Publications

Abstract

The aim of this review is to gather the most recent data on the association between intrauterine inflammation and neurodevelopmental disorders in preterm infants. Two major methodological challenges will be emphasized: first, the heterogeneity of definitions of intrauterine inflammation; and second, the heterogeneity of study populations, in which the causes of preterm birth (spontaneous labor, preterm premature rupture of membranes, maternal hypertensive disorders, etc.) are not always distinguished. These elements introduce a risk of confounding bias and partly explain the divergence between studies. In the short term, intrauterine inflammation is associated with an increased risk of early-onset sepsis and necrotizing enterocolitis. However, the effects on respiratory and neurological outcomes are less clear, and whether an association exists remains controversial. In the longer term, in populations homogeneous with respect to the cause of prematurity, clinical chorioamnionitis has been associated with an increased risk of cerebral palsy at 2 years, a risk further amplified when combined with histological chorioamnionitis. However, this risk of cerebral palsy does not appear to persist beyond 5 years, and no major association has been reported on cognitive, sensory, coordination, or behavioral functions. Regarding isolated histological chorioamnionitis, most studies conducted on homogeneous populations do not report an association with neurodevelopmental disorders. Nevertheless, some suggest that severe inflammation, particularly in the presence of a fetal inflammatory response, may increase the risk of neurodevelopmental impairment. In conclusion, while intrauterine inflammation is associated with increased neonatal morbidity, its long-term impact on neurodevelopment appears limited and dependent on the severity of the inflammation. These findings highlight the importance of conducting longitudinal studies on homogeneous populations to refine our understanding of developmental trajectories in preterm infants.

Abstract

Retrospective foreign studies conducted using data from medical-administrative registers have all reported an increase in neonatal mortality and morbidity associated with vaginal delivery, mainly for the second twin. However, these studies suffer from major methodological flaws: lack of comparison according to the planned route of delivery, difficulty in distinguishing extreme prematurity from moderate or late prematurity, lack of adjustment for the most important confounding factors, so that their results do not allow any conclusion regarding a protective effect of cesarean section. Conversely, 3 high-quality French studies, including 2 prospective studies, report no benefit associated with cesarean section in women with preterm labor or premature rupture of membranes. In these 3 studies, even if the differences are not significant, severe neonatal morbidity is lower or survival without severe neonatal morbidity is higher in the planned vaginal delivery group compared to the planned cesarean group. In conclusion, there is no scientific evidence to support any protective effect of elective caesarean section in cases of spontaneous prematurity before 32 weeks of gestation. Therefore, planned vaginal delivery should be the preferred option in France.

Abstract

Extremely premature infants (22-26 weeks) are at high risk of neonatal death, severe morbidity, and disability. The survival of these infants is essentially linked to the obstetrical-pediatric team’s willingness to provide intensive care. Numerous studies show that this increased survival rate in cases of willingness to actively manage them is not accompanied by an increased risk of morbidity and psychomotor delay in the longer term. The great variability in antenatal practices for the management of extremely premature infants reflects the confusion among medical teams who, in the absence of consensus and formalized decision-making processes, end up making management decisions that are at best based on local habits, and at worst on the individual habits of the attending clinician. This variability in practices across centers poses a problem of equity. Thus, in our country, practices and outcomes vary greatly depending on the child’s place of birth. Intensive antenatal care rates for these children vary from 22 to 61% depending on the region. One consequence is a survival rate in France that is much lower than in other countries. Survival in the USA, Great Britain, Japan, Australia, and Sweden is 10 to 50% higher than in France. To improve this situation, new principles have been proposed: administration of corticosteroid therapy independently of treatment, prognostic assessment not based solely on gestational age, and collective decision-making on treatment outside of an emergency setting, and consensus on the information to be provided to parents before informing them and seeking their opinions. This approach requires consistency in care before, during, and after birth and relies on close obstetric-pediatric collaboration. This new organization is being tested in the PREMEX Cluster randomized trial involving 25 perinatal networks in France, the results of which will be available in 2026.

Abstract

Objective: To explore term mortality rates in relation to rates of early-term birth (gestational ages 37 + 0 to 38 + 6 weeks), regarded as a proxy indicator of practices of elective birth by induction or caesarean.

Design: Ecological study using national birth data.

Setting: 28 European countries.

Population: Births ≥ 37 weeks between 2015 and 2020.

Methods: Aggregated data on live and stillbirths by completed week of gestation was compiled from routine sources in the Euro-Peristat network. Countries were divided into three groups based on their percentages of early-term births using terciles (high, medium and low) and mortality rates were compared between groups with random-effects meta-analysis of proportions.

Main outcome measures: Stillbirths (antepartum or intrapartum fetal death) and perinatal death (stillbirth or early neonatal death) per 1000 total births ≥ 37 weeks.

Results: Early-term birth rates ranged from 17.8% (Iceland) to 49.1% (Cyprus), with terciles being < 21%, 21%-27%, and > 27%. Post-term birth rates were low in countries with higher early-term birth rates. The pooled stillbirth rate ≥ 37 weeks was 1.28 per 1000 total births (95% CI: 1.13-1.46) in the lowest tercile and 1.05 (95% CI: 0.95-1.16) in the highest (p = 0.05), but prediction intervals were wide reflecting heterogeneity within groups. No evidence of difference was seen between perinatal mortality rates by tercile (p = 0.71).

Conclusion: On average, the stillbirth rate was lower in countries where early-term birth rates were highest, but no difference was found in perinatal mortality rates. Heterogeneity was high within groups.

Abstract

The incidence of haematological malignancies during pregnancy ranges from 4·0 to 15·8 cases per 100 000 pregnancies, with Hodgkin lymphoma, acute leukaemia, and aggressive B-cell non-Hodgkin lymphoma being the most frequent subtypes. Although survival rates are similar to those in patients who are not pregnant with similar disease profiles, pregnant women face higher risks of maternal morbidity, along with adverse obstetric and neonatal outcomes. Their management, therefore, requires a carefully balanced approach that minimises obstetric risks and ensures effective oncological control. Physiological adaptations of pregnancy can obscure the clinical presentation of sepsis, modulate the course of infections, and, through altered pharmacokinetics, complicate antimicrobial therapy. Safety data on antimicrobials are scarce and concerns about teratogenicity further constrain therapeutic decisions. As a result, infection management in pregnant women requires tailored approaches to diagnosis, antimicrobial therapy, and fetal monitoring. This Review summarises the physiological changes influencing infection risk and treatment efficacy in pregnant women with haematological malignancies; it outlines key challenges in prevention and management and identifies crucial knowledge gaps to guide practice and research in this complex interplay.

Abstract

Importance: Progress in perinatal care has improved survival for children born very preterm (VPT), but these children remain at higher risk of cognitive impairment compared with children born at term.

Objective: To synthesize cohort studies on childhood cognitive ability following VPT birth to investigate trends over time.

Data sources: All studies from 5 previous meta-analyses of VPT birth and cognition published before 2019 were included, and PubMed, Web of Science, and PsycInfo were searched for new studies published up to June 2024.

Study selection: Studies reporting IQ scores of children (aged <18 years) born VPT (<32 weeks’ gestational age [GA] or birth weight <1500 g) with a term-born comparison group were included.

Data extraction and synthesis: Two reviewers independently selected studies, extracted data, and evaluated study quality using a modified version of the Newcastle-Ottawa Scale. Unique cohorts were identified to avoid duplicate measures from studies on the same children.

Main outcomes and measures: The standardized mean difference (SMD) of IQ scores between VPT-born and term-born children was calculated, and mixed-effects metaregression was used to investigate linear and nonlinear associations between median birth year and the SMD. The main analysis focused on cohorts with IQ measured between 4 and 7 years of age to allow comparison at similar assessment ages. Secondary analyses were conducted in all cohorts using IQ obtained at the latest assessment age.

Results: A total of 257 studies reported data from 131 cohorts of 25 746 individuals born from 1977 to 2016 (15 548 born VPT and 10 198 at term). In the 61 cohorts assessed at age 4 to 7 years (13 842 children born between 1977 and 2014 [8847 born VPT and 4995 at term]; mean [SD] GA, 28.2 [1.7] weeks for the VPT cohorts), IQ was lower for VPT-born children compared with term-born children (SMD = -0.88; 95% CI, -0.97 to -0.79). The linear model showed no association with birth year (β = -0.002; 95% CI,-0.012 to 0.008). Three types of nonlinear models were fit, with no nonlinear associations observed. Adjustment for GA and study characteristics did not change the results (β = -0.001; 95% CI, -0.013 to 0.011). Secondary analysis of 131 cohorts found a similar difference between VPT and term groups (SMD = -0.84; 95% CI, -0.90 to -0.79), with no time trend (β = 0.001; 95% CI, -0.005 to 0.007).

Conclusions and relevance: On average, children born VPT had significantly lower IQ scores than term-born children, and this deficit did not decrease in studies conducted over 4 decades

Abstract

Background: Lower gestational age (GA) is linked to higher mortality and morbidity. Long-term health and developmental difficulties of individuals born moderate (MPT, 32-33 GA) and late (LPT, 34-36 GA) preterm, and early term (ET, 37-38 GA) are less explored than those of their very preterm peers.

Objectives: To test how being born MPT, LPT, or ET affects health and development at age 10, compared to full-term (FT, 39-40 GA) births.

Methods: Data from two ongoing French nationwide birth cohorts, initiated in 2011, were collected at 10 years via telephone interview (n = 8372) and home visit (n = 6418). Weighting procedures accounted for study design, non-inclusion, and participation. Outcome-wide regressions (modified Poisson, linear), adjusted for socioeconomic situation and pregnancy complications, were used to calculate adjusted relative risks (aRR) and beta-coefficients (β).

Results: No increased risk of asthma/atopy was observed for our MPT, LPT, and ET populations, except for allergic rhinitis in MPT. Strabismus was more prevalent among MPT, LPT, and ET (2.3%-3.0%) than FT (1.3%), corresponding to aRR of 1.99 (95% CI 0.91, 4.39), 1.67 (95% CI 0.85, 3.28), and 2.18 (95% CI 1.37, 3.47), respectively. MPT and LPT had increased risk of balance problems, with aRR of 1.63 (95% CI 0.81, 3.32) and 1.80 (95% CI 1.14, 2.82), respectively. MPT scored on average lower on the WISC-V full-scale IQ Matrix β = -0.6 (95% CI -1.17, -0.11) and performance IQ Puzzle β = -0.7 (95% CI -1.23, -0.26) subtests, compared to FT, and had an increased risk of dental malposition, aRR = 1.42 (95% CI 1.15, 1.75).

Conclusions: While most outcomes (respiratory, anthropometry, cardiometabolic) did not differ between MPT, LPT, ET, and their FT peers, others, including strabismus, were more prevalent among preterm and ET. Some outcomes were specific to MPT, including lower WISC-V average scores and dental issues.

Abstract

Background: Long-term effects of Skin-to-Skin Contact (SSC) on neurodevelopmental outcome for preterm children are still debated. We aimed to evaluate associations between SSC, cognition and behavior at 5 years among children born at 24-31 weeks of gestation.

Methods: In this secondary analysis of the French Etude Epidémiologique sur les Petits Ages Gestationnels (EPIPAGE-2), a nationwide prospective population-based cohort study conducted in all neonatal units across 25 French regions from Mar 28, 2011, to Dec 31, 2011, we examined preterm-born children divided into two groups based on exposure to skin-to-skin contact (SSC) during the first week of life. Outcomes at 5 years included full-scale intelligence quotient (FSIQ; Wechsler Preschool and Primary Scale of Intelligence, 4th edition) and behavioural difficulties (Strengths and Difficulties Questionnaire, SDQ), using a contemporaneous group of term-born children from the ELFE cohort as a reference. The ELFE cohort enrolled participants during four inclusion periods in 2011: Apr 01-04, 2011; Jun 27-Jul 04, 2011; Sep 27-Oct 04, 2011; and Nov 28-Dec 05, 2011. Included children were born at 24-31 weeks of gestation, remained in the same neonatal unit during the first week of life, were alive at 7 days, had no severe cerebral malformations or decisions to limit/withhold care, and had data on SSC exposure. Results are given after multiple imputation using propensity score methods with inverse probability of treatment weighting approach.

Findings: Of 3669 live-born preterm children, 2726 children were eligible and 2666 included with SSC information during the first week of life available; 2561 survived to 5 years (1328 boys (51.8%). Among survivors, 1581 received SSC during the first week of whom 987 had full follow-up assessment; 980 were not exposed of whom 558 had full follow-up assessment. SSC exposure increased with gestational age (21.7% at 24 weeks to 78.0% at 31 weeks), with variability across neonatal units (range 5%-100%). Compared with non-exposed children, exposed children had higher FSIQ scores (mean difference +2.3, 95% CI [+0.3 to 4.3], p = 0.024) and were more likely to score ≥-1 standard deviation (odds ratio 1.33, 95% CI [1.04-1.70], p = 0.023). There was no significant difference in SDQ scores between groups (mean difference -0.3, 95% CI [-1.1 to 0.5], p = 0.42 and score ≥90th percentile odds ratio 0.92 [0.64; 1.33], p = 0.66).

Interpretation: While the duration of SSC the first week of life and SSC beyond the first week were not accounted for, our findings suggest that SSC during the first week of life may be associated with an increased likelihood of higher FSIQ at 5 years. These results point to a potential neuroprotective role of SSC during this early sensitive postnatal period and highlight important areas for improvement. Variability in SCC implementation across units deserves attention and further research is needed to explore dose-response relationships and timing effects.

Funding: The National Research Agency (via the French Equipex Program of Investments in the Future); the French Institute of Public Health Research/Institute for Public Health and its partners at the French Health Ministry; the National Institute of Cancer; the National Institute of Health and Medical Research; the National Solidarity Fund for Autonomy; and the PremUP Foundation.

Abstract

Objective: To investigate the magnitude and evolution of inequalities in neonatal mortality rates by using area based socioeconomic indices in France.

Design: National population based study.

Setting: For 2015-20, data from the French National Health Data System (Système National des Données de Santé, SNDS). For 2001-08, neonatal death certificates and aggregate vital statistics data by municipality of residence.

Participants: Live births with a gestational age ≥22 completed weeks to a mother residing in metropolitan France, 2015-20 (4 293 403 live births and 10 869 neonatal deaths), compared with a 2001-08 study (6 202 918 live births and 14 851 neonatal deaths).

Main outcome measures: Differences in neonatal mortality rate (death before day 28 of life) according to the socioeconomic characteristics of the mother’s municipality of residence. Comparison with data from a 2001-08 study to assess changes in socioeconomic inequalities and their contribution to the increase in neonatal mortality rate.

Results: The neonatal mortality rate was 2.53 per 1000 live births in 2015-20. Five indicators, previously associated with perinatal mortality, were combined into a perinatal French deprivation index (P-FDep) for the main analysis. P-FDep was categorised into five equal groups (deprivation groups 1-5) for comparison with other research and into 10 equal groups (deprivation groups 1-10) for more granular analyses, with group 1 being the least and group 5 (or group 10) the most deprived group. The rate in the most deprived compared with the least deprived group for P-FDep was 1.71 (95% confidence interval 1.60 to 1.83) times higher, based on the analysis of deprivation groups 1-5. A mortality gradient existed across the groups, translating into 2496 excess deaths (23.3%) when the rate in the least deprived group was applied to all areas. The gradient was more marked when deprivation groups 1-10 were used (relative risk 1.88, 95% CI 1.71 to 2.07 for the highest to the lowest deprived group). Compared with 2001-08 (neonatal mortality rate 2.39 per 1000), the rate remained constant in the least deprived areas, but worsened in the most deprived areas (+10.1% and +11.7% for groups 4 and 5, respectively), increasing the relative risks between the highest and lowest groups, which were 1.54 (95% CI 1.46 to 1.62) for deprivation groups 1-5 and 1.67 (1.55 to 1.79) for deprivation groups 1-10, in 2001-08.

Conclusions: In this study, the socioeconomic level of the mother’s place of residence was strongly associated with the neonatal mortality rate. The data showed that inequalities have widened, contributing to the increase in the neonatal mortality rate.

Abstract

Mother’s own milk is the preferred source of nutrition for preterm infants due to its beneficial compounds, including human milk oligosaccharides (HMOs). HMOs support microbiota and immune development, but their effect on the preterm brain remains unstudied. Here, we examined the therapeutic potential of HMOs and short-chain galacto- and long-chain fructo-oligosaccharides (scGOS/lcFOS) in a preclinical model for encephalopathy of prematurity. Pregnant Wistar rats were injected with 10 μg/kg lipopolysaccharides at embryonic day 20, and pups were exposed to hypoxia (8% O₂, 140 min) at postnatal day (P)4 (fetal inflammation and postnatal hypoxia; FIPH). From P1, FIPH-pups of both sexes were treated intragastrically with HMOs, scGOS/lcFOS (9:1), or water. Transcriptomic analysis of CD11b/c + microglia was performed at P6, while immunohistochemical, microbial and short-chain fatty acid (SCFA) analyses were performed at P20. Decreased cortical myelin in FIPH animals was rescued exclusively by HMOs. Furthermore, both HMOs and scGOS/lcFOS treatments normalized reduced parvalbumin+ interneuron numbers in the hippocampus, potentially through promoting beneficial bacteria, including Lactobacillus and Bifidobacterium, and cecal acetic acid content. Interestingly, treatment with HMOs more effectively restored FIPH-induced upregulation of microglial genes associated with immune activation and normalized persistent activated microglial morphology in FIPH-males. HMOs supplementation holds promise to improve neurodevelopmental outcomes following preterm birth.