Outcome of breech delivery at term.

OBJECTIVE--To compare neonatal mortality and morbidity in term infants presenting by the breech and delivered vaginally or by caesarean section. DESIGN--Population based comparison of outcomes. Data derived from the St Mary''s maternity information system. SETTING--North West Thames Regional Health Authority, 1988-90. SUBJECTS--3447 singleton fetuses presenting by the breech at term. MAIN OUTCOME MEASURES--Intrapartum and neonatal mortality, low Apgar scores, intubation at birth, and admission to special care baby units. RESULTS--After the exclusion of babies with congenital anomalies the incidence of intrapartum and neonatal death associated with vaginal birth was 8/961 (0.83%) compared with 1/2486 (0.03%) in babies born by caesarean section (relative risk 20, 95% confidence interval 2.5 to 163). The numbers of low Apgar scores and neonatal intubation were doubled in babies born vaginally or by emergency caesarean section compared with those delivered by elective operation. CONCLUSIONS--The good neonatal outcome associated with elective caesarean delivery of the term breech fetus may influence the decision of women and their obstetricians about mode of delivery.     

Maternal and neonatal individual risks and benefits associated with caesarean delivery: multicentre prospective study

Objective To assess the risks and benefits associated with caesarean delivery compared with vaginal delivery.Design Prospective cohort study within the 2005 WHO global survey on maternal and perinatal health.Setting 410 health facilities in 24 areas in eight randomly selected Latin American countries; 123 were randomly selected and 120 participated and provided dataParticipants 106 546 deliveries reported during the three month study period, with data available for 97 095 (91% coverage).Main outcome measures Maternal, fetal, and neonatal morbidity and mortality associated with intrapartum or elective caesarean delivery, adjusted for clinical, demographic, pregnancy, and institutional characteristics.Results Women undergoing caesarean delivery had an increased risk of severe maternal morbidity compared with women undergoing vaginal delivery (odds ratio 2.0 (95% confidence interval 1.6 to 2.5) for intrapartum caesarean and 2.3 (1.7 to 3.1) for elective caesarean). The risk of antibiotic treatment after delivery for women having either type of caesarean was five times that of women having vaginal deliveries. With cephalic presentation, there was a trend towards a reduced odds ratio for fetal death with elective caesarean, after adjustment for possible confounding variables and gestational age (0.7, 0.4 to 1.0). With breech presentation, caesarean delivery had a large protective effect for fetal death. With cephalic presentation, however, independent of possible confounding variables and gestational age, intrapartum and elective caesarean increased the risk for a stay of seven or more days in neonatal intensive care (2.1 (1.8 to 2.6) and 1.9 (1.6 to 2.3), respectively) and the risk of neonatal mortality up to hospital discharge (1.7 (1.3 to 2.2) and 1.9 (1.5 to 2.6), respectively), which remained higher even after exclusion of all caesarean deliveries for fetal distress. Such increased risk was not seen for breech presentation. Lack of labour was a risk factor for a stay of seven or more days in neonatal intensive care and neonatal mortality up to hospital discharge for babies delivered by elective caesarean delivery, but rupturing of membranes may be protective.Conclusions Caesarean delivery independently reduces overall risk in breech presentations and risk of intrapartum fetal death in cephalic presentations but increases the risk of severe maternal and neonatal morbidity and mortality in cephalic presentations.     

Which deliveries require paediatricians in attendance?

The mode of delivery and one minute Apgar score were taken from the neonatal records of 2086 full term infants born at one obstetric unit over 12 months. There were 1554 spontaneous vaginal vertex deliveries, 26 vaginal breech deliveries, and 506 operative or instrumental deliveries. The obstetric records of the operative deliveries were reviewed to determine whether fetal distress had been an indication for intervention, and the obstetric records of the spontaneous vaginal vertex deliveries were also reviewed for fetal distress detected antenatally. When fetal distress was present antenatally in spontaneous vaginal vertex deliveries the frequency of a one minute Apgar score below 7 was 10.2%. In operative and instrumental deliveries where fetal distress was the indication for intervention the frequency of one a minute Apgar score below 7 was 15.6% after non-rotational forceps delivery, 13.9% after rotational forceps delivery, and 45.8% after caesarean section. In the absence of fetal distress the frequency of an Apgar score below 7 was 2.4% after spontaneous deliveries, 7.1% after non-rotational forceps delivery, 13.2% after caesarean section, and 18.4% after rotational forceps delivery. The presence of fetal distress considerably increased the frequency of an Apgar score below 7 in each category except rotational forceps deliveries. Paediatric services to an obstetric unit may be organised rationally in the light of local staffing conditions with the help of these findings.     

Changes of nitric oxide, carbon monoxide and oxidative stress in term infants at birth

The higher risk of respiratory problem in infants delivered by elective caesarean section in comparison with vaginally born infants may be favoured by lower level of nitric oxide (NO) and carbon monoxide (CO) and higher oxidative stress in infants born by caesarean section. We studied healthy term infants born by vaginal delivery or by elective caesarean section. Nitric oxide, CO, guanosine 3-5 cyclic monophosphate, total hydroperoxide and advanced oxidation protein products (AOPP) were measured at birth and 48-72 h of life. Nitric oxide, CO and cGMP were lower at birth and at 48-72 h of life in infants born by elective caesarean delivery. Total hydroperoxide and AOPP levels were similar in the two groups and increased from birth to 48-72 h of life. In conclusion, nitric oxide and CO concentrations were higher in term infants vaginally born than in infants born by elective caesarean section and decreased from birth to 48-72 h of life. The mode of delivery did not affect the oxidative stress which increases from birth to 48-72 h of life.     

Changes of nitric oxide,carbon monoxide and oxidative stress in term infants at birth

The higher risk of respiratory problem in infants delivered by elective caesarean section in comparison with vaginally born infants may be favoured by lower level of nitric oxide (NO) and carbon monoxide (CO) and higher oxidative stress in infants born by caesarean section. We studied healthy term infants born by vaginal delivery or by elective caesarean section. Nitric oxide, CO, guanosine 3–5 cyclic monophosphate, total hydroperoxide and advanced oxidation protein products (AOPP) were measured at birth and 48–72 h of life. Nitric oxide, CO and cGMP were lower at birth and at 48–72 h of life in infants born by elective caesarean delivery. Total hydroperoxide and AOPP levels were similar in the two groups and increased from birth to 48–72 h of life. In conclusion, nitric oxide and CO concentrations were higher in term infants vaginally born than in infants born by elective caesarean section and decreased from birth to 48–72 h of life. The mode of delivery did not affect the oxidative stress which increases from birth to 48–72 h of life.     

Impact of sex ratio on onset and management of labour.

In a study of 52,266 live singleton deliveries in a total population male babies were delivered at earlier gestations than female. This difference was not due to induction or elective caesarean section. Female babies were more likely to present and be delivered by the breech. When the presentation was cephalic, male babies were much more likely to be delivered by forceps or caesarean section and female babies to deliver spontaneously.     

Mode of delivery and survival in babies weighing less than 2000 g at birth.

A retrospective study of babies weighing less than 2000 g at birth admitted over a four-year period to Nottingham City Hospital Neonatal Unit showed a higher incidence of lower Apgar scores and the need for intubation in babies born by caesarean section and breech deliveries. Mortality in those delivered by the breech (35%) was statistically higher than those by caesarean section (10%) or vertex (14%). It is concluded that small babies born by breech delivery have a higher mortality than when delivered vaginally and should have the benefit of caesarean section.     

Should all twins be delivered by caesarean section? A preliminary report.

The aim was to analyse the neonatal mortality related to mode of delivery for twins using a population-based registry. In all, 18,125 twins delivered in Sweden between 1991 and 1997, after excluding those with unknown gestational duration, were used to analyse the differences between groups of twins. Results showed the OR for neonatal death, breech vaginal delivery versus caesarean section (all indications) was 1.47 (95% CI 0.99-2.17). The OR at vaginal delivery for neonatal death, twin I in breech versus cephalic presentation was 5.60 (2.62-11.94) and for twin II the corresponding figures were 1.85 (1.03-3.32). Analyses using population-based registries from other countries are needed to confirm or reject the present findings of an increased neonatal mortality for twins in breech presentation delivered vaginally.     

Neurological follow-up of 281 children born in breech presentation: a controlled study.

A study was conducted of all children delivered in breech presentation from 1969 to 1977 in the university''s department of obstetrics. One-fifth of the deliveries were by caesarean section. Perinatal mortality was high (13.2%) but was due almost exclusively to causes other than the birth itself. The 256 surviving children and their matched controls were neurologically examined at 18 months or at ages varying between 3 and 10 years. The attrition rate was 5.7%, but in most cases data on development were available. Significant differences between the study and control groups existed for only minor neurological dysfunctions. It is concluded that the main danger of breech presentation is in the associated complications of pregnancy and that there is no reason to advocate a higher frequency of abdominal delivery than the 20% found in this study.     

Role of pelvimetry in active management of labour.

All cases referred for pelvimetry in 1970-1 and all breech presentations referred for pelvimetry in 1972-4 were reviewed. Indications for pelvimetry fell into four main categories: high head in the antenatal clinic (47-8%); high head in labour (13-9%); breech presentation (20-9%); and previous caesarean section (14-8%). In the first two categories pelvimetry rarely if ever influenced management, and it should not be performed routinely. In breech presentation and cases of caesarean section pelvimetry seemed to be of value, but in the latter group it should be performed puerperally to avoid the known radiation hazard to the fetus. A fairly close correlation between obstetric conjugate and pelvic capacity was shown, which suggested that a 3400-g baby might pass through a pelvis of obstetric conjugate of 10 cm as a cephalic trial of labour, but would need an obstetric conjugate of 11-7 cm for safe vaginal breech delivery.     

Twin entanglement revisited.

A fear of interlocking twins is one factor that has led to a high Cesarean section (C/S) rate in breech (A)/vertex (B) (Br(a)/Vtx(b)) twins. We sought to estimate the frequency of occurrence of twin entanglement, and of interlocking Br(a)/Vtx(b) twins in vaginal deliveries. 541 twins and 48,195 deliveries were retrospectively studied for the period 1987-1995. The incidence of Br(a)/Vtx(b) deliveries was noted, and the number of deliveries marked by interlocking and collision of fetuses. The mode of delivery, reason for C/S, and sources of perinatal mortality were noted. Only 43 deliveries were Br(a)/Vtx(b) (7.9% of all twins) and of these only 14 (32.6%) were delivered vaginally. One case of interlocking (2.3% of all Br(a)/Vtx(b) pairs) and five cases of collision of twins (ie competition for entry into the pelvic inlet with obstruction) were noted. All cases mentioned were delivered by C/S. No perinatal mortality resulted from these cases. In recent years the trend has been for greater use of C/S and ultrasound in managing twin deliveries. In this study 67.4% of Br(a)/Vtx(b) twins were delivered by C/S. Although there are fewer vaginal deliveries of these twins and the rate for interlocking (2.3%; 95% CI: 0.06-12.3%) for the whole group has remained about the same, we found the rate in those twins allowed vaginal delivery was 6.7% (95% CI: 0.2-31.9%). The presentation at greatest risk for entanglement was found to be Br(a)/Vtx(b).     

Uterine Rupture by Intended Mode of Delivery in the UK: A National Case-Control Study

Background

Recent reports of the risk of morbidity due to uterine rupture are thought to have contributed in some countries to a decrease in the number of women attempting a vaginal birth after caesarean section. The aims of this study were to estimate the incidence of true uterine rupture in the UK and to investigate and quantify the associated risk factors and outcomes, on the basis of intended mode of delivery.

Methods and Findings

A UK national case-control study was undertaken between April 2009 and April 2010. The participants comprised 159 women with uterine rupture and 448 control women with a previous caesarean delivery. The estimated incidence of uterine rupture was 0.2 per 1,000 maternities overall; 2.1 and 0.3 per 1,000 maternities in women with a previous caesarean delivery planning vaginal or elective caesarean delivery, respectively. Amongst women with a previous caesarean delivery, odds of rupture were also increased in women who had ≥ two previous caesarean deliveries (adjusted odds ratio [aOR] 3.02, 95% CI 1.16–7.85) and <12 months since their last caesarean delivery (aOR 3.12, 95% CI 1.62–6.02). A higher risk of rupture with labour induction and oxytocin use was apparent (aOR 3.92, 95% CI 1.00–15.33). Two women with uterine rupture died (case fatality 1.3%, 95% CI 0.2–4.5%). There were 18 perinatal deaths associated with uterine rupture among 145 infants (perinatal mortality 124 per 1,000 total births, 95% CI 75–189).

Conclusions

Although uterine rupture is associated with significant mortality and morbidity, even amongst women with a previous caesarean section planning a vaginal delivery, it is a rare occurrence. For women with a previous caesarean section, risk of uterine rupture increases with number of previous caesarean deliveries, a short interval since the last caesarean section, and labour induction and/or augmentation. These factors should be considered when counselling and managing the labour of women with a previous caesarean section. Please see later in the article for the Editors'' Summary     

Spontaneous preterm labour and delivery at under 34 weeks' gestation.

The management and outcome of 242 infants delivered between 26 and 34 weeks'' gestation in an obstetrical and neonatal regional referral centre as a result of spontaneous preterm labour were recorded prospectively. Results of the survey show that the decision to intervene and delay delivery will depend on the availability of neonatal intensive care facilities. Infants likely to require intensive neonatal care should be transferred in utero to a centre with these facilities. The use of steroids reduces the mortality of preterm infants. The maximum effect occurs between 30 and 32 weeks'' gestation, and there is no benefit after 34 weeks. If the weight is over 1500 g the mode of delivery of the preterm infant presenting by the breech does not influence outcome; if under 1500 g a caesarean section improves survival over those infants born by vaginal breech delivery.     

Differing Prevalence and Diversity of Bacterial Species in Fetal Membranes from Very Preterm and Term Labor

Background

Intrauterine infection may play a role in preterm delivery due to spontaneous preterm labor (PTL) and preterm prolonged rupture of membranes (PPROM). Because bacteria previously associated with preterm delivery are often difficult to culture, a molecular biology approach was used to identify bacterial DNA in placenta and fetal membranes.

Methodology/Principal findings

We used broad-range 16S rDNA PCR and species-specific, real-time assays to amplify bacterial DNA from fetal membranes and placenta. 74 women were recruited to the following groups: PPROM <32 weeks (n = 26; 11 caesarean); PTL with intact membranes <32 weeks (n = 19; all vaginal birth); indicated preterm delivery <32 weeks (n = 8; all caesarean); term (n = 21; 11 caesarean). 50% (5/10) of term vaginal deliveries were positive for bacterial DNA. However, little spread was observed through tissues and species diversity was restricted. Minimal bacteria were detected in term elective section or indicated preterm deliveries. Bacterial prevalence was significantly increased in samples from PTL with intact membranes [89% (17/19) versus 50% (5/10) in term vaginal delivery p = 0.03] and PPROM (CS) [55% (6/11) versus 0% (0/11) in term elective CS, p = 0.01]. In addition, bacterial spread and diversity was greater in the preterm groups with 68% (13/19) PTL group having 3 or more positive samples and over 60% (12/19) showing two or more bacterial species (versus 20% (2/10) in term vaginal deliveries). Blood monocytes from women with PTL with intact membranes and PPROM who were 16S bacterial positive showed greater level of immune paresis (p = 0.03). A positive PCR result was associated with histological chorioamnionitis in preterm deliveries.

Conclusion/Significance

Bacteria are found in both preterm and term fetal membranes. A greater spread and diversity of bacterial species were found in tissues of women who had very preterm births. It is unclear to what extent the greater bacterial prevalence observed in all vaginal delivery groups reflects bacterial contamination or colonization of membranes during labor. Bacteria positive preterm tissues are associated with histological chorioamnionitis and a pronounced maternal immune paresis.     

Late results of cesarean and vaginal delivery in cases of breech presentation.

This study compared the subsequent development of children in breech presentation according to the method of their delivery - vaginal or cesarean section. No differences were found between children born vaginally and those born by cesarean section after some labour, except for a larger variability in the outcomes of the latter group. Only 4% of the deliveries were by cesarean section without labour, and when analysed separately the data for this group frequently showed the poorest outcome. Reasons for the observations are suggested, and proposed further research is outlined.     

Birth order,gestational age,and risk of delivery related perinatal death in twins: retrospective cohort study

ObjectiveTo determine whether twins born second are at increased risk of perinatal death because of complications during labour and delivery.DesignRetrospective cohort study.SettingScotland, 1992 and 1997.ParticipantsAll twin births at or after 24 weeks'' gestation, excluding twin pairs in which either twin died before labour or delivery or died during or after labour and delivery because of congenital abnormality, non-immune hydrops, or twin to twin transfusion syndrome.ResultsOverall, delivery related perinatal deaths were recorded for 23 first twins only and 23 second twins only of 1438 twin pairs born before 36 weeks (preterm) by means other than planned caesarean section (P>0.99). No deaths of first twins and nine deaths of second twins (P=0.004) were recorded among the 2436 twin pairs born at or after 36 weeks (term). Discordance between first and second twins differed significantly in preterm and term births (P=0.007). Seven of nine deaths of second twins at term were due to anoxia during the birth (2.9 (95% confidence interval 1.2 to 5.9) per 1000); five of these deaths were associated with mechanical problems with the second delivery following vaginal delivery of the first twin. No deaths were recorded among 454 second twins delivered at term by planned caesarean section.ConclusionsSecond twins born at term are at higher risk than first twins of death due to complications of delivery. Previous studies may not have shown an increased risk because of inadequate categorisation of deaths, lack of statistical power, inappropriate analyses, and pooling of data about preterm births and term births.

What is already known on this topic

It is difficult to assess the wellbeing of second twins during labourDeliveries of second twins are at increased risk of mechanical problems, such as cord prolapse and malpresentation, after vaginal delivery of first twinsIncreased risks of perinatal death in second twins have not been shown, but the methods of these studies were flawed

What this study adds

Second twins delivered at term are at increased risk of delivery related perinatal deathsIntrapartum anoxia caused 75% of these deaths in second twins, and most of these resulted from mechanical problems after vaginal delivery of first twinsPlanned caesarean section of twins at term may prevent perinatal deaths     

External cephalic version of the term breech baboon (Papio sp.) fetus

BACKGROUND: Breech presentation in baboons may be associated with head entrapment and stillbirth during vaginal delivery. For this reason, pregnant dams at our institution typically undergo cesarean delivery for known breech presentation, leading to problems with maternal-infant bonding and increased nursery utilization. METHODS: This paper describes a simple, non-invasive technique called external cephalic version (ECV) that effectively converts the baboon breech fetus into a cephalic presentation. RESULTS: ECV was successful in each of seven attempted cases, with the consistent development of contractions and vaginal bleeding leading to the delivery of a healthy liveborn infant within 72 hours. CONCLUSIONS: ECV may offer a safe and effective alternative to cesarean section for delivery of the breech baboon fetus.     

不同分娩方式对晚期早产儿肠道菌群的影响

目的 探讨不同分娩方式对晚期早产儿肠道菌群定植的影响。方法 以胎龄(周)为34~(0/7)～36~(6/7)的15例晚期早产儿为研究对象,根据分娩方式分为自然分娩组(n=8)和剖宫产组(n=7)。收集早产儿出生后3 d、7 d、14 d的粪便标本,应用高通量测序技术对细菌16S rRNA可变区中的V4区进行测序,分析肠道菌群多样性及组成结构。结果 (1)自然分娩组晚期早产儿粪便标本菌群多样性指数逐渐上升,剖宫产组的多样性指数较平稳,两组相比差异无统计学意义;(2)45份粪便标本中共检测出10个菌门,均以变形菌门、厚壁菌门、放线菌门和拟杆菌门为优势菌门,两组晚期早产儿生后变形菌门、拟杆菌门所占比例逐渐降低,厚壁菌门、放线菌门呈增多趋势。两组相比,剖宫产组7 d、14 d时拟杆菌门的相对丰度显著低于自然分娩组(Z=-2.896,P=0.004;Z=-2.120,P=0.040),变形菌门相对丰度仅在7 d时显著高于自然分娩组(Z=-2.190,P=0.030);(3)两组研究对象中,除自然分娩组14 d时以双歧杆菌属为优势菌属外,余下均以肠杆菌属为优势菌属。相比于自然分娩组,在7 d时剖宫产组拟杆菌属所占比例显著降低(Z=-2.806,P=0.005),肠杆菌属所占比例显著升高(Z=-2.199,P=0.030)。结论 剖宫产能显著影响婴儿早期肠道菌群的定植,降低肠道中早期拟杆菌的水平。     

Delivery after caesarean section: review of 2176 consecutive cases.

A total of 2176 consecutive patients who had had one previous caesarean section were studied retrospectively. A repeat elective caesarean section was performed in 395 (18.2%). Labour started spontaneously in 1363 patients, 301 of whom were given oxytocin to accelerate inert labour, and was induced by amniotomy and infusion of oxytocin in 418 women; 1618 of these 1781 patients (90.8%) delivered vaginally. Patients who had had a previous vaginal delivery were more likely to deliver vaginally again. Those women in whom the initial caesarean section had been performed during labour before the cervix was 4 cm dilated were less likely to deliver vaginally than those who had progressed further in labour or those who had had an elective caesarean section. Similarly, those who received oxytocin to stimulate inert labour were more likely to require a repeat caesarean section than those who did not. The uterine scar ruptured in only eight (0.45%) of the 1781 patients allowed into labour. The risk of rupture of the scar was not increased by the use of oxytocin alone either to induce or to accelerate labour. The combination of oxytocin to accelerate labour and epidural analgesia to provide pain relief, however, was associated with an increased incidence of scar rupture. Labour may be safely allowed in women who have had a previous caesarean section, most of whom will deliver vaginally. Induction of labour does not increase the risk of either a repeat caesarean section or rupture of a uterine scar.     

Maternal and paternal contribution to intergenerational recurrence of breech delivery: population based cohort study

Objective To investigate intergenerational recurrence of breech delivery, with a hypothesis that both women and men delivered in breech presentation contribute to increased risk of breech delivery in their offspring.Design Population based cohort study for two generations.Setting Data from the medical birth registry of Norway, based on all births in Norway 1967-2004 (2.2 million births).Participants Generational data were provided through linkage by national identification numbers, forming 451 393 mother-offspring units and 295 253 father-offspring units. We included units where both parents and offspring were singletons and offspring were first born, forming 232 704 mother-offspring units and 154 851 father-offspring units for our analyses.Main outcome measure Breech delivery in the second generation.Results Men and women who themselves were delivered in breech presentation had more than twice the risk of breech delivery in their own first pregnancies compared with men and women who had been cephalic presentations (odds ratios 2.2, 95% confidence interval 1.8 to 2.7, and 2.2, 1.9 to 2.5, for men and women, respectively). The strongest risks of recurrence were found for vaginally delivered offspring and were equally strong for men and women. Increased risk of recurrence of breech delivery in offspring was present only for parents delivered at term.Conclusion Intergenerational recurrence risk of breech delivery in offspring was equally high when transmitted through fathers and mothers. It seems reasonable to attribute the observed pattern of familial predisposition to term breech delivery to genetic inheritance, predominantly through the fetus.