Methods of pushing during vaginal delivery and pelvic floor and perineal outcomes: a review

Safety of labor, Valsalva maneuver, and neuraxial anesthesia for pregnant women after decompressive craniectomy: Case series and review of the literature

Decompressive craniectomies are a neurosurgical operation aimed at normalizing intracranial pressure (ICP). Occasionally, there is delayed replacement of the skull resulting in an acquired skull defect. When managing laboring patients with an acquired skull defect there is often fear associated with traditional labor involving the Valsalva maneuver and with neuraxial anesthesia. These fears typically stem from potential ICP changes and risk of herniation. In reviewing the literature, only 15 cases are described detailing labor management after decompressive craniectomy (DC), mostly with incomplete labor histories. We aim to expand that literature by reporting two cases of safe labor with epidural anesthesia in patients with large skull defects. The first described patient underwent a cranioplasty during pregnancy because of trauma. Later, because of concerns for pre-eclampsia, induction of labor was initiated and she received neuraxial anesthesia via epidural. The patient ultimately underwent cesarean delivery 48 h after induction began due to nonreassuring fetal heart tones. The second patient underwent a cranioplasty because of infection prior to pregnancy. Once in labor, she was cleared by neurosurgery and the anesthesia team placed her epidural. She later underwent an uncomplicated standard vaginal delivery. The existing literature on labor following DC is sparse. Retrospective review of case reports can advance discussion and standardization regarding care for laboring women with a history of DC. We advocate that the Valsalva maneuver and epidural anesthesia is safe for pregnant women who are neurologically asymptomatic.

Closed- or open-glottis pushing for vaginal delivery: a planned secondary analysis of the TRAnexamic Acid for Preventing postpartum hemorrhage after vaginal delivery study

BACKGROUND

The effect on obstetrical outcomes of closed- or open-glottis pushing is uncertain among both nulliparous and parous women.

OBJECTIVE

This study aimed to assess the association between open- or closed-glottis pushing and mode of delivery after an attempted singleton vaginal birth at or near term.

STUDY DESIGN

This was an ancillary planned cohort study of the TRAAP (TRAnexamic Acid for Preventing postpartum hemorrhage after vaginal delivery) randomized controlled trial, conducted in 15 French maternity units from 2015 to 2016 that enrolled women with an attempted singleton vaginal delivery after 35 weeks' gestation. After randomization, characteristics of labor and delivery were prospectively collected, with special attention to active second-stage pushing and a specific planned questionnaire completed immediately after birth by the attending care provider. The exposure was the mode of pushing, classified into 2 groups: closed- or open-glottis. The main endpoint was operative vaginal delivery. Secondary endpoints were items of maternal morbidity, including severe perineal laceration, episiotomy, postpartum hemorrhage, duration of the second stage of labor, and a composite severe neonatal morbidity outcome. We also assessed immediate maternal satisfaction, experience of delivery, and psychological status 2 months after delivery. The associations between mode of pushing and outcome were analyzed by multivariate logistic regression to control for confounding bias, with multilevel mixed-effects analysis, and a random intercept for center.

RESULTS

Among 3041 women included in our main analysis, 2463 (81.0%) used closed-glottis pushing and 578 (19.0%) open-glottis pushing; their respective operative vaginal delivery rates were 19.1% (n=471; 95% confidence interval, 17.6-20.7) and 12.5% (n=72; 95% confidence interval, 9.9-15.4; P<.001). In an analysis stratified according to parity and after controlling for available confounders, the rate of operative vaginal delivery did not differ between the groups among nulliparous women: 28.7% (n=399) for the closed-glottis and 27.5% (n=64) for the open-glottis group (adjusted odds ratio, 0.93; 95% confidence interval, 0.65-1.33; P=.7). The operative vaginal delivery rate was significantly lower for women using open- compared with closed-glottis pushing in the parous population: 2.3% (n=8) for the open- and 6.7% (n=72) for the closed-glottis groups (adjusted odds ratio, 0.43; 95% confidence interval, 0.19-0.90; P=.03). Other maternal and neonatal outcomes did not differ between the 2 modes of pushing among either the nulliparous or parous groups.

CONCLUSION

Among nulliparous women with singleton pregnancies at term, the risk of operative vaginal birth did not differ according to mode of pushing. These results will inform shared decision-making about the mode of pushing during the second stage of labor.

Not Just Mechanical Birthing Bodies: Birthing Consciousness and Birth Reflexes

There are two concepts of neuroendocrine reflexes associated with the expulsion of the fetus through the birth canal during the second stage of birth: the Ferguson reflex and the fetus ejection reflex. These concepts are often confused with one another and treated synonymously, thus interchangeable. However, the two not only refer to different phenomena, but they also represent the birthing woman differently. The Ferguson reflex treats the birthing woman as simply a biomechanical body. In contrast, the fetus ejection reflex does not ignore women's conscious states during birth and recognizes what is currently a well-known empirical fact: The event of birth is a complex biophysical process affected by many mental, social, and environmental factors. In that, it has a connection to the phenomenon of birthing consciousness, which is the positive altered state sometimes experienced during a physiological and undisturbed childbirth. We argue that birthing consciousness and the fetus ejection reflex, made possible by reduced cortical control, are extremely helpful in promoting physiological human childbirth. Therefore, treating a woman giving birth as a biomechanical body is not only erroneous but can also lead to medical mismanagement of the second stage of physiological childbirth with associated mental and physiological consequences.

Maternal and neonatal complications during delivery according to passive versus active second stage in woman with medical conditions (ComPActSS)

Background

The incidence of serious complications during vaginal delivery with a passive second stage in women with medical conditions is unknown.

Methods

Our retrospective cohort study with matched groups (pairing 1 passive with 2 active second stage) included women who had a medical delivery plan from the high risk obstetric team at our center. The primary outcome was a composite of major maternal and neonatal complications.

Results

The primary outcome occurred in 50% (12/24) of women in the passive group versus 35.4% (17/48) (p = 0.24) in the active group. In the passive group, we observed a longer passive second stage of labor (28 vs. 8 min, p < 0.001), a tendency towards more assisted vaginal births (29.2% vs. 12.5%, p = 0.08), and more traumatic deliveries (16.7% vs. 0%, p = 0.012).

Conclusion

The higher proportion of complications in women who had a passive second stage should encourage physicians to make this recommendation only in selected cases.

Effects of different techniques during the second stage of labour on reducing perineal laceration: An overview of systematic reviews

AIM AND OBJECTIVE

To summarize the evidence on the effects of different techniques during the second stage of labour on reducing perineal laceration depending on available systematic reviews to provide optimal evidence for decision-making.

BACKGROUND

Preventing perineal laceration has been considered an important part of improving women's health. Various techniques have been used to prevent perineal laceration during the second stage of labour. However, systematic reviews evaluating the effects of different techniques on reducing perineal laceration show inconsistent results.

DESIGN

Overview of systematic reviews.

METHODS

Five English and four Chinese databases were systematically searched for relevant systematic reviews and meta-analyses published between 1 January 2016 and 31 August 2021. The quality of the included reviews was assessed by the AMSTAR 2 tool. A narrative synthesis was conducted to report the results of moderate-to-high quality systematic reviews. The overview was reported according to the PRISMA statement.

RESULTS

Eighteen reviews were included, of which four reviews had moderate-to-high methodological quality. Perineal massage and warm compresses significantly decreased the incidence of third- or fourth-degree perineal laceration (moderate-quality evidence). Hands-off technique had no impact on perineal laceration (low-to-moderate quality evidence). Ritgen's manoeuvre could reduce the incidence of first-degree perineal laceration but increase the incidence of second-degree perineal laceration (very low-quality evidence). Spontaneous pushing (low-quality evidence) and delayed pushing (moderate-quality evidence) had no impact on the incidence of third- or fourth-degree perineal laceration. Upright positions did not increase the risk of third- or fourth-degree perineal laceration (very low- to low-quality evidence) but increased the risk of second-degree perineal laceration for women without epidural analgesia (low-quality evidence).

CONCLUSIONS

Perineal massage and warm compresses could be the better choice for preventing perineal laceration in the second stage of labour.

RELEVANCE TO CLINICAL PRACTICE

Midwives and obstetricians could use perineal massage and warm compresses to prevent perineal laceration and should consider women's preferences and experience with perineal techniques.

Navigating intensive altered states of consciousness: How can the set and setting key parameters promote the science of human birth?

The subjective childbirth experience is crucial from a public health standpoint. There is a correlation between a negative childbirth experience and a poor mental state after birth, with effects that go far beyond the postpartum (PP) period. This paper offers a new approach as to how birthing experiences, and birth in general, can be navigated. The theory of set and setting proves that psychedelic experiences are shaped, first and foremost, by the mindset of an individual entering a psychedelic experience (set) and by the surroundings in which the experience happens (setting). In research on altered states of consciousness during psychedelic experiences, this theory explains how the same substance can lead to a positive and life-changing experience or to a traumatic and frightening experience. Because recent studies suggest that birthing women enter an altered state of consciousness during physiological birth ("birthing consciousness"), I suggest analyzing the typical modern birthing experience in terms of set and setting theory. I argue that the set and setting key parameters can help design, navigate, and explain many psychological and physiological elements of the human birth process. Thus, an operative conclusion that emerges from the theoretical analysis presented in this paper is that framing and characterizing the birth environment and birth preparations in terms of set and setting is a central tool that could be used to promote physiological births as well as subjective positive birthing experiences, which is currently a primary, yet unreached goal, in modern obstetrics and public health.

Vocalization during the second stage of labor to prevent perineal trauma: A randomized controlled trial

BACKGROUND AND PURPOSE

Most women suffer some degree of perineal trauma during vaginal delivery. Second stage management strategies, including vocalization, to protect the perineum have been investigated.

OBJECTIVE

To compare the frequency and degree of perineal trauma at vaginal delivery, with and without use of the vocalization maneuver during the second stage of labor.

MATERIALS AND METHODS

This is an open-label, randomized controlled trial. We conducted the study at the Center for Normal Deliveries of IMIP. We included low-risk women without prior cesarean deliveries. Women who met the inclusion criteria and signed the informed consent form were randomized to one of two groups: Group A (experimental) and Group B (control). A physical therapist encouraged women in Group A to maintain an open glottis during pushing and to emit sounds when exhaling (vocalization). Women in Group B underwent routine humanized vaginal deliveries. The outcomes of the study were perineal integrity and degree of perineal laceration. These were measured by the study team immediately after completion of the third stage of labor.

RESULTS

Women in Group A tended to have less severe perineal tear (less second and third degree lacerations) and smaller lacerations than women in group B. The vocalization maneuver reduced the risk of a perineal tear greater than 2 cm by 68% (NNT 2.2). There was no difference in other outcomes.

CONCLUSION

Encouraging women to follow a vocalization protocol coached by a physical therapist during the second stage of labor can be a helpful labor assistance technique, since this study showed that vocalization is associated with less extensive perineal tears.

CLINICAL TRIAL REGISTRATION

This study was registered on ClinicalTrials.gov (www.

CLINICALTRIAL

gov) registration number: NCT03605615.

The obstetrical dilemma hypothesis: there's life in the old dog yet

The term 'obstetrical dilemma' was coined by Washburn in 1960 to describe the trade-off between selection for a larger birth canal, permitting successful passage of a big-brained human neonate, and the smaller pelvic dimensions required for bipedal locomotion. His suggested solution to these antagonistic pressures was to give birth prematurely, explaining the unusual degree of neurological and physical immaturity, or secondary altriciality, observed in human infants. This proposed trade-off has traditionally been offered as the predominant evolutionary explanation for why human childbirth is so challenging, and inherently risky, compared to that of other primates. This perceived difficulty is likely due to the tight fit of fetal to maternal pelvic dimensions along with the convoluted shape of the birth canal and a comparatively low degree of ligamentous flexibility. Although the ideas combined under the obstetrical dilemma hypothesis originated almost a century ago, they have received renewed attention and empirical scrutiny in the last decade, with some researchers advocating complete rejection of the hypothesis and its assumptions. However, the hypothesis is complex because it presently captures several, mutually non-exclusive ideas: (i) there is an evolutionary trade-off resulting from opposing selection pressures on the pelvis; (ii) selection favouring a narrow pelvis specifically derives from bipedalism; (iii) human neonates are secondarily altricial because they are born relatively immature to ensure that they fit through the maternal bony pelvis; (iv) as a corollary to the asymmetric selection pressure for a spacious birth canal in females, humans evolved pronounced sexual dimorphism of pelvic shape. Recently, the hypothesis has been challenged on both empirical and theoretical grounds. Here, we appraise the original ideas captured under the 'obstetrical dilemma' and their subsequent evolution. We also evaluate complementary and alternative explanations for a tight fetopelvic fit and obstructed labour, including ecological factors related to nutrition and thermoregulation, constraints imposed by the stability of the pelvic floor or by maternal and fetal metabolism, the energetics of bipedalism, and variability in pelvic shape. This reveals that human childbirth is affected by a complex combination of evolutionary, ecological, and biocultural factors, which variably constrain maternal pelvic form and fetal growth. Our review demonstrates that it is unwarranted to reject the obstetrical dilemma hypothesis entirely because several of its fundamental assumptions have not been successfully discounted despite claims to the contrary. As such, the obstetrical dilemma remains a tenable hypothesis that can be used productively to guide evolutionary research.

Is directed open-glottis pushing more effective than directed closed-glottis pushing during the second stage of labor? A pragmatic randomized trial - the EOLE study

OBJECTIVE

To compare the effectiveness of directed open-glottis and directed closed-glottis pushing.

DESIGN

Pragmatic, randomised, controlled, non-blinded superiority study.

SETTINGS

Four French hospitals between July 2015 and June 2017 (2 academic hospitals and 2 general hospitals).

PARTICIPANTS

250 women in labour who had undergone standardised training in the two types of pushing with a singleton fetus in cephalic presentation at term (≥37 weeks) were included by midwives and randomised; 125 were allocated to each group. The exclusion criteria were previous caesarean birth or fetal heart rate anomaly. Participants were randomised during labour, after a cervical dilation ≥ 7 cm.

INTERVENTIONS

In the intervention group, open-glottis pushing was defined as a prolonged exhalation contracting the abdominal muscles (pulling the stomach in) to help move the fetus down the birth canal. Closed-glottis pushing was defined as Valsalva pushing.

MEASUREMENTS

The principal outcome was "effectiveness of pushing" defined as a spontaneous birth without any episiotomy, second-, third-, or fourth-degree perineal lesion. The results in our intention-to-treat analysis are reported as crude relative risks (RR) with their 95% confidence intervals. A multivariable analysis was used to take the relevant prognostic and confounding factors into account and obtain an adjusted relative risk (aRR).

FINDINGS

In our intention-to-treat analysis, most characteristics were similar across groups including epidural analgesia (>95% in each group). The mean duration of the expulsion phase was longer among the open-glottis group (24.4 min ± 17.4 vs. 18.0 min ± 15.0, p=0.002). The two groups did not appear to differ in the effectiveness of their pushing (48.0% in the open-glottis group versus 55.2% in the closed-glottis group, for an adjusted relative risk (aRR) of 0.92, 95% confidence interval (CI) 0.74-1.14) or in their risk of instrumental birth (aRR 0.97, 95%CI 0.85-1.10).

KEY CONCLUSIONS

In maternity units with a high rate of epidural analgesia, the effectiveness of the type of directed pushing does not appear to differ between the open- and closed-glottis groups.

IMPLICATIONS FOR PRACTICE

If directed pushing is necessary, women should be able to choose the type of directed pushing they prefer to use during birth. Professionals must therefore be trained in both types so that they can adequately support women as they give birth.

The dynamic change of the anteroposterior diameter of the levator hiatus under Valsalva maneuver at term and labor outcome

AIM

The aim of the present study was to evaluate the correlation between the proportional change of anteroposterior diameter (APD) of levator hiatus from rest to maximum Valsalva maneuver in nulliparous women at term and labor outcome.

METHODS

We prospectively recruited nulliparous women at term before the onset of labor. Women underwent a two-dimensional transperineal ultrasound, measuring the APD of the levator hiatus at rest and under maximum Valsalva's maneuver. APD change from rest to maximum Valsalva was described both in terms of absolute figures and proportional change. Correlation of APD change with the mode of delivery and with labor durations was assessed.

RESULTS

Overall, 486 women were included in the analysis. No significant association between change in APD and the mode of delivery. We found a significant negative correlation between change of APD from rest to Valsalva and the duration of active second stage both in terms of absolute change (Pearson's r = -0.138, P = .009) and in terms of proportional change (Pearson's r = -0.154, P = .004). Survival outcomes based on Cox-regression model showed that APD was independently associated with the duration of active second stage of labor after adjusting for epidural analgesia, maternal age and body mass index (hazard ratio, 1.008; 95% confidence interval, 1.001-1.016; P = .04) CONCLUSION: Women with higher increase of the anteroposterior diameter of the levator hiatus from rest to Valsalva have a shorter active second stage of labor.

Contraction of the levator ani muscle during Valsalva maneuver (coactivation) is associated with a longer active second stage of labor in nulliparous women undergoing induction of labor

BACKGROUND

The Valsalva maneuver is normally accompanied by relaxation of the levator ani muscle, which stretches around the presenting part, but in some women the maneuver is accompanied by levator ani muscle contraction, which is referred to as levator ani muscle coactivation. The effect of such coactivation on labor outcome in women undergoing induction of labor has not been previously assessed.

OBJECTIVE

The aim of the study was to assess the effect of levator ani muscle coactivation on labor outcome, in particular on the duration of the second and active second stage of labor, in nulliparous women undergoing induction of labor.

STUDY DESIGN

Transperineal ultrasound was used to measure the anteroposterior diameter of the levator hiatus, both at rest and at maximum Valsalva maneuver, in a group of nulliparous women undergoing induction of labor in 2 tertiary-level university hospitals. The correlation between anteroposterior diameter of the levator hiatus values and levator ani muscle coactivation with the mode of delivery and various labor durations was assessed.

RESULTS

In total, 138 women were included in the analysis. Larger anteroposterior diameter of the levator hiatus at Valsalva was associated with a shorter second stage (r = -0.230, P = .021) and active second stage (r = -0.338, P = .001) of labor. Women with levator ani muscle coactivation had a significantly longer active second stage duration (60 ± 56 vs 28 ± 16 minutes, P < .001). Cox regression analysis, adjusted for maternal age and epidural analgesia, demonstrated an independent significant correlation between levator ani muscle coactivation and a longer active second stage of labor (hazard ratio, 2.085; 95% confidence interval, 1.158-3.752; P = .014). There was no significant difference between women who underwent operative delivery (n = 46) when compared with the spontaneous vaginal delivery group (n = 92) as regards anteroposterior diameter of the levator hiatus at rest and at Valsalva maneuver, nor in the prevalence of levator ani muscle coactivation (10/46 vs 15/92; P = .49).

CONCLUSION

Levator ani coactivation is associated with a longer active second stage of labor.