Predictors of cerebral palsy in very preterm infants: the EPIPAGE prospective population-based cohort study

AIM

The aim of this study was to assess the independent role of cerebral lesions on ultrasound scan, and several other neonatal and obstetric factors, as potential predictors of cerebral palsy (CP) in a large population-based cohort of very preterm infants.

METHOD

As part of EPIPAGE, a population-based prospective cohort study, perinatal data and outcome at 5 years of age were recorded for 1812 infants born before 33 weeks of gestation in nine regions of France in 1997.

RESULTS

The study group comprised 942 males (52%) and 870 females with a mean gestational age of 30 weeks (SD 2 wks; range 24-32 wks) and a mean birthweight of 1367 g (SD 393 g; range 450-2645 g). CP was diagnosed at 5 years of age in 159 infants (prevalence 9%; 95% confidence interval [CI] 7-10%), 97 males and 62 females, with a mean gestational age of 29 weeks (SD 2 wks; range 24-32 wks) and a mean birthweight of 1305 g (SD 386 g; range 500-2480 g). Among this group, 67% walked without aid, 14% walked with aid, and 19% were unable to walk. Spastic, ataxic, and dyskinetic CP accounted for 89%, 7%, and 4% of cases respectively. The prevalence of CP was 61% among infants with cystic periventricular leukomalacia, 50% in infants with intraparenchymal haemorrhage, 8% in infants with grade I intraventricular haemorrhage, and 4% in infants without a detectable cerebral lesion. After controlling for cerebral lesions and obstetric and neonatal factors, only male sex (odds ratio [OR] 1.52; 95% CI 1.03-2.25) and preterm premature rupture of membranes or preterm labour (OR 1.72; 95% CI 0.95-3.14) were predictors of the development of CP in very preterm infants.

INTERPRETATION

Cerebral lesions were the most important predictor of CP in very preterm infants. In addition, infant sex and preterm premature rupture of membranes or preterm labour were also independent predictors of CP.

Very preterm birth: who has access to antenatal corticosteroid therapy?

We describe the administration of antenatal corticosteroid therapy (ACT) for liveborn very preterm neonates in a population-based study. A total of 790 very preterm neonates (between 24 and 31 full weeks of gestation) were included in this regionally defined population of very preterm neonates in France. The main outcome measure was non-access to ACT. Data were analysed using logistic and polytomous models to control for neonatal and sociodemographic characteristics, mechanisms of very preterm birth and neonatal network organisation. As compared with level III, births in levels I-II maternity units were closely related to non-access to ACT (60.1% vs. 8.8%), but not to pregnancy follow-up (19.7% vs. 17.8%). Only 6.3% of very preterm neonates that benefited from antepartum referral did nor receive ACT. Births associated with rupture of membranes and gestational hypertension were significantly more often transferred to level-III units (73.8% and 68.3% respectively) than those due to maternal bleeding and spontaneous labour (57.0% and 50.7% respectively), and the neonates had a lower probability of not receiving ACT (8.5%, 11.5%, 23.0%, 31.2% respectively). Very preterm neonates referred in utero to a level-III unit came from a more favourable socio-economic environment. Non-access to ACT was more often observed in neonates born to 14- to 24-year-old mothers, smokers, of low socio-economic status, and preterm birth resulting from maternal bleeding or spontaneous labour. These data from a French regional study show that access to ACT is not only explained by practitioners' support of recommendations. In our population-based study, ACT access was related to socio-economic factors and to the mechanisms of very preterm birth. Improving the rate of access to ACT should take these organisational, medical and socio-economic dimensions into account.

[Very preterm birth: is maternal anesthesia a risk factor for neonatal intubation in the delivery room?]

OBJECTIVE

To assess the risk of tracheal intubation at birth in very premature neonates related to the type of maternal anesthesia in case of elective cesarean.

POPULATION AND METHODS

All 219 live-born very premature neonates (28-32 weeks of gestation), delivered after an elective cesarean in the 27 maternity wards of 2 French semi-rural neonatal networks. Eighty-three percent (182/219) were delivered in level III maternity wards in university hospitals.

RESULTS

Of the very preterm neonates, 33.3% (73/219) were intubated in the delivery room, either for respiratory distress syndrome or a low APGAR score. Very preterm neonates delivered after maternal general anesthesia were more often intubated than those delivered after spinal anesthesia (48.7% vs 25.2%; OR: 2.8; 95% CI: 1.8-5.1). The risk of intubation related to maternal general anesthesia remained statistically significant after an adjustment for gestational age, fetal growth retardation, respiratory distress syndrome, type of maternity ward, and a propensity score that took into account maternal sociodemographic characteristics and the causes of very preterm birth (aOR: 3.4; 95% CI: 1.4-8.2). The risk of intubation related to general anesthesia was lower after adjusting for the 5-min APGAR score (aOR: 2.8; 95% CI: 1.0-7.3).

CONCLUSION

Very preterm neonates delivered after cesarean with general anesthesia require tracheal intubation in the delivery room more often than those delivered with spinal anesthesia. This study cannot assess a causal link between anesthesia and the need for neonatal intubation. However, neonatologists have to be aware of the type of maternal anesthesia because it may interfere with the non-invasive ventilation support policy of the very preterm neonate.

Behavioral problems and cognitive performance at 5 years of age after very preterm birth: the EPIPAGE Study

OBJECTIVES

We compared the frequency of behavioral problems in very preterm and term children at 5 years of age. We hypothesized that behavioral problems would be associated with cognitive impairment and environmental factors and that differences between the 2 groups would be reduced but persist after adjusting for cognitive performance and environmental factors.

PATIENTS AND METHODS

The Etude Epidémiologique sur les Petits Ages Gestationnels (EPIPAGE) study was a prospective population-based cohort study that included all births occurring between 22 and 32 weeks' gestation and a control group of infants born at 39 to 40 weeks' gestation in 1997 in 9 French regions. Neonatal and obstetrics data were collected at birth. At 5 years of age, sociodemographic status and neurodevelopmental and cognitive development of the children, as well as maternal mental well-being, were assessed. The behavioral problems of 1102 very preterm and 375 term singletons without major impairments were studied by using the parent-completed Strengths and Difficulties Questionnaire.

RESULTS

Parents of very preterm children reported significantly more behavioral problems, with a twofold higher prevalence compared with term children for hyperactivity/inattention, emotional symptoms, and peer problems. Behavioral problems were associated with low cognitive performance, developmental delay, hospitalizations of the child, young maternal age, and poor maternal mental well-being. Very preterm children were still at higher risk of behavioral problems compared with term children after adjustment for cognitive performance and all others factors.

CONCLUSIONS

Behavioral problems were strongly related to cognitive impairment, but very preterm children were still at higher risk even after adjusting for cognitive performance. Early screening for behavioral problems should be encouraged for all very preterm children, and maternal well-being should also be the focus of special attention.

Can birth weight standards based on healthy populations improve the identification of small-for-gestational-age newborns at risk of adverse neonatal outcomes?

OBJECTIVES

To develop neonatal growth standards based on (1) the entire population of live births and (2) a healthy subpopulation and compare them in identifying infants as small for gestational age and at risk of adverse neonatal outcomes.

PATIENTS AND METHODS

We included all births, between 28 and 41 weeks of gestation, reported in Burgundy (France) from 2000 to 2006. Fetal deaths, multiple births, and chromosomal aberrations were excluded. We first estimated separate birth weight distributions at each week of gestation for (1) all neonates and (2) only infants born from women without maternal diseases. Small for gestational age was defined as a birth weight below the 10th percentile of the corresponding standard. We assessed the associations of small for gestational age on the basis of the alternative definitions, with mortality and major neonatal outcomes.

RESULTS

We included 127 584 live births. For term newborns, small for gestational age was significantly associated with an increased risk of death with both standards. In contrast, for preterm newborns (32-36 weeks), small for gestational age was not significantly associated with mortality and morbidity. Very preterm infants (28-31 weeks) identified as small for gestational age according to the healthy-population standard were at higher risk of chronic lung disease and intraventricular hemorrhage. When using the entire-population standard, small for gestational age was associated with chronic lung disease but not intraventricular hemorrhage. The area under the receiver operating characteristic for predicting an intraventricular hemorrhage was significantly greater for small for gestational age defined with the healthy-population standard compared with small for gestational age classified with the entire-population standard.

CONCLUSIONS

Neonatal growth standards based on healthy populations could improve the identification of very preterm neonates as small for gestational age and at risk of intraventricular hemorrhage.

Neurodevelopmental disabilities and special care of 5-year-old children born before 33 weeks of gestation (the EPIPAGE study): a longitudinal cohort study

BACKGROUND

The increasing survival rates of children who are born very preterm raise issues about the risks of neurological disabilities and cognitive dysfunction. We aimed to investigate neurodevelopmental outcome and use of special health care at 5 years of age in a population-based cohort of very preterm children.

METHODS

We included all 2901 livebirths between 22 and 32 completed weeks of gestation from nine regions in France in Jan 1-Dec 31, 1997, and a reference group of 667 children from the same regions born at 39-40 weeks of gestation. At 5 years of age, children had a medical examination and a cognitive assessment with the Kaufman assessment battery for children (K-ABC), with scores on the mental processing composite (MPC) scale recorded. Data for health-care use were collected from parents. Severe disability was defined as non-ambulatory cerebral palsy, MPC score less than 55, or severe visual or hearing deficiency; moderate deficiency as cerebral palsy walking with aid or MPC score of 55-69; and minor disability as cerebral palsy walking without aid, MPC score of 70-84, or visual deficit (<3/10 for one eye).

FINDINGS

In total, 1817 (77%) of the 2357 surviving children born very preterm had a medical assessment at 5 years and 396 (60%) of 664 in the reference group. Cerebral palsy was diagnosed in 159 (9%) of children born very preterm. Scores for MPC were available for 1534 children born very preterm: 503 (32%) had an MPC score less than 85 and 182 (12%) had an MPC score less than 70. Of the 320 children in the reference group, the corresponding values were 37 (12%) and 11 (3%), respectively. In the very preterm group, 83 (5%) had severe disability, 155 (9%) moderate disability, and 398 (25%) minor disability. Disability was highest in children born at 24-28 completed weeks of gestation (195 children [49%]), but the absolute number of children with disabilities was higher for children born at 29-32 weeks (441 children [36%]). Special health-care resources were used by 188 (42%) of children born at 24-28 weeks and 424 (31%) born at 29-32 weeks, compared with only 63 (16%) of those born at 39-40 weeks.

INTERPRETATION

In children who are born very preterm, cognitive and neuromotor impairments at 5 years of age increase with decreasing gestational age. Many of these children need a high level of specialised care. Prevention of the learning disabilities associated with cognitive deficiencies in this group is an important goal for modern perinatal care for children who are born very preterm and for their families.

Impact of the use of antenatal corticosteroids on mortality, cerebral lesions and 5-year neurodevelopmental outcomes of very preterm infants: the EPIPAGE cohort study

OBJECTIVE

To assess the impact of antenatal corticosteroids (ACS) on neonatal mortality, cerebral lesions and 5-year neurodevelopmental outcome of infants born at 24-27 and 28-32 weeks of gestational age (GA).

DESIGN

Observational population-based study including all births at GAs between 22 and 32 weeks in 1997 in nine regions of France. Survivors were assessed at the age of 5 years.

SAMPLE AND METHODS

The population enrolled in the follow up comprised 2323 infants; there were 23 deaths before age 5 years and outcome at 5 years was available for up to 1781 subjects. Two GA subgroups (24-27 and 28-32 weeks of GA) were analysed separately. Propensity scores were used to reduce bias in the estimation of the association between ACS treatment and outcomes.

MAIN OUTCOME MEASURES

Neonatal death, neonatal white matter injury, cerebral palsy, mental processing composite (MPC) of the Kaufman Assessment Battery for Children test and behavioural difficulties at 5 years.

RESULTS

In the 28- to 32-week GA subgroup, there was a significant association between ACS and a decreased risk of both neonatal death (OR = 0.61 [0.41-0.91]) and white matter injury (OR = 0.60 [0.46-0.79]) but only a nonsignificant trend for improved 5-year outcome (cerebral palsy, MPC < 70). In the 24- to 27-week GA subgroup, ACS was associated with a significant decrease risk of neonatal death (OR = 0.43 [0.27-0.68]) but there was only a trend for a lower risk of white matter injury and no beneficial impact on outcome at 5 years. Limiting the analysis to only those who received complete courses of ACS did not modify the results.

CONCLUSION

The study shows that ACS therapy greatly increases the survival of very preterm infants, including the most immature, but there is little evidence that ACS affects long-term neurodevelopmental and behavioural outcome in 28- to 32-week survivors, and none in <28-week survivors.

[Very preterm birth less than 33 weeks' gestation: how setting-up of a perinatal network does influence the activity of the neonatal tertiary care unit? The experience of the Poitou-Charentes region, France]

OBJECTIVES

To evaluate the impact of regional perinatal network setting on very preterm neonates (gestational age<33 weeks) referral and activity of regional level 3 NCIU, and short-term outcome of infants cared for.

POPULATION AND METHODS

Comparison of data from medical records of hospital days and hospital outcome of very preterm neonates born before and after the setting-up of regional perinatal network (2002-2005).

RESULTS

The setting-up of the Poitou-Charentes perinatal network has led to a 45% rise in number of very preterm neonates admitted to the level 3 neonatal care (114 in 2002, 166 in 2005), number of hospitalisation days has also increased by 31% in neonatology unit (2181 days in 2002, 2864 days in 2005) but remained stable in intensive care unit. A transient rise in neonatal mortality was observed, although the incidence of severe ultrasonographic cerebral abnormalities and that of bronchopulmonary dysplasia were lowered.

CONCLUSION

Setting-up of perinatal network in Poitou-Charentes (France) has led to improved access to level 3 neonatal care, with rise in very preterm neonates survival and low incidence of short-term sequelae.

Behavioral outcome at 3 years of age in very preterm infants: the EPIPAGE study

OBJECTIVES

Our goal was to compare the prevalence of behavioral problems between very preterm children and term children at 3 years of age and examine the factors associated with behavioral problems in very preterm children.

METHODS

We conducted a prospective population-based cohort study: the EPIPAGE (Etude Epidémiologique sur les Petits Ages Gestationnels) study. All infants born between 22 and 32 weeks of gestation in 9 regions of France in 1997 were included and compared with a control group of infants born at term. Sociodemographic status, obstetric, and neonatal data were collected at birth and in the neonatal units. At 3 years of age, the behavioral problems of 1228 very preterm singleton children without major neurodisabilities, and 447 term children were studied using the Strengths and Difficulties Questionnaire completed by the parents.

RESULTS

Very preterm children were more likely than controls to have behavioral difficulties. Among very preterm children, several medical conditions were associated with a high total difficulty score: major neonatal cerebral lesions diagnosed by cranial ultrasonographic studies, hospitalization within the last year, poor health, and psychomotor delay. A high birth order and sociodemographic factors such as young maternal age and low educational level of the mother were also identified as risk factors for behavioral difficulties. The differences between very preterm children and controls remained significant after adjustment for sociodemographic characteristics, neonatal complications, and neurodevelopmental status, for a high total difficulties score, hyperactivity, conduct problems, and for peer problems. For emotional problems, the difference was at the limit of significance.

CONCLUSIONS

Very preterm children have a higher risk of behavioral problems at 3 years of age compared with term-born children. Health and neurodevelopmental status of the child were significantly associated with behavioral difficulties.

Cerebral palsy among very preterm children in relation to gestational age and neonatal ultrasound abnormalities: the EPIPAGE cohort study

OBJECTIVE

To estimate the prevalence of cerebral palsy at 2 years of age among children born very preterm, according to gestational age, infant gender, plurality, and neonatal cranial ultrasound abnormalities.

METHODS

All infants born between 22 and 32 weeks of gestation in 9 regions of France in 1997 were included in this prospective, population-based, cohort study. The main outcome measure was cerebral palsy prevalence at 2 years. Of the 2364 survivors eligible for follow-up evaluation, 1954 (83%) were assessed at 2 years of age.

RESULTS

Among the 1954 children assessed at 2 years, 8.2% had cerebral palsy. Bilateral spastic cerebral palsy, hemiplegia, and monoplegia accounted for 72%, 9%, and 10% of cases, respectively. Fifty percent of the children with cerebral palsy walked independently at the age of 2, 31% were unable to walk but could sit independently, and 19% could not sit (unable to maintain head and trunk control). The prevalence of cerebral palsy was 20% at 24 to 26 weeks of gestation, compared with 4% at 32 weeks. On the basis of ultrasound findings in the neonatal period, we found that 17% of children with isolated grade III intraventricular hemorrhage and 25% of children with white matter damage (ie, ventricular dilation, persistent echodensities, or cystic periventricular leukomalacia) had cerebral palsy, compared with 4% of children with normal ultrasound scans.

CONCLUSIONS

Despite recent improvements in survival rates, cerebral palsy remains highly prevalent among very preterm children. Severe cranial ultrasound abnormalities predict motor disability strongly, but one third of infants with cerebral palsy had no ultrasound abnormalities.

Are maternal hypertension and small-for-gestational age risk factors for severe intraventricular hemorrhage and cystic periventricular leukomalacia? Results of the EPIPAGE cohort study

OBJECTIVE

The purpose of this study was to examine the relationships between different causes of preterm delivery (eg, maternal hypertension, small-for-gestational age [SGA], other) and cerebral damage (eg, cystic periventricular leukomalacia [c-PVL], grade III intraventricular hemorrhage [IVH], and intra-parenchymal hemorrhage [IPH]).

STUDY DESIGN

This study included 1902 very preterm singletons who were transferred to neonatal intensive care units in 9 French regions. We used logistic regression models to compare the risk of cerebral injury associated with maternal hypertension, SGA, and all other causes of preterm delivery.

RESULTS

We found that the risk of c-PVL and grade III IVH was higher in infants born after preterm premature rupture of membranes (PPROM) with short latency or idiopathic preterm labor than in infants born to hypertensive mothers. We show that SGA and antepartum maternal hemorrhage significantly increase the risk of IPH.

CONCLUSION

Our results show that infants born to hypertensive mothers have a lower risk of cerebral injuries than infants born following idiopathic preterm labor and PPROM because they are less exposed to prenatal infection.

[What diagnostic tools can be used to assess antenatal exposure to smoking? Pediatric experience]

In France, one out of four infants is born to a smoking mother. The short-, mid-, and long-term effects of antenatal exposure to smoking are only partially known. En Europe, it is generally accepted that most smoking mothers are aware of their smoking habit. Nevertheless, certain mothers deny their smoking or minimize the number of cigarettes smoked. The impact of anti-smoking campaigns on the frequency of maternal smoking and its recognition are unknown. The question is determine whether an objective marker of smoking in the neonatal period would be useful for individual care or epidemiological research. Cotinine and CO are the most widely used neonatalagy.

Smoking during pregnancy and preterm birth according to obstetric history: French national perinatal surveys

The relation between smoking and preterm delivery is not totally known. Our aim was to determine whether smoking during pregnancy was associated with preterm birth among women at different risk according to their obstetric history. The study was based on data from the 1998 French national perinatal survey. Of the 13073 singleton live births, 4.7% were preterm; 15% of the pregnant women were moderate (one to nine cigarettes per day) and 10% heavy smokers (at least 10 cigarettes per day). Smoking heavily was related to preterm birth (crude odds ratio [OR] = 1.35, 95% confidence interval [95% CI]: [1.04, 1.74]). Multivariable logistic regression showed a relation between smoking and preterm birth among multiparae without previous adverse pregnancy outcomes; the associated adjusted ORs (AORs) were 1.25 [95% CI 0.83, 1.87] among moderate smokers and 1.46 [95% CI 0.98, 2.20] among heavy smokers. The corresponding AORs were 0.69 [95% CI 0.46, 1.05]) and 0.96 [95% CI 0.59, 1.56] for primiparae and 1.11 [95% CI 0.63, 1.93] and 0.50 [95% CI 0.25, 0.98] for multiparae with previous adverse pregnancy outcomes. Our study showed a relation between heavy smoking during pregnancy and preterm birth mostly for women with low obstetric risk.

Smoking during pregnancy and preterm birth according to obstetric history: French national perinatal surveys

The relation between smoking and preterm delivery is not totally known. Our aim was to determine whether smoking during pregnancy was associated with preterm birth among women at different risk according to their obstetric history. The study was based on data from the 1998 French national perinatal survey. Of the 13073 singleton live births, 4.7% were preterm; 15% of the pregnant women were moderate (one to nine cigarettes per day) and 10% heavy smokers (at least 10 cigarettes per day). Smoking heavily was related to preterm birth (crude odds ratio [OR] = 1.35, 95% confidence interval [95% CI]: [1.04, 1.74]). Multivariable logistic regression showed a relation between smoking and preterm birth among multiparae without previous adverse pregnancy outcomes; the associated adjusted ORs (AORs) were 1.25 [95% CI 0.83, 1.87] among moderate smokers and 1.46 [95% CI 0.98, 2.20] among heavy smokers. The corresponding AORs were 0.69 [95% CI 0.46, 1.05]) and 0.96 [95% CI 0.59, 1.56] for primiparae and 1.11 [95% CI 0.63, 1.93] and 0.50 [95% CI 0.25, 0.98] for multiparae with previous adverse pregnancy outcomes. Our study showed a relation between heavy smoking during pregnancy and preterm birth mostly for women with low obstetric risk.

[Gestational diabetes and urinary tract malformations: a hospital case-control study]

INTRODUCTION

Urinary tract malformations represent the leading cause of renal failure in children. Gestational diabetes plays a controversial role in the development of urinary tract malformations. The purpose of this study was to assess the role of insulin-requiring gestational diabetes on the development of ureteric malformations in children.

MATERIAL AND METHODS

The authors report the results of a prospective case-control survey (102 cases, 104 controls) conducted in a teaching hospital. The role of insulin-requiring gestational diabetes on the development of urinary tract malformations was tested by logistic regression after adjustment for risk factors for urinary tract malformations 'family history of urinary tract malformations, parity, smoking, substance abuse during pregnancy).

RESULTS

Gestational diabetes is a risk factor for urinary tract malfornations after adjustment (aOR=5.1; 95%CI: 1.1-24.5), and for ureteropelvic junction syndrome (aOR=6.5; 95%CI: 1.1-39.4) and vesicoureteric reflux (aOR=5.9; 95%CI: 1.1-32.1).

CONCLUSION

All perinatal healthcare professionals must be familiar with the concept of insulin-requiring gestational diabetes as an uncommon, but fairly powerful risk factor for ureteric malformations.

Temperament at 9 months of very preterm infants born at less than 29 weeks' gestation: the Epipage study

The objective was to determine whether the temperament of very preterm singleton infants born before 29 weeks' gestation differs from their full-term counterparts at 9 months and to examine the influence of neurological sequelae on temperament in very preterm infants. The parents of very preterm infants from nine French regions and a group of full-term infants were sent the Infant Characteristics Questionnaire when the infants were 9 months old. The analysis included 266 singleton very preterm infants from the same regions born before 29 weeks' gestation and 546 full-term singleton infants. There were no significant differences for the Difficult, Unadaptable, and Unpredictable scales between very premature and term infants. Very preterm infants had a slightly higher Dull scale score than term infants. After taking into account mother's age, duration of hospitalization, and cerebral lesions found on neonatal ultrasound scans, this difference was no longer significant. Among very premature infants, those with cerebral lesions as diagnosed by neonatal ultrasound scan were rated higher on the Dull and Unadaptable scales. Delays in development at 9 months were also related to higher Dull and Unpredictable scales. These data suggest that prematurity does not affect temperament ratings at 9 months as assessed by the mother. However, very preterm infants with neurological insults, documented by the neonatal cerebral ultrasound or by a delay in development, are rated higher by their mothers on the Dull, Unadaptable, and Unpredictable scales.

Does smoking in pregnancy modify the impact of antenatal steroids on neonatal respiratory distress syndrome? Results of the Epipage study

OBJECTIVES

To assess the relation between cigarette smoking during pregnancy and neonatal respiratory distress syndrome (RDS) in very preterm birth, and to analyse the differential effect of antenatal steroids on RDS among smokers and non-smokers.

DESIGN

A population based cohort study (the French Epipage study).

SETTING

Regionally defined births in France.

METHODS

A total of 858 very preterm liveborn singletons (27-32 completed weeks of gestation) of the French Epipage study were included in this analysis. The odds ratio for RDS in relation to smoking in pregnancy was estimated using a logistic regression to control for gestational age. The odds ratio for RDS in relation to antenatal steroids was estimated taking into account an interaction between antenatal steroids and cigarette smoking, using multiple logistic regression to control for gestational age, birthweight ratio, main causes of preterm birth, mode of delivery, and sex.

RESULTS

The odds ratio for RDS in relation to smoking in pregnancy adjusted for gestational age (aOR) was 0.59 (95% confidence interval (CI) 0.44 to 0.79). The aOR for RDS in relation to antenatal steroids was 0.31 (95% CI 0.19 to 0.49) in babies born to non-smokers and 0.63 (95% CI 0.38 to 1.05) in those born to smokers; the difference was significant (p = 0.04).

CONCLUSIONS

Cigarette smoking during pregnancy is associated with a decrease in the risk of RDS in very preterm babies. Although antenatal steroids reduce the risk of RDS in babies born to both smokers and non-smokers, the reduction is smaller in those born to smokers.

Re-hospitalization in infants younger than 29 weeks' gestation in the EPIPAGE cohort

AIM

To estimate the re-hospitalization rate of extremely preterm children during infancy and associated factors after the recent improvement in survival rates.

METHOD

The cohort included all children born before 29 wk of gestation in nine French regions in 1997. All admissions between discharge from initial hospitalization and 9 mo after birth were considered. Factors studied included the child's characteristics at birth and during neonatal hospitalization, risk factors for infection after discharge and parents' socio-demographic characteristics. Adjusted odds ratios (aOR) for re-hospitalization for all reasons and for respiratory disorders were obtained from logistic regression models.

RESULTS

Of the 376 children, 178 were re-admitted at least once (47.3%; 95% CI: 42.3-52.4). Fifty-five percent of the hospitalized children were admitted at least once for respiratory disorders. The re-hospitalization rate was higher for children who had had chronic lung disease (aOR: 2.2; 95% CI: 1.3-3.7), those initially discharged between August and October (aOR: 2.5; 95% CI: 1.2-5.1) or between November and January (aOR: 3.2; 95% CI: 1.5-6.8), and children living with other children under six (aOR: 3.4; 95 %CI: 1.6-7.5). Re-hospitalizations were associated with neither gestational age nor the duration of neonatal hospitalization. Adjusted odds ratios for re-hospitalization for respiratory tract disorders were very similar to those for the overall hospitalizations.

CONCLUSION

Infants born before 29 wk have a very high risk of re-hospitalization. The associated factors can help define high-risk groups at discharge from the neonatal unit who need special surveillance.

The complex relationship between smoking in pregnancy and very preterm delivery. Results of the Epipage study

OBJECTIVE

To assess the relationship between cigarette smoking during pregnancy and very preterm births, according to the main mechanisms of preterm birth.

DESIGN

Case-control study (the French Epipage study).

SETTING

Regionally defined population of births in France.

POPULATION

Eight hundred and sixty-four very preterm live-born singletons (between 27 and 32 completed weeks of gestation) and 567 unmatched full-term controls.

METHODS

Data from the French Epipage study were analysed using a polytomous logistic regression model to control for social and demographic characteristics, pre-pregnancy body mass index and obstetric history. The main mechanisms of preterm delivery were classified as gestational hypertension, antepartum haemorrhage, premature rupture of membranes, spontaneous preterm labour and other miscellaneous mechanisms.

MAIN OUTCOME MEASURES

Odds ratios for very preterm birth for low to moderate (1-9 cigarettes/day) and heavy (>/=10 cigarettes/day) maternal smoking in pregnancy, estimated according to the main mechanisms leading to preterm birth.

RESULTS

Smokers were more likely to give birth to very preterm infants than non-smokers [adjusted odds ratio (aOR) 1.7, 95% confidence interval (CI) 1.3-2.2]. Heavy smoking significantly reduced the risk of very preterm birth due to gestational hypertension (aOR 0.5, 95% CI 0.3-1.0), whereas both low to moderate and heavy smoking increased the risk of very preterm birth due to all other mechanisms (aOR between 1.6 and 2.8).

CONCLUSION

These data from the Epipage study show that maternal smoking during pregnancy is a risk factor for very preterm birth. The impact of maternal smoking on very preterm birth appears to be complex: it lowers the risk of very preterm birth due to gestational hypertension, but increases the risk of very preterm birth due to other mechanisms. These findings might explain why maternal smoking is more closely related to preterm birth among multiparous women than among nulliparous women.

Survival of very preterm infants: Epipage, a population based cohort study

OBJECTIVE

To evaluate the outcome for all infants born before 33 weeks gestation until discharge from hospital.

DESIGN

A prospective observational population based study.

SETTING

Nine regions of France in 1997.

PATIENTS

All births or late terminations of pregnancy for fetal or maternal reasons between 22 and 32 weeks gestation.

MAIN OUTCOME MEASURE

Life status: stillbirth, live birth, death in delivery room, death in intensive care, decision to limit intensive care, survival to discharge.

RESULTS

A total of 722 late terminations, 772 stillbirths, and 2901 live births were recorded. The incidence of very preterm births was 1.3 per 100 live births and stillbirths. The survival rate for births between 22 and 32 weeks was 67% of all births (including stillbirths), 85% of live births, and 89% of infants admitted to neonatal intensive care units. Survival increased with gestational age: 31% of all infants born alive at 24 weeks survived to discharge, 78% at 28 weeks, and 97% at 32 weeks. Survival among live births was lower for small for gestational age infants, multiple births, and boys. Overall, 50% of deaths after birth followed decisions to withhold or withdraw intensive care: 66% of deaths in the delivery room, decreasing with increasing gestational age; 44% of deaths in the neonatal intensive care unit, with little variation with gestational age.

CONCLUSION

Among very preterm babies, chances of survival varies greatly according to the length of gestation. At all gestational ages, a large proportion of deaths are associated with a decision to limit intensive care.

White matter damage and intraventricular hemorrhage in very preterm infants: the EPIPAGE study

OBJECTIVE

To evaluate the prevalence of cranial ultrasound abnormalities in very preterm infants as a function of gestational age, plurality, intrauterine growth restriction, and death before discharge.

STUDY DESIGN

A prospective, population-based cohort of 2667 infants born between 22 and 32 weeks of gestation in 1997 in nine regions of France, transferred to a neonatal intensive care unit, for whom at least one cranial ultrasound scan was available.

RESULTS

The frequencies of white matter damage (WMD), major WMD, cystic periventricular leukomalacia (PVL), periventricular parenchymal hemorrhagic involvement, and intraventricular hemorrhage with ventricular dilatation were 21%, 8%, 5%, 3%, and 3%, respectively. The risk of WMD increased with decreasing gestational age. Mean age at diagnosis of cystic PVL was older for the most premature infants. Intraventricular hemorrhage with ventricular dilatation was associated with a higher risk of cystic PVL. Intrauterine growth restriction was not associated with a lower prevalence of cystic PVL.

CONCLUSION

The frequency of WMD is high in very preterm babies and is strongly related to gestational age. The incidence of cystic PVL did not differ between babies with intrauterine growth restriction and babies who were appropriate for gestational age.

[Smoking, fertility and very preterm birth]

In France, many couples in procreating age continue to smoke, despite recommendations to stop smoking before or during pregnancy. We reviewed the epidemiological associations between maternal or paternal smoking and both infertility and very preterm birth. It appears clearly that maternal smoking impairs natural and assisted fecundity. Furthermore, maternal smoking enhances the rate of ectopic pregnancies and spontaneous abortions. The role of maternal smoking on very preterm birth before 33 weeks of completed gestation appears in recent population based-study or case-control studies that include several hundred very preterm neonates. But the role of smoking on very preterm birth among hypertensive mothers and primiparae is still debated. The detrimental effect of smoking on fecundity appears to be reversible when the mother and father stop smoking. The real effect of interventions promoting cessation of smoking during pregnancy in reducing the rate of very preterm births remains to be studied.