Hands-and-knees posturing and fetal occiput anterior position: a systematic review and meta-analysis

Impact of maternal posture on fetal physiology in human pregnancy: a narrative review

In numerous medical conditions, including pregnancy, gravity and posture interact to impact physiology and pathophysiology. Recent investigations, for example, pertaining to maternal sleeping posture during the third trimester and possible impact on fetal growth and stillbirth risk highlight the importance and potential clinical implications of the subject. In this review, we provide an extensive discussion of the impact of maternal posture on fetal physiology from conception to the postpartum period in human pregnancy. We conducted a systematic literature search of the MEDLINE database and identified 242 studies from 1991 through 2021, inclusive, that met our inclusion criteria. Herein, we provide a synthesis of the resulting literature. In the first section of the review, we group the results by the impact of maternal posture at rest on the cervix, uterus, placenta, umbilical cord, amniotic fluid, and fetus. In the second section of the review, we address the impact on fetal-related outcomes of maternal posture during various maternal activities (e.g., sleep, work, exercise), medical procedures (e.g., fertility, imaging, surgery), and labor and birth. We present the published literature, highlight gaps and discrepancies, and suggest future research opportunities and clinical practice changes. In sum, we anticipate that this review will shed light on the impact of maternal posture on fetal physiology in a manner that lends utility to researchers and clinicians who are working to improve maternal, fetal, and child health.

Maternal postures for fetal malposition in labour for improving the health of mothers and their infants

BACKGROUND

Fetal malposition (occipito-posterior and persistent occipito-transverse) in labour is associated with adverse maternal and infant outcomes. Whether use of maternal postures can improve these outcomes is unclear. This Cochrane Review of maternal posture in labour is one of two new reviews replacing a 2007 review of maternal postures in pregnancy and labour.

OBJECTIVES

To assess the effect of specified maternal postures for women with fetal malposition in labour on maternal and infant morbidity compared to other postures.  SEARCH METHODS: We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (13 July 2021), and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) or cluster-RCTs conducted among labouring women with a fetal malposition confirmed by ultrasound or clinical examination, comparing a specified maternal posture with another posture. Quasi-RCTs and cross-over trials were not eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, risk of bias, and performed data extraction. We used mean difference (MD) for continuous variables, and risk ratios (RRs) for dichotomous variables, with 95% confidence intervals (CIs). We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included eight eligible studies with 1766 women.  All studies reported some form of random sequence generation but were at high risk of performance bias due to lack of blinding. There was a high risk of selection bias in one study, detection bias in two studies, attrition bias in two studies, and reporting bias in two studies. Hands and knees The use of hands and knees posture may have little to no effect on operative birth (average RR 1.14, 95% CI 0.87 to 1.50; 3 trials, 721 women; low-certainty evidence) and caesarean section (RR 1.34, 95% CI 0.96 to 1.87; 3 trials, 721 women; low-certainty evidence) but the evidence is uncertain; and very uncertain for epidural use (average RR 0.74, 95% CI 0.41 to 1.31; 2 trials, 282 women; very low-certainty evidence), instrumental vaginal birth (average RR 1.04, 95% CI 0.57 to 1.90; 3 trials, 721 women; very low-certainty evidence), severe perineal tears (average RR 0.88, 95% CI 0.03 to 22.30; 2 trials, 586 women; very low-certainty evidence), maternal satisfaction (average RR 1.02, 95% CI 0.68 to 1.54; 3 trials, 350 women; very low-certainty evidence), and Apgar scores less than seven at five minutes (RR 0.71, 95% CI 0.21 to 2.34; 2 trials, 586 babies; very low-certainty evidence).  No data were reported for the hands and knees comparisons for postpartum haemorrhage, serious neonatal morbidity, death (stillbirth or death of liveborn infant), admission to neonatal intensive care, neonatal encephalopathy, need for respiratory support, and neonatal jaundice requiring phototherapy.  Lateral postures The use of lateral postures may have little to no effect on reducing operative birth (average RR 0.72, 95% CI 0.43 to 1.19; 4 trials, 871 women; low-certainty evidence), caesarean section (average RR 0.78, 95% CI 0.44 to 1.39; 4 trials, 871 women; low-certainty evidence), instrumental vaginal birth (average RR 0.73, 95% CI 0.39 to 1.36; 4 trials, 871 women; low-certainty evidence), and maternal satisfaction (RR 0.96, 95% CI 0.84 to 1.09; 2 trials, 451 women; low-certainty evidence), but the evidence is uncertain. The evidence is very uncertain about the effect of lateral postures on severe perineal tears (RR 0.66, 95% CI 0.17 to 2.48; 3 trials, 609 women; very low-certainty evidence), postpartum haemorrhage (RR 0.90, 95% CI 0.48 to 1.70; 1 trial, 322 women; very low-certainty evidence), serious neonatal morbidity (RR 1.41, 95% CI 0.64 to 3.12; 3 trials, 752 babies; very low-certainty evidence), Apgar scores less than seven at five minutes (RR 0.25, 95% CI 0.03 to 2.24; 1 trial, 322 babies; very low-certainty evidence), admissions to neonatal intensive care (RR 1.41, 95% CI 0.64 to 3.12; 2 trials, 542 babies; very low-certainty evidence) and neonatal death (stillbirth or death of liveborn) (1 trial, 210 women and their babies; no events).  For the lateral posture comparisons, no data were reported for epidural use, neonatal encephalopathy, need for respiratory support, and neonatal jaundice requiring phototherapy. We were not able to estimate the outcome death (stillbirth or death of liveborn infant) due to no events (1 trial, 210 participants).  AUTHORS' CONCLUSIONS: We found low- and very low-certainty evidence which indicated that the use of hands and knees posture or lateral postures in women in labour with a fetal malposition may have little or no effect on health outcomes of the mother or her infant. If a woman finds the use of hands and knees or lateral postures in labour comfortable there is no reason why they should not choose to use them. Further research is needed on the use of hands and knees and lateral postures for women with a malposition in labour. Trials should include further assessment of semi-prone postures, same-side-as-fetus lateral postures with or without hip hyperflexion, or both, and consider interventions of longer duration or that involve the early second stage of labour.

Manual rotation of occiput posterior or transverse positions: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The primary objective of this systematic review was to assess the association between spontaneous vaginal delivery and manual rotation during labor for occiput posterior or transverse positions. Our secondary objective was to assess maternal and neonatal outcomes.

DATA SOURCES

An electronic search of PubMed, EMBASE, ClinicalTrials.gov, and the Cochrane Register of Controlled Trials covered the period from January 2000 to September 2021, without language restrictions.

STUDY ELIGIBILITY CRITERIA

The eligibility criteria included all randomized trials with singleton pregnancies at ≥37 weeks of gestation comparing the manual rotation groups with the control groups. The primary outcome was the rate of spontaneous vaginal delivery. Additional secondary outcomes were rate of occiput posterior position at delivery, operative vaginal delivery, cesarean delivery, postpartum hemorrhage, obstetrical anal sphincter injury, prolonged second stage of labor, shoulder dystocia, neonatal acidosis, and phototherapy. Subgroup analyses were performed according to types of position (occiput posterior or occiput transverse), techniques used (whole-hand or digital rotation), and parity (nulliparous or parous).

METHODS

The quality of each study was evaluated with the revised Cochrane risk-of-bias tool for randomized trials, known as RoB 2. The meta-analysis used random-effects models depending on their heterogeneity, and risks ratios were calculated for dichotomous outcomes.

RESULTS

Here, 7 of 384 studies met the inclusion criteria and were selected. They included 1402 women: 704 in the manual rotation groups and 698 in the control groups. Manual rotation was associated with a higher rate of spontaneous vaginal delivery: 64.9% vs 59.5% (risk ratio, 1.09; 95% confidence interval, 1.03-1.16; P=.005; 95% prediction interval, 0.90-1.32). This association was no longer significant after stratification by parity or technique used. Manual rotation was associated with spontaneous vaginal delivery only for the occiput posterior position (risk ratio, 1.08; 95% confidence interval, 1.01-1.15). Furthermore, it was associated with a reduction in occiput posterior or transverse positions at delivery (risk ratio, 0.64; 95% confidence interval, 0.48-0.87) and episiotomies (risk ratio, 0.84; 95% confidence interval, 0.71-0.98). The groups did not differ significantly for cesarean deliveries, operative vaginal deliveries, or neonatal outcomes.

CONCLUSION

Manual rotation increased the rate of spontaneous vaginal delivery.