Delivery mode and intraventricular hemorrhage risk in very-low-birth-weight infants: Observational data of the German Neonatal Network

BACKGROUND

Very-low-birth-weight infants (VLBWI) are frequently delivered by cesarean section (CS). However, it is unclear at what gestational age the benefits of spontaneous delivery outweigh the perinatal risks, i.e. intraventricular hemorrhage (IVH) or death.

OBJECTIVES

To assess the short-term outcome of VLBWI on IVH according to mode of delivery in a population-based cohort of the German Neonatal Network (GNN).

STUDY DESIGN

A total cohort of 2203 singleton VLBWI with a birth weight <1500g and gestational age between 22 0/7 and 36 6/7 weeks born and discharged between 1st of January 2009 and 31st of December 2015 was available for analysis. VLBWI were stratified into three categories according to mode of delivery: (1) planned cesarean section (n=1381), (2) vaginal delivery (n=632) and (3) emergency cesarean section (n=190). Outcome was assessed in univariate and logistic regression analyses.

RESULTS

Prevalence of IVH was significantly higher in the vaginal delivery (VD) (26.6%) and emergency CS group (31.1%) as compared to planned CS (17.2%), respectively. In a logistic regression analysis including known risk factors for IVH, vaginal delivery (OR 1.725 [1.325-2.202], p≤0.001) and emergency cesarean section (OR 1.916 [1.338-2.746], p≤0.001) were independently associated with IVH risk. In the subgroup of infants >30 weeks of gestation prevalence for IVH was not significantly different in VD and planned CS (5.3% vs. 4.4%).

CONCLUSIONS

Our observational data demonstrate that elective cesarean section is associated with a reduced risk of IVH in preterm infants <30 weeks gestational age when presenting with preterm labor.

Uterine rupture risk after periviable cesarean delivery

OBJECTIVE

To investigate the risk of uterine rupture in women with prior periviable cesarean delivery and prior term cesarean delivery independent of initial incision type.

METHODS

We conducted a retrospective longitudinal cohort study using Washington state birth certificate data and hospital discharge records, identifying primary cesarean deliveries performed at 20-26 weeks and 37-41 weeks of gestation with subsequent delivery between 1989 and 2008. We compared subsequent uterine rupture risk in the two groups considering both primary incision type and subsequent labor induction and augmentation.

RESULTS

We identified 456 women with index periviable cesarean delivery and 10,505 women with index term cesarean delivery. Women with index periviable cesarean delivery were younger, more frequently of nonwhite race, more likely to smoke, and more likely to have hypertension. Women in the periviable group had more index classical incisions (42% compared with 1%, P<.001) and fewer subsequent inductions and augmentations (8% compared with 16%, P<.001). Uterine rupture in the subsequent pregnancy occurred more frequently among women in the index periviable group than those in the index term group (8/456 [1.8%] compared with 38/10,505 [0.4%], odds ratio [OR] 4.9, 95% confidence interval [CI] 2.3-10.6). This relationship persisted among women with a low transverse incision (4/228 [1.8%] compared with 36/9,558 [0.4%], OR 4.7, 95% CI 1.7-13.4).

CONCLUSION

Cesarean delivery at periviability compared with term is associated with an increased risk for uterine rupture in a subsequent pregnancy, even after low transverse incision. These data support judicious use of cesarean delivery at periviable gestational ages and inform subsequent counseling.

LEVEL OF EVIDENCE

II.

Comparison of fetal outcome in premature vaginal or cesarean breech delivery at 24-37 gestational weeks

PURPOSE

To compare the fetal outcome of preterm breech infants delivered vaginally (VD) or by cesarean section (CS).

METHODS

A monocentric, retrospective consecutive case series of preterm breech deliveries between 24-37 gestational weeks over 10 years from 1/2000 to 12/2009 was performed in a perinatal care center (Level 1) at the University Clinic of Salzburg, Austria. Data from hospital database were statistically analyzed and compared regarding birth weight, head circumference, parity, transfer rate to neonatal intensive care unit (NICU), arterial and venous cord blood pH and base excess (BE), arterial cord blood pH ≤ 7.10 and BE ≤ -11. Special focus was on fetal outcome of elective CS preterm breech deliveries with a non-urgent medical indication compared to VD.

RESULTS

Among 22.115 deliveries, there were 346 live-born preterm singletons and twins in breech presentation (1.56 %), born between 24 + 0 and 37 + 0 gestational weeks. 180 CS and 36 vaginally delivered preterm breech infants were statistically evaluated. On comparing CS vs. VD for premature breech singletons, arterial cord blood pH and BE were lower in the VD group. VD twins had a lower arterial cord blood pH than CS twins. All other parameters were comparable. In preterm breech singletons with non-urgent CS, a statistical analysis was not possible due to small numbers. The VD twin group revealed lower values in birth weight, head circumference, arterial cord blood pH and BE, but no significant difference in venous cord blood pH and BE and transfer rate to NICU.

CONCLUSIONS

Although general recommendations regarding a superior mode of delivery for improved fetal outcome of preterm breech infants cannot be given, these data do not support a policy of routine CS.

Mode of delivery at periviable gestational ages: impact on subsequent reproductive outcomes

AIM

The aim of this study was to assess the risk of subsequent delivery complications after extremely preterm deliveries by initial (index) pregnancy mode of delivery (MOD): cesarean (CD) versus vaginal (VD).

METHODS

This is a retrospective, longitudinal cohort study using Washington State birth certificate data and International Classification of Diseases, Ninth Revision codes, 1989-2008, identifying women with deliveries 20-26 weeks' gestation and linked subsequent deliveries. Index MOD was considered as a predictor of adverse subsequent maternal and neonatal outcomes, using t-test, χ(2)-test or Fisher's exact test, and regression analysis.

RESULTS

Of 2472 women with periviable delivery and subsequent birth, index CD (n=386) and index VD (n=2086) showed similar risks of composite morbidity (16.1% vs. 15.4%, P=0.76) and subsequent hemorrhage (9.6% vs. 11.1%, P=0.39). Women with index CD were more likely than index VD to experience uterine rupture (1.8% vs. 0.1%, P<0.001), to deliver earlier (35.9 vs. 36.9 weeks, P<0.001), and to have lower birth weight (2736 vs. 3014 g, P<0.001) subsequently. Neonatal hospital charges and lengths of stay were also higher after index CD.

CONCLUSIONS

MOD at extreme prematurity did not impact subsequent maternal hemorrhage or overall morbidity. However, CD was associated with substantial uterine rupture risk despite evidence of practice to avoid labor (lower birth weight and earlier delivery) in the subsequent pregnancy.

The Th1:th2 dichotomy of pregnancy and preterm labour

Pregnancy is a unique immunological state in which a balance of immune tolerance and suppression is needed to protect the fetus without compromising the mother. It has long been established that a bias from the T helper 1 cytokine profile towards the T helper 2 profile contributes towards successful pregnancy maintenance. The majority of publications that report on aberrant Th1:Th2 balance focus on early pregnancy loss and preeclampsia. Over the last few decades, there has been an increased awareness of the role of infection and inflammation in preterm labour, and the search for new biomarkers to predict preterm labour continues. In this paper, we explore the evidence for an aberrant Th1:Th2 profile associated with preterm labour. We also consider the potential for its use in screening women at high risk of preterm labour and for prophylactic therapeutic measures for the prevention of preterm labour and associated neonatal adverse outcomes.

Peroxisome proliferator-activated receptor gamma polymorphism and periodontitis in pregnant Japanese women

BACKGROUND

Recent studies suggest an association between maternal periodontitis and preterm birth, although the association remains controversial. It was suggested that mechanisms such as a genetic predisposition for a hyperinflammatory response cause periodontitis and preterm births. Peroxisome proliferator-activated receptor gamma (PPARgamma) is a nuclear hormone receptor and ligand-dependent transcription factor. PPARgamma inhibits the transcriptional activity of the genes that produce proinflammatory mediators and repress periodontitis. Recently, a common polymorphism, proline(PRO)-to-alanine(ALA) mutation at codon12 in exonB (Pro12Ala: rs 1801282) PPARgamma, was reported to reduce the ability to transactivate responsive promoters. In this study, we tested whether the PPARgammaPro12Ala polymorphism was associated with maternal periodontitis and/or preterm birth.

METHODS

Genomic DNA was isolated from the venous blood of pregnant Japanese women (term birth: n = 72; preterm birth: n = 58). The PPARgammaPro12Ala genotype was determined by polymerase chain reaction (PCR)-restriction fragment length polymorphism. Within 5 days after labor, clinical periodontal parameters were evaluated, and periodontopathic bacteria from the subgingival plaque were detected by species-specific PCR.

RESULTS

The mean clinical attachment level (P = 0.012), mean probing depth (P = 0.031), mean gingival index (P = 0.037), and percentages of sites with bleeding on probing (P = 0.041) in women with the PPARgammaPro12Ala genotype were significantly higher than in women with the PPARgammaPro12Pro genotype. However, there was no association between preterm birth and periodontitis.

CONCLUSION

We suggest that the PPARgammaPro12Ala polymorphism may represent a genetic susceptibility factor for the clinical measurements of periodontitis in a limited number of pregnant Japanese women, but it probably cannot influence the relationship between periodontitis and preterm birth.

Does cesarean section prevent mortality and cerebral ultrasound abnormalities in preterm newborns?

OBJECTIVE

Despite the increased use of the cesarean section (CS), the rates of cerebral palsy, a frequent consequence of brain damage, have remained stable over the last decades. Whether an actual decrease in cerebral palsy has been masked by increased survival of infants delivered by CS or not, remains undefined. To investigate the role of CS, we compared risks of mortality and brain damage, as defined by ultrasound (US) abnormalities, in preterm newborns by mode of delivery.

METHODS

Information on fetal, maternal, and neonatal risk factors was collected from the paired clinical records of preterm newborns and mothers. Crude and adjusted odds ratios (OR) of mortality and ultrasound abnormalities, according to mode of delivery (i.e., vaginal, elective CS, and emergency CS) were calculated. All the analyses were controlled for possible confounding by indication.

RESULTS

In newborns of gestational age <32 weeks, no effect of CS on cerebral US abnormalities was found (OR 0.71 and 0.73 for emergency CS and elective CS, respectively). None of the maternal and neonatal factors were associated with both cerebral US abnormalities and mode of delivery. Among newborns of gestational age >or=32 weeks, after controlling for known and potential confounders in a multivariate model, the adjusted ORs remained close to one for both elective CS and emergency CS.

CONCLUSIONS

CS does not reduce overall mortality in preterm newborns. No protective effect of CS on US abnormalities was found after stratifying by gestational age and controlling for possible confounding. These results do not encourage the widespread use of CS in preterm labor.

Impact of cesarean section on neonatal mortality rates among very preterm infants in the United States, 2000-2003

OBJECTIVE

The objective of this analysis was to compare the neonatal mortality rates for infants delivered through primary cesarean section versus vaginal delivery, taking into consideration a number of potentially risk-modifying conditions.

METHODS

US linked birth and infant death certificate files for 2000-2003 were used. Demographic, medical, and labor and delivery complications were abstracted from the files with infant information. The primary outcome examined was neonatal death (death at 0-27 days of age). Because of concern regarding misclassification of gestational age, a procedure was used to trim away births for which the birth weight for a specific gestational age was incongruous. Adjusted odds ratios were calculated for the risk of neonatal death relative to the mode of delivery (primary cesarean section versus vaginal delivery), using logistic regression analysis.

RESULTS

There were data for 13,733 neonatal deaths and 106,809 survivors available from the trimmed data set for analysis for the 4-year period. More than 80% of pregnancies with delivery between 22 and 31 weeks of gestation experienced >or=1 risk factor. Adjusted odds ratios demonstrated significantly reduced risk of neonatal death for infants delivered through cesarean section at 22 to 25 weeks of gestation (adjusted odds ratios of 0.58, 0.52, 0.72, and 0.81 for 22, 23, 24, and 25 weeks, respectively).

CONCLUSION

Cesarean section does seem to provide survival advantages for the most immature infants delivered at 22 to 25 weeks of gestation, independent of maternal risk factors for cesarean section.

Cesarean section and the outcome of very preterm and very low-birthweight infants

Births of extremely preterm infants, less than 26 weeks' gestation, by cesarean section have increased significantly in the United States over the past decade. The justification for this increase is not well supported in the literature. This review examines recent analyses that suggest there may be some survival advantage for infants less than 26 weeks delivered by cesarean section. The appropriateness of intervening with cesarean sections for these very immature infants, however, remains uncertain.

Incidence and correlates of cesarean section in a capital city of a middle-income country

OBJECTIVE

To determine the prevalence and correlates of cesarean deliveries (CS) in Beirut.

METHODS

A cross-sectional study conducted on 18,837 consecutive infants born at nine hospitals from the National Collaborative Perinatal Neonatal Network (NCPNN). Stepwise Logistic Regression was performed to determine CS correlates.

RESULTS

The rate of CS was 26.4% and correlated with socio-demographic, obstetrical and provider-related variables. Regression analysis identified age, paternal occupation, mode of payment, parity, birth weight, gestational age, multiple pregnancies, adequate prenatal care, complications during pregnancy, body mass index at delivery, hospital teaching status, day of the week and year of delivery to be significant correlates of CS.

CONCLUSION

This study shows an increased CS rate in a middle-income country, and identifies the correlates of women delivering by the abdominal route. These correlates may be used for effective reduction policies in the future.

Caesarean or vaginal delivery for preterm very-low-birth weight (≤1,250 g) infant: experience from a district general hospital in UK

OBJECTIVE

To determine whether delivery by caesarean is associated with a better neuro-developmental outcome at two years for preterm infants born weighing 1,250 g or less.

SETTING

District General Hospital, United Kingdom.

DESIGN

All inborn infants weighing <1,250 g born at St Helier University Hospital between January 1995 and December 2003 were identified from contemporaneously collected computer database. All hospital records were retrieved. Details of the mother, delivery route, Apgar score, details of resuscitation and details of the baby, neonatal progress and neuro-developmental status at two years was transcribed on a pre-designed proforma. Neuro-developmental status assessment at two years of age was carried out by an independent neurodevelopmental paediatrician. Neuro-developmental status was classified as normal, severe, moderate or mild disability.

STATISTICAL ANALYSIS

Analysis was done by creating a simple two by two table. Statistical significance was set at p = 0.05. Multivariate and univariate analysis was carried out for a number of confounding variables.

SAMPLE

Total of 411 babies were identified from the data-base. Of these 59 were still born and fourteen though born alive died in the delivery suit. 125 (37%) were excluded from analysis as they were returned to their referring hospitals prior to discharge from hospital. Information about their two-year follow-up was either incomplete or not robust enough to be included in the analysis. Analysis was carried out on 213(63%) for whom we had complete data set at two years of age (103 infants born via vaginal delivery and 110 infants were born by caesarean section).

OUTCOME MEASURE

Primary outcome measure was to compare survival at discharge and neurodevelopmental status at two years of age of this cohort. Secondary outcome included determining the incidence of grade III or IV intraventricular haemorrhage (IVH), chronic lung disease and necrotising enterocolitis (NEC).

RESULTS

The overall caesarean delivery rate for this cohort was 51.6% while the overall caesarean rate for all births at our hospital during the study period varied between 20 and 23%. Neonatal mortality for those delivered by caesarean was 12.7% compared to 14.5% for those delivered vaginally (p = ns). Overall incidence of any neuro-disability at two years of age was 46.8% for those delivered by caesarean compared to 47.7% for those delivered vaginally (p = ns). There was no difference in those with severe (23.5% vs. 25.0%), moderate (10.4% vs. 9%) or mild (12.5% vs. 13.6%) neuro-disability between the groups nor was there any difference in the number of babies with IVH, chronic lung disease and NEC. Neuro-disability was equally greater in both groups for babies born weighing 750 grams or less and/or born at 26 weeks or less gestation.

CONCLUSION

Despite the increasing tendency to deliver extremely preterm babies by caesarean, we did not find that it was associated with either reduced mortality or neuro-disability at two years of age. Therefore the method of delivery of very-low-birth weight premature infants should be based on obstetric or maternal indications rather than the perceived outcome of the baby.

The association of the composite IL-1 genotype with periodontitis progression and/or treatment outcomes: a systematic review

BACKGROUND

Genetically transmitted traits such as cytokine gene polymorphisms may accentuate the host inflammatory response to the bacterial challenge and influence susceptibility to periodontitis.

OBJECTIVE

To systematically review the evidence of an association between the interleukin-1 (IL-1) composite genotype, i.e. presence of the allele 2 in the gene clusters IL-1A-889 and in IL-1B +3953, and periodontitis progression and/or treatment outcomes.

MATERIAL AND METHODS

Based on the focused question, a search was conducted for longitudinal clinical trials comparing progression of periodontitis and/or treatment outcomes in IL-1 genotype-positive (carrying allele 2) and IL-1 genotype-negative (not carrying allele 2) subjects. A search in the National Library of Medicine computerized bibliographic database MEDLINE and a manual search were performed. Selection of publications, extraction of data and validity assessment were made independently by two reviewers.

RESULTS

The search provided 122 titles of which 11 longitudinal publications were included. The heterogeneity of the data prevented the performance of a meta-analysis. While findings from some publications rejected a possible role of IL-1 composite genotype on progression of periodontitis after various therapies, other reported a prognostic value for disease progression of the positive IL-1 genotype status. When assessed on a multivariate risk assessment model, several publications concluded that the assessment of the IL-1 composite genotype in conjunction with other covariates (e.g. smoking and presence of specific bacteria) may provide additional information on disease progression. The small sample size of the available publications, however, requires caution in the interpretation of the results.

CONCLUSION

Based on these findings, (i) there is insufficient evidence to establish if a positive IL-1 genotype status contributes to progression of periodontitis and/or treatment outcomes. Therefore, (ii) results obtained with commercially available tests should be interpreted with caution.

Mode of delivery in the early preterm infant (<28 weeks)

Elective caesarean section for women in labour with an immature baby might reduce the chances of fetal or neonatal death, but might also increase the risk of maternal morbidity. A review (updated in February 2004) of randomised trials comparing a policy of elective caesarean section versus expectant management with recourse to caesarean section produced six studies involving only 122 women. Differences in fetal outcome did not reach significance, but mothers undergoing elective caesarean section were more likely to have serious morbidity. Scientifically, the evidence remains inadequate. Clinically, the recommendation is that prematurity is not, in itself, an indication for caesarean section. In a survey from Israel, published in December 2004, of 2955 very low birthweight infants born at 24-34 weeks of gestation, the overall caesarean section rate was 51.7%, and the mortality rate among babies prior to discharge was lower after caesarean section (13.2 versus 21.8%). After adjustment using multiple logistic regression, caesarean section had no effect on survival except in a subgroup with amnionitis, and it was again concluded that caesarean section cannot be routinely recommended unless there are other indications. A decision model developed in the USA has compared costs and health outcomes of two options for managing labour at 24 weeks of gestation. The probabilities of both intact survival (16.8 versus 12.9%) and survival with major morbidity (39.2 versus 19.4%) are higher with willingness to perform caesarean section, but less aggressive management is the more cost-effective strategy. Large studies are few and recruitment to such studies is perceived as a major problem. For clinicians, the decision will be influenced by local circumstances.

Increased intrauterine frequency of Ureaplasma urealyticum in women with preterm labor and preterm premature rupture of the membranes and subsequent cesarean delivery

OBJECTIVE

The purpose of this study was to evaluate the prevalence of microbial invasion of the amniotic cavity at the time of preterm cesarean delivery for therapy-resistant preterm labor or preterm premature rupture of membranes, which are events that commonly are induced by infection, and to compare this group of patients with a group of patients who underwent preterm cesarean delivery for indications other than preterm labor or preterm premature rupture of membranes.

STUDY DESIGN

We studied 207 consecutive women between 23 and 34 weeks of gestation who underwent cesarean delivery. These patients were divided into 3 groups according to the indication for cesarean delivery: patients with preterm labor (group 1), patients with preterm premature rupture of membranes (group 2), and patients with other indications (group 3). In the course of the surgical procedure, amniotic fluid, amniotic membrane, and placental tissue specimens were collected for the detection of pathogens.

RESULTS

Ureaplasma urealyticum was detected in 43.9% (58/132) of the patients of groups 1 and 2, with no significant difference between these 2 subgroups. In group 3, which served as the comparison group, Ureaplasma urealyticum was isolated in only 2.7% (2/75) of the patients. Ureaplasma urealyticum as a single pathogen was more frequent than all obligate pathogens together (43.9% vs 39.3%).

CONCLUSION

Our results provide evidence for an association between intrauterine colonization with Ureaplasma urealyticum and both therapy-resistant preterm labor and preterm premature rupture of membranes.

What’s new and novel in obstetric anesthesia? Contributions from the 2003 scientific literature

THE PREGNANT PATIENT: Age; maternal disease; prophylactic antibiotics; gastroesophageal reflux; obesity; starvation; genotyping; coagulopathy; infection; substance abuse; altered drug responses in pregnancy; physiological changes of pregnancy. THE FETUS: Fetal monitoring; intrauterine surgery. THE NEWBORN: Breastfeeding; maternal infection, fever, and neonatal sepsis evaluation. OBSTETRIC COMPLICATIONS: Embolic phenomena; hemorrhage; preeclampsia; preterm delivery. OBSTETRIC MANAGEMENT: External cephalic version and cervical cerclage; elective cesarean delivery; fetal malpresentation; vaginal birth after cesarean delivery; termination of pregnancy. OBSTETRIC ANESTHESIA: Analgesia for labor and delivery; anesthesia for cesarean delivery; anesthesia for short obstetric operations; complications of anesthesia. MISCELLANEOUS: Consent; ethics; history; labor support; websites/books/leaflets/journal announcements.

Towards improved neonatal outcome: future strategies

The role of the obstetrician is to help predict and prevent maternal/fetal infection/inflammation related to neonatal mortality and morbidity. Predictive studies have mainly focused on the high-risk phenotype. Currently, there is a scientific drive to analyse the genetic susceptibility of preterm birth (PTB). Studies of the combination of environmental and lifestyle risk factors with the known genotype may result in a better understanding of the causation of PTB. Predictive technical markers such as fibronectin, cervical length measurement and home uterine activity remain largely unproven. Current antenatal care has not achieved primary prevention of PTB. Tocolytics and antibiotics constitute the two key elements of secondary prevention. Tocolytics have a minimal benefit but should not be used to prolong an infected preterm pregnancy. The use of antibiotics in preterm premature rupture of membranes can prolong the pregnancy with a decrease in neonatal morbidity. Anti-inflammatory cytokines, cytokine inhibitors and soluble cytokine receptors are promising treatment options that could modulate the intra-amniotic inflammatory process.

Perspectives in the prevention of premature birth

Obstetric and neonatal interventions have improved the survival of preterm infants, but there has not been an equivalent reduction in long-term neurological disability. Thus, some effort must be invested in finding ways of preventing preterm birth. Numerous programmes have been promoted to address the matter of how the frequency of preterm birth could be prevented. Most interventions intended to prevent preterm labour do not have the desired effect, except for antibiotic treatment in cases of asymptomatic bacteriuria or bacterial vaginosis and progesterone administered prophylactically in high-risk women. Tocolytic drugs appear to delay delivery long enough for successful administration of corticosteroids in women in preterm labour, but without decreasing the risk of preterm birth. Some authors promote public health approaches that address all risk factors and affect the entire population of pregnant women, given that prevention programmes directed only at high-risk women have had little effect in preventing preterm births. However, the lack of progress in reducing the frequency of preterm births is also due to our limited understanding of the aetiology of preterm delivery. Although there is growing evidence that infection and neuroendocrine processes are involved, progress has remained slow. Recently, the hypothesis of a genetic predisposition to preterm delivery has been set up. Additional research exploring the pathophysiology of preterm labour is obviously needed, which will hopefully lead to the development of new therapeutic approaches.

Handicap neuro-sensoriel grave de l’enfant grand prématuré

OBJECTIVE

Advances in perinatal care have resulted in a sharply increasing survival rate among very preterm infants. However, there is some concern about the later neurodevelopmental outcome of those infants who survive. In this paper, we review the prevalence estimates of motor (cerebral palsy), sensorineural and cognitive impairments and their recent time-trends in very preterm infants.

METHOD

A review of studies describing neurodevelopmental outcome of very preterm infants in Europe, Australia and America North.

RESULTS

The gestational age-specific prevalences of cerebral palsy (CP) were 72-86 for extremely preterm children (<28 weeks), 32-60 for very preterm (28-31 weeks) and 5-6 for moderate preterm (32-36 weeks), and 1.3-1.5 for term children per 1000. The live birth prevalence for CP remained unchanged in extremely and very preterm infants since 1990. The prevalence estimates of moderate and severe cognitive impairments are 15 to 25% in very preterm children. Less than 4% of very preterm infants develop severe hearing or visual loss.

CONCLUSION

This review indicates that very preterm infants have high risk of disability. Most studies have been conducted between 1985 and 1995. Thus, these results should be interpreted with caution before generalisation to recent cohorts.

Évaluation des risques en anténatal, information des parents et prise en charge de l’accouchement

Perinatal networks, antenatal administration of glucosteroids, postnatal administration of surfactant, and new techniques for mechanical ventilation, have considerably improved the prognosis of extremely preterm infants. Such recent progress in perinatology had enabled neonatologists to provide intensive care for infants born after 24 and 28 weeks of gestation. This practice raises serious medical and ethical issues. The optimal mode of delivery of such newborns is not well established mainly because available studies are retrospective and subjected to biases. Moreover, perinatologists are implicated in the continuing discussion on ethical issues that modify clinical practices.