Fetal Malpresentation and Malposition

Face presentation at term: incidence, risk factors and influence on maternal and neonatal outcomes

OBJECTIVES

The incidence, diagnosis, management and outcome of face presentation at term were analysed.

METHODS

A retrospective, gestational age-matched case-control study including 27 singletons with face presentation at term was conducted between April 2006 and February 2021. For each case, four women who had the same gestational age and delivered in the same month with vertex position and singletons were selected as the controls (control group, n = 108). Conditional logistic regression was used to assess the risk factors of face presentation. The maternal and neonatal outcomes of the face presentation group were followed up.

RESULTS

The incidence of face presentation at term was 0.14‰. After conditional logistic regression, the two factors associated with face presentation were high parity (adjusted odds ratio [aOR] 2.76, 95% CI 1.19-6.39)] and amniotic fluid index > 18 cm (aOR 2.60, 95% CI 1.08-6.27). Among the 27 cases, the diagnosis was made before the onset of labor, during the latent phase of labor, during the active phase of labor, and during the cesarean section in 3.7% (1/27), 40.7% (11/27), 11.1% (3/27) and 44.4% (12/27) of cases, respectively. In one case of cervical dilation with a diameter of 5 cm, we innovatively used a vaginal speculum for rapid diagnosis of face presentation. The rate of cesarean section and postpartum haemorrhage ≥ 500 ml in the face presentation group was higher than that of the control group (88.9% vs. 13.9%, P < 0.001, and 14.8% vs. 2.8%, P = 0.024), but the Apgar scores were similar in both sets of newborns. Among the 27 cases of face presentation, there were three cases of adverse maternal and neonatal outcomes, including one case of neonatal right brachial plexus injury and two cases of severe laceration of the lower segment of the uterus with postpartum haemorrhage ≥ 1000 ml.

CONCLUSIONS

Face presentation was rare. Early diagnosis is difficult, and thus easily neglected. High parity and amniotic fluid index > 18 cm are risk factors for face presentation. An early diagnosis and proper management of face presentation could lead to good maternal and neonatal outcomes.

The influence of birthweight on mortality and severe neonatal morbidity in late preterm and term infants: an Australian cohort study

Background

The aim of this study was to detail incidence rates and relative risks for severe adverse perinatal outcomes by birthweight centile categories in a large Australian cohort of late preterm and term infants.

Methods

This was a retrospective cohort study of singleton infants (≥34+0 weeks gestation) between 2000 and 2018 in Queensland, Australia. Study outcomes were perinatal mortality, severe neurological morbidity, and other severe morbidity. Categorical outcomes were compared using Chi-squared tests. Continuous outcomes were compared using t-tests. Multinomial logistic regression investigated the effect of birthweight centile on study outcomes.

Findings

The final cohort comprised 991,042 infants. Perinatal mortality occurred in 1944 infants (0.19%). The incidence and risk of perinatal mortality increased as birthweight decreased, peaking for infants <1st centile (perinatal mortality rate 13.2/1000 births, adjusted Relative Risk Ratio (aRRR) of 12.96 (95% CI 10.14, 16.57) for stillbirth and aRRR 7.55 (95% CI 3.78, 15.08) for neonatal death). Severe neurological morbidity occurred in 7311 infants (0.74%), with the highest rate (19.6/1000 live births) in <1st centile cohort. There were 75,243 cases of severe morbidity (7.59% livebirths), with the peak incidence occurring in the <1st centile category (12.3% livebirths). The majority of adverse outcomes occurred in infants with birthweights between 10 and 90th centile. Almost 2 in 3 stillbirths, and approximately 3 in 4 cases of neonatal death, severe neurological morbidity or other severe morbidity occurred within this birthweight range.

Interpretation

Although the incidence and risk of perinatal mortality, severe neurological morbidity and severe morbidity increased at the extremes of birthweight centiles, the majority of these outcomes occurred in infants that were apparently "appropriately grown" (i.e., birthweight 10th-90th centile).

Funding

National Health and Medical Research Council, Mater Foundation, Royal Australian College of Obstetricians and Gynaecologists Women's Health Foundation - Norman Beischer Clinical Research Scholarship, Cerebral Palsy Alliance, University of Queensland Research Scholarship.

The Pathophysiology of Labor Dystocia: Theme with Variations

Abnormally prolonged labor, or labor dystocia, is a common complication of parturition. It is the indication for about half of unplanned cesarean deliveries in low-risk nulliparous women. Reducing the rate of unplanned cesarean birth in the USA has been a public health priority over the last two decades with limited success. Labor dystocia is a complex disorder due to multiple causes with a common clinical outcome of slow cervical dilation and fetal descent. A better understanding of the pathophysiologic mechanisms of labor dystocia could lead to new clinical opportunities to increase the rate of normal vaginal delivery, reduce cesarean birth rates, and improve maternal and neonatal health. We conducted a literature review of the causes and pathophysiologic mechanisms of labor dystocia. We summarize known mechanisms supported by clinical and experimental data and newer hypotheses with less supporting evidence. We review recent data on uterine preparation for labor, uterine contractility, cervical preparation for labor, maternal obesity, cephalopelvic disproportion, fetal malposition, intrauterine infection, and maternal stress. We also describe current clinical approaches to preventing and managing labor dystocia. The variation in pathophysiologic causes of labor dystocia probably limits the utility of current general treatment options. However, treatments targeting specific underlying etiologies could be more effective. We found that the pathophysiologic basis of labor dystocia is under-researched, offering wide opportunities for translational investigation of individualized labor management, particularly regarding uterine metabolism and fetal position. More precise diagnostic tools and individualized therapies for labor dystocia might lead to better outcomes. We conclude that additional knowledge of parturition physiology coupled with rigorous clinical evaluation of novel biologically directed treatments could improve obstetric quality of care.

Emergency Delivery

Despite the majority of US births occurring in hospitals and under the direct care of obstetricians, there is a subset of patients who will deliver imminently in the emergency department (ED). ED physicians must be skillfully trained to manage both uncomplicated and complicated delivery scenarios. An ED delivery may require resuscitation of both mother and infant, so supplies should be readily available and all necessary consultants and support staff should be involved to ensure the best outcome. Most births are uncomplicated and require no significant additional interventions but ED staff must be prepared for these more complicated scenarios.

What to do when it is breech? A state-of-the-art review on management of breech presentation

Any non-cephalic presentation in a fetus is regarded as malpresentation. The most common malpresentation, breech, contributes to 3%-5% of term pregnancies and is a leading indication for cesarean delivery. Identification of risk factors and a proper physical examination are beneficial; however, ultrasound is the gold standard for the diagnosis of malpresentations. External cephalic version (ECV) refers to a procedure aimed to convert a non-cephalic presenting fetus to cephalic presentation. This procedure is performed manually through the mother’s abdomen by a trained health care provider, to reduce the likelihood of a cesarean section. Studies have reported a version success rate of above 50% by ECV. The main objective of this review is to present a broad perspective on fetal malpresentation, ECV, and delivery of a breech fetus. The focus is to elaborate all clinical scenarios of breech and to provide an evidence-based clinical approach for them. After discussing breech prevalence, risk factors, diagnosis, and management, an updated review of ECV is presented. Moreover, ECV indications/contraindications, alternatives, clinical techniques on how to perform ECV and breech vaginal delivery, and obstetrical considerations for the delivery of malpresentations are thoroughly discussed.

The impact of intrapartum and immediate post-partum complications and newborn care practices on breastfeeding initiation in Ethiopia: A prospective cohort study

This study aimed to investigate the impact of intrapartum and post-partum complications and newborn care practices on early initiation of breastfeeding (EIBF). Data for the study came from a prospective cohort study in Ethiopia that recruited and followed pregnant and post-partum women from 2019 to 2021. Resident enumerators conducted interviews at enrolment in 2019 and follow-ups at 6 weeks, 6 months and 1 year post-partum. The present analysis is based on data from the baseline survey and 6 weeks follow-up. Multivariable logistic regression was used to estimate the effects of newborn care practices and intrapartum and post- partum complications on EIBF (the proportion of newborns who initiated breastfeeding within the first hour of birth). Overall, 2660 mother-infant pairs were included in this analysis. After adjustment, EIBF was less likely among women who experienced intrapartum haemorrhage (adjusted odds ratio [AOR]: 0.76, 95% confidence interval [CI]: 0.59-0.97), malpresentation (AOR: 0.46, 95% CI: 0.30-0.72) and convulsions (AOR: 0.48, 95% CI: 0.34-0.66) during childbirth. Mother-newborn skin-to-skin contact increased the likelihood of EIBF (AOR: 1.47, 95% CI: 1.11-1.94). Women who experienced post-partum haemorrhage (AOR: 0.63, 95% CI: 0.47-0.84), retained placenta for more than 30 min (AOR: 0.36, 95% CI: 0.24-0.52) and convulsions after delivery (AOR: 0.57, 95% CI: 0.41-0.79) were less likely to initiate breastfeeding early. Also, women who had a caesarean birth (AOR: 0.28, 95% CI: 0.18-0.41), delivered outside of a healthcare facility (AOR: 0.70, 95% CI: 0.50-0.99) or had twin birth (AOR: 0.43, 95% CI: 0.22-0.85) were less likely to initiate breastfeeding early. Skin-to-skin contact should be encouraged whenever possible, and women with obstetric complications should be encouraged and supported to initiate breastfeeding early.

A biomechanical study of the birth position: a natural struggle between mother and fetus

Birth trauma affects millions of women and infants worldwide. Levator ani muscle avulsions can be responsible for long-term morbidity, associated with 13-36% of women who deliver vaginally. Pelvic floor injuries are enhanced by fetal malposition, namely persistent occipito-posterior (OP) position, estimated to affect 1.8-12.9% of pregnancies. Neonates delivered in persistent OP position are associated with an increased risk for adverse outcomes. The main goal of this work was to evaluate the impact of distinct fetal positions on both mother and fetus. Therefore, a finite element model of the fetal head and maternal structures was used to perform childbirth simulations with the fetus in the occipito-anterior (OA) and OP position of the vertex presentation, considering a flexible-sacrum maternal position. Results demonstrated that the pelvic floor muscles' stretch was similar in both cases. The maximum principal stresses were higher for the OP position, and the coccyx rotation reached maximums of 2.17[Formula: see text] and 0.98[Formula: see text] for the OP and OA positions, respectively. Concerning the fetal head, results showed noteworthy differences in the variation of diameters between the two positions. The molding index is higher for the OA position, with a maximum of 1.87. The main conclusions indicate that an OP position can be more harmful to the pelvic floor and pelvic bones from a biomechanical point of view. On the other side, an OP position can be favorable to the fetus since fewer deformations were verified. This study demonstrates the importance of biomechanical analyses to further understand the mechanics of labor.

Fetal head malposition and epidural analgesia in labor: a case-control study

BACKGROUND

The fetal head malposition in labor leads to prolonged labor, cesarean delivery and increased perinatal morbidity. Epidural analgesia has been associated with fetal head malposition, but it remains unknown if this relation is causal.

OBJECTIVE

To compare the incidence of fetal malposition during labor and maternal/fetal outcomes, between women who received epidural analgesia with those who did not use the analgesic method.

STUDY DESIGN

Case control study including 500 women with a single fetus in vertex position who gave birth at term at the Policlinic Hospital of Modena between May 2019 and July 2019. Two-hundred and fifty women belonged to the epidural analgesia (EA) group and 250 to the control group.

RESULTS

The rate of posterior occiput positions occurred 4 times more frequently in the EA group than in the control group (8.8% vs 2.2%, p = .004). Cesarean sections were significantly higher in the EA group (11.6% vs 1.6%, p < .0000) as well as the need for augmentation with oxytocin (20% vs 8%, p = .0001) compared to the control group, in which spontaneous delivery prevailed instead. Women with epidural had labors that lasted on average 7.0 h against the 3.30 h of controls (p < .0000). The length of 2nd stage of labor was 55 vs 30 min (p = .009), respectively. No differences in blood loss and Apgar score between groups. Early breastfeeding was significantly higher among controls (82% vs 92.8%, p = .0004).

CONCLUSIONS

Women receiving epidural analgesia in labor have higher rate of fetal malposition, prolonged labors, and more cesarean sections than controls. However, further studies are required to confirm a causal association between EA and fetal head malposition.

The association between longer durations of the latent phase of labor and subsequent perinatal processes and outcomes among midwifery patients

BACKGROUND/OBJECTIVE

To evaluate the association between the duration of the latent phase of labor and subsequent processes and outcomes.

METHODS

Secondary analysis of prospectively collected data among 1,189 women with low-risk pregnancies and spontaneous labor.

RESULTS

Longer latent phase duration was associated with labor dystocia (eg, nulliparous ≥ mean [compared with < mean] aOR 3.95 [2.70-5.79]; multiparous ≥ mean [compared with < mean] aOR 5.45 [3.43-8.65]), interventions to ameliorate dystocia, and epidurals to cope or rest (eg, oxytocin augmentation: nulliparous > 80th% [compared with < 80th%] aOR 6.39 [4.04-10.12]; multiparous ≥ 80th% [compared with < 80th%] aOR 6.35 [3.79-10.64]). Longer latent phase duration was also associated with longer active phase and second stage. There were no associations between latent phase duration and risk for cesarean delivery or postpartum hemorrhage in a practice setting with relatively low rates of primary cesarean. Newborns born to multiparous women with latent phase of labor durations at and beyond the 80th% were more frequently admitted to the NICU (≥80th% [compared with < 80th%] aOR 2.7 [1.22-5.84]); however, two-thirds of these NICU admissions were likely for observation only.

CONCLUSIONS

Longer duration of the spontaneous latent phase of labor among women with low-risk pregnancies may signal longer total labor processes, leading to an increase in diagnosis of dystocia, interventions to manage dystocia, and epidural use. Apart from multiparous neonatal NICU admission, no other maternal or child morbidity outcomes were elevated with longer duration of the latent phase of labor.

Kielland's rotational forceps delivery: A comparison of maternal and neonatal outcomes with rotational ventouse or second stage caesarean section deliveries

OBJECTIVES

The objective of our study was to derive accurate estimates of risks of maternal and neonatal complications associated with Kielland's rotational forceps delivery (KRFD) compared to rotational ventouse delivery (RVD) or 2nd stage caesarean section (CS).

METHODS

This was a retrospective cohort study undertaken at a large tertiary maternity and neonatal unit in the United Kingdom between January 2010 and June 2018. Pregnancies with fetal demise, major fetal defects, those lost to follow-up, those delivering by elective or emergency CS in the first stage of labour and non-rotational instrumental deliveries were excluded. The study population included singleton pregnancies delivering by Kielland's forceps, rotational ventouse, 2nd stage CS or spontaneous unassisted cephalic vaginal delivery; the latter forming the control group. The maternal outcomes examined included post-partum haemorrhage (PPH) and obstetric anal sphincter injury (OASIS). The neonatal outcomes included admission to neonatal intensive care unit (NICU), 5-minute Apgar scores <7, hypoxic ischaemic encephalopathy (HIE), jaundice, shoulder dystocia and birth trauma. Absolute risks with 95 % confidence intervals (CI) were calculated in the study groups. Univariate and multivariate logistic regression analysis was carried out to estimate crude and adjusted odds ratio (OR) with 95 % CI.

RESULTS

The study population of 23,786 pregnancies included: 491 (2.1 %) requiring KRFD, 344 (1.4 %) requiring RVD, 840 (3.5 %) that had a 2nd stage CS and 22,111 (93.0 %) spontaneous cephalic vaginal deliveries. With regard to maternal adverse outcomes, in pregnancies that had a KRFD compared to RVD, there was no significant difference in the incidence of OASIS (p = 0.599) or PPH (p = 0.982). In contrast, the risk of PPH was significantly higher in those delivering by a 2nd stage CS compared to KRFD (27.5 % vs. 12.4 %; p < 0.0001). With regard to neonatal adverse outcomes, in those delivering by KRFD compared to RVD and 2nd stage CS, there was no significant difference in the incidence of admission to NICU (p = 0.912; p = 0.746, respectively), 5-minute Apgar score<7 (p = 0.335; p = 0.150, respectively), jaundice (p = 0.810; p = 0.332, respectively), mild shoulder dystocia (p = 0.077), severe shoulder dystocia (p = 0.603) or birth trauma (p = 0.265; p = 0.323, respectively). The risk of maternal composite adverse outcome was highest after 2nd stage CS (OR 7.68; 95 %CI: 6.52-9.04) and lowest after KRFD (OR 3.82; 95 %CI: 2.98-4.91). The risk of composite neonatal adverse outcome was higher in those delivering by RVD (OR 2.87; 95 %CI: 2.10-3.91), compared to KRFD (OR 2.23; 95 %CI: 1.67-2.97) or 2nd stage CS (OR 2.02; 95 %CI: 1.60-2.54).

CONCLUSION

Our study demonstrates that KRFD is a safer management option when compared to RVD or 2nd stage CS for the management of persistent fetal malposition in labour.

Sonographic diagnosis of fetal head deflexion and the risk of cesarean delivery

BACKGROUND

Malpositions and deflexed cephalic malpresentations are well recognized causes of dysfunctional labor, may result in fetal and maternal complications, and are diagnosed more precisely with an ultrasound examination than with a digital examination.

OBJECTIVE

This study aimed to assess the incidence of malpositions and deflexed cephalic malpresentations at the beginning of the second stage of labor and to evaluate the role of the sonographic diagnosis of deflexion in the prediction of the mode of delivery.

STUDY DESIGN

Women in labor with a singleton pregnancy at term with fetuses in a cephalic presentation at 10 cm of cervical dilatation were prospectively examined. A transabdominal ultrasound was performed to assess the fetal head position by demonstrating the fetal occiput or the eyes. Deflexion was assessed by the measurement of the occiput-spine angle when the occiput was anterior or transverse and by qualitative assessment of the relationship between chin and thorax when the occiput was posterior. Transperineal ultrasound was performed in occiput posterior fetuses to discriminate between sinciput, brow, and face presentation. Maternal, labor, and neonatal parameters including maternal age, induction of labor, use of epidural, birthweight, arterial pH, and neonatal intensive care unit admission were recorded. Patients were divided into 2 groups according to the sonographic diagnosis of head deflexion. Adjusted odds ratios were calculated using multivariate logistic regression to determine the association between cesarean delivery and the 2 groups. In addition, labor and neonatal characteristics were compared between occiput anterior and occiput posterior-occiput transverse fetuses.

RESULTS

Of the 200 women at the beginning of the second stage, the fetus was in occiput anterior position in 156 (78%), transverse in 11 (5.5%), and posterior in 33 (16.5%) cases. Deflexion was diagnosed in 33 of 156 (21.2%) occiput anterior fetuses and 19 of 44 (43.2%) occiput posterior and occiput transverse fetuses. Cesarean deliveries were significantly associated with fetal head deflexion both in occiput anterior (P=.001) and occiput posterior (P<.001) fetuses. Sonographic diagnosis of fetal head deflexion was an independent risk factor for cesarean delivery both in occiput anterior (adjusted odds ratio, 5.37; 95% confidence interval, 1.819-15.869) and occiput posterior (adjusted odds ratio, 13.9; 95% confidence interval, 1.958-98.671) cases, and it was an independent risk factor for cesarean delivery regardless of the occiput position (adjusted odds ratio, 5.83; 95% confidence interval, 2.47-13.73).

CONCLUSION

The sonographic diagnosis of fetal head deflexion at the beginning of the second stage increases the risk of cesarean delivery.

Difficult caesarean section: A literature review

BACKGROUND

Caesarean section (CS) is usually perceived as a simple and safe alternative to natural birth, but in some instances can be technically difficult with consequent health hazards for both the mother and the fetus. We have proposed an evidence-based literature review of the most common difficult CS scenarios, with the aim to provide useful information about their management, possible prevention and resolution of complications.

METHODS

We identified articles through a reserch in PubMed, Scopus, Web of Science and Ovid MEDLINE for studies published between 1979 and 2019. We included the best available evidence, such as RCTs, non-randomised controlled clinical trials, case-control studies, cohort studies, and case series. About sixty articles were included in this review, four hundred and thirty-six were excluded after reviewing the title or abstract or because they weren't in English.

FINDINGS

The possible causes of "difficult" caesarean sections were divided into four categories: difficult access to the lower uterine segment; complicated fetal extraction, laceration or organ damage and abnormal placentation.

CONCLUSIONS

Knowing in advance the potential technical difficulties and resulting risks allows the surgeon to plan appropriate strategies.

Describing latent phase duration and associated characteristics among 1281 low-risk women in spontaneous labor

BACKGROUND

Recent research suggests that latent phase of labor may terminate at 6 rather than 4 centimeters of cervical dilation. The objectives of this study were to: (a) characterize duration of the latent phase of labor among term, low-risk, United States women in spontaneous labor using the women's self-identified onset; and (b) quantify associations between demographic and maternal/newborn health characteristics and the duration of the latent phase.

METHODS

This prospective study (n = 1281) described the duration of the latent phase of labor in hours, stratified by parity at the mean, median, and 80th, 90th, and 95th percentiles. The duration of the latent phase was compared for each characteristic using t tests or Wilcoxon rank-sum tests and regression models that controlled for confounders.

RESULTS

In this sample of predominantly white, healthy women, duration of the latent phase of labor was longer than described in previous studies: The median duration was 9.0 hours and mean duration was 11.8 hours in nulliparous women. The median duration was 6.8 hours and mean duration was 9.3 hours in multiparous women. Among nulliparous women, longer duration was seen in women whose fetus was in a malposition. Among multiparous women, longer durations were noted in women with chorioamnionitis and those who gave birth between 41 and 41 + 6 weeks' gestation (vs between 40 and 40 + 6 weeks' gestation).

CONCLUSIONS

The latent phase of labor may be longer than previously estimated. Contemporary estimates of latent phase of labor duration will help women and providers accurately anticipate, prepare, and cope during spontaneous labor.