL67 point stimulation in pregnant women. Moreover, an educational pamphlet regarding BL67 point stimulation was provided and delivered to the intervention group. BL67 point stimulation was self-administered in mothers once a day for 2 weeks in the supine position with the knees and hips flexed. Stimulation was applied continuously for 20 min each day using a specific model and brand of plastic dressing grip (Limon Co, Iran). The intervention was conducted each weekday from the time of referral to midwifery clinic until the 38 weeks of pregnancy. All participants intervened for 2 weeks from 36^th to 38^th week of gestation and monitoring of babies checked at hospital. The fetal safety was monitored at home by the participated mothers and they were trained that they should coming to hospital if the fetal movement is reduced. Finally, the appearance of cephalic presentation was checked in the delivery room via routine ultrasound examination. There was no intervention in the control group. Also, the rate of vaginal delivery after changing presentation was compared between the two groups.

The indication of cesarean in our study was based on the Association of Scientific Medical Societies in Germany guideline including Absolute disproportion, chorioamnionitis (amniotic infection syndrome), maternal pelvic deformity, eclampsia and hellp syndrome, fetal asphyxia or fetal acidosis, umbilical cord prolapse, placenta previa, abnormal lie and presentation and uterine rupture.[19]

In total, 64 patients who were divided into two groups (n1 = n2 = 32) were analyzed in this study. The age of subjects ranged between 18 and 42 years, with a mean of 29.37 ± 5.98 years. The mean gestational age was 35.82 ± 0.98 weeks before intervention.

Table 1 shows that the two groups were statistically similar with respect to background variables, such as job (P = 0.219), parity (P = 0.399), history of breech delivery (P = 1.000), diabetes (P = 0.306), and CS history (P = 0.351). In addition, Table 2 shows that there was no statistically significant difference between groups regarding the mothers’ age (P = 0.080), weight (P = 0.347), height (P = 0.146), and BMI (P = 0.092). Nevertheless, the gestational age (39.09 ± 1.85 vs. 38.40 ± 1.26 weeks) was higher in the intervention group than in the control group (P = 0.016).

A statistical test conducted after follow-up of patients in the two groups showed that the labor duration (P = 0.774), neonatal head size (P = 0.322), neonatal Apgar score at time 1 (P = 0.341), and time 5 min (P = 0.170) was not significantly different [Table 3]. However, neonatal weight (P = 0.034) and neonatal heart rate (P = 0.044) were significantly higher in the intervention group. There was no significant difference in the neonatal gender between the two study groups (P = 0.802). Our results [Table 4 and Figure 2] show that fetal correction from breech to cephalic presentation occurred in 53.1% of patients in the intervention group and 28.1% of patients in the control group (RR = 1.88, 95% confidence interval [CI], 1.12-3.59). In addition, there was a significant difference between the two groups regarding vaginal delivery (P = 0.016) and correction of fetal presentation from breech to cephalic (P = 0.037).

Based on our results, the incidence of vaginal delivery was 34.4% in the intervention group and 9.4% in the control group (RR = 3.67, 95% CI, 1.79-5.53). CS history was reported in 13 patients (20.3%). This included 5 (7.8%) patients in the intervention group and 8 (12.5%) patients in the control group (P = 0.052). The Chi-square test revealed that the intervention increased the incidence of vaginal delivery in patients without CS history [RR = 3.26, 95% CI, 1.49-5.23] [Table 4 and Figure 2].

Logistic regression analysis was used to estimate the adjusted RR (ARR). It revealed that the intervention increased the correction of fetal presentation from breech to cephalic to 80% (ARR = 1.80, 95% CI, 1.13-5.17), and by correcting the neonatal presentation, the rate of vaginal delivery increased by >4-fold (ARR = 4.16, 95% CI, 2.54-6.82).

Complications and causes of CS section in the two groups showed that 65.6% of mothers in the intervention group and 90.6% in control group experienced CS. Repeated CS secondary to CS history was the main cause of CS in the intervention and control groups (7.8% vs. 12.5%, respectively). Rupture of membranes (ROM) occurred in five patients (15.6%) in the control group at the time of delivery. Oligohydramnios (amniotic fluid index 95 cm) occurred in one patient (3.12%), and failure to progress in dilatation (labor arrest) occurred in two patients (6.25%) in the intervention group. However, no severe adverse effects occurred in subjects during treatment [Table 4 and Figure 3]. Moreover, fetal tachycardia, preeclampsia, and postpartum hemorrhage were not reported in studied patients.

Overall, 53.1% of women with breech presentation in the intervention group had fetal correction from breech to cephalic presentation. The rate of natural delivery with uncomplicated vaginal delivery in the was 34.4%, and 40.7% in women without CS history in intervention group. A study by Brici et al. showed that BL67 point stimulation caused 62.4% correction to cephalic version in all treated women with subsequent natural vaginal delivery.[20] Another study showed that acupuncture with fire needling on the BL67 point in the intervention group resulted in a higher correction of fetal presentation than that in the control group (37.7% vs. 28.7%).[9] Moreover, a meta-analysis of six studies including 1,087 subjects showed that moxibustion creates a fetal correction of 72.5% from breech to cephalic presentation compared with that of 53.2% correction to cephalic presentation when observation or postural methods are employed in the control group.[10]

Our results show that fetal correction from breech to cephalic presentation was 1.88-fold higher in patients in intervention group than those in the control group. Moreover, the occurrence of vaginal delivery was 25% higher in the intervention group than that the control group (34.4% vs. 9.4%) and increased 3.6-fold. As demonstrated, CS history is a confounder variable, and after adjusting for its effect in the regression model, our results showed that intervention increased the rate of vaginal delivery 3.2-fold. Therefore, because of a limited number of pregnant women with CS history in this study, the effect of BL67 point stimulation on decreasing CS delivery improved. Similar results are seen in other studies, which show that BL67 point stimulation is a safe method for mothers and neonates, and it can increase fetal correction from breech to cephalic and result in vaginal delivery.[4,5,10] A study by Vas et al. showed that stimulation at acupuncture point BL67 is a safe and effective method to change the nonvertex presentation in pregnant women at 33 and 35 weeks of gestation.[7]

Our study showed that the gestational age in the intervention group was higher than that in the control group (39.09 ± 1.85 vs. 38.40 ± 1.26 weeks). Another study showed that the success rate of fetal correction from breech to cephalic increased during the 33^rd-36^th week and that this rate is higher than that in the latter weeks before delivery.[20] Therefore, it seems that BL67 point stimulation in latter gestational weeks increases the chance of fetal presentation correction and natural child birth.[20]

The ARR showed that intervention increased the correction of breech to cephalic presentation by >1.8-fold and that by correcting the fetal presentation to cephalic, the rate of CS delivery decreases 4-fold. A review study presented limited evidence to support the effect of BL67 point stimulation on fetal correction from breech presentation to cephalic. Nevertheless, it showed that BL67 point stimulation, combined with acupuncture, increases the rate of vaginal deliveries. Furthermore, BL67 point stimulation combined with postural management declined the rate of breech presentations.[5]

According to our results, no severe adverse effects occurred in the subjects during treatment. Moreover, BL67 point stimulation was not related to labor duration, change in neonatal head size, and Apgar score in treated women. The safety and effectiveness of this method were approved by other researchers.[7,14,20] However, some complications observed in the control group included ROM at the time of delivery in 15.6% patients, oligohydramnios in one patient in the control group, and labor arrest in two patients (6.25%) in the intervention group. The rate of CS was higher in the control group than that in the intervention group (65.5% vs. 90.6%). Our results show that CS history was the main cause of CS in current delivery. Based on our study, was significantly higher in intervention group than placebo group. Nevertheless, BL67 point stimulation in another study on 32 pregnant women showed that this stimulation did not affect the fetal heart rate.[14] However, a study showed a lack of uterine response after BL67 point stimulation as a significant advantage and that this method posed no risk to the fetus.[14] However, maternal age, weight, BMI, job, parity, history of breech delivery, diabetes, and CS history were the same between the two groups. Another study showed that a successful change in fetal presentation was unrelated to maternal age, nationality, and parity.[20]

This study was the first clinical trial that assessed the effect of BL67 point stimulation on the correction of the fetal position in Iran. However, the self-administrated maneuver at home was a limitation of this study because of unknown complete compliance of mothers and the monitoring of neonate presentation was difficult. The follow-up duration is limited, and it is showed in other studies[7,10] that when the intervention time increases, the success rate of fetal correction to cephalic presentation also increases. Therefore, future studies with larger sample sizes and higher intervention times are needed.

The sample size in our study was too small, and since there are many factors affecting the inversion of fetal position, future studies with larger sample size suggested.

In conclusion, BL67 point stimulation in women with breech presentation is a safe and effective method for fetal correction from breech to cephalic presentation by compliance of mothers with a self-administered procedure at home. BL67 point stimulation was unrelated to maternal and neonatal complications. In addition, correction from breech to cephalic presentation during 36-38 weeks of pregnancy increased the chance of an uncomplicated natural childbirth. Undergoing repeated CSs is not a risk factor for failure of fetal correction from breech to cephalic presentation. This method is applicable for all pregnant women after the 36 weeks of pregnancy.