Maternal smoking during pregnancy and fetal growth. Effects in preterm infants of gestational age less than 33 weeks.

OBJECTIVE: To evaluate the effects of maternal smoking during pregnancy on foetal growth in preterm infants with gestational age (GA) <33 weeks. POPULATION AND METHODS: Prospective observational cross-sectional study from two French perinatal networks cohort of preterm infants. Cases were 358 very preterm infants (GA 24-32 weeks) divided into two groups as maternal smokers (129) and non-smokers (229). 361 term infants (GA 37-41 weeks) also divided into two groups as maternal smokers (129) and non-smokers (232) served as comparison group (controls). We studied the influence of maternal smoking on foetal anthropometric growth parameters (BW, BL and head circumference defined according to AUDIPOG curves) in groups and compared cases and controls. Other causes of foetal growth restriction were excluded. RESULTS: Maternal characteristics (age, height, pre-pregnancy body weight, parity, foetus sex) were similar in both groups and sub-groups. Mothers who smoked were younger (P <0.001), more likely to be unemployed (P <0.001) and to have undergone less school education (P <0.001). Smoking did not alter foetal growth in preterm infants: maternal smokers versus non-smokers BW (P = 0.52), BL (P = 0.44) and HC (P = 0.81). Growth restriction was marked in term infants with BW (P <0.001), BL (P <0.001) and HC (P <0.01). In multivariate analysis, after adjustment for other confounding factors, foetal growth appeared to be significantly altered by maternal smoking during pregnancy only in term infants. CONCLUSION: Our study suggests that effects of maternal smoking during pregnancy on foetal growth are gestational age-dependent.

Term neonate prognoses after perinatal asphyxia: contributions of MR imaging, MR spectroscopy, relaxation times, and apparent diffusion coefficients.

PURPOSE: To retrospectively evaluate magnetic resonance (MR) imaging, hydrogen 1 (1H) MR spectroscopy, apparent diffusion coefficient (ADC), T1, and T2 measurements for prediction of late neurologic outcome in term neonates after severe perinatal asphyxia. MATERIALS AND METHODS: This study was approved by the local ethics committee. Informed consent from parents was not required. Thirty term neonates (12 boys, 18 girls; age range, 2-12 days) with severe hypoxic-ischemic encephalopathy were examined during the first 12 days of life with conventional and diffusion-weighted cerebral MR imaging, 1H MR spectroscopy with absolute quantification, and T1 and T2 measurements. Quantitative 1H MR spectroscopy, T1, and T2 data were acquired on one 10-mm slab positioned at the level of the basal ganglia. The neonates were assigned to one of two groups according to their late (>12-month follow-up) neurologic outcome: those with an unfavorable outcome-that is, death or severe disability-and those with a favorable outcome. Clinical data, MR signal intensity abnormalities, ADCs, 1H MR spectroscopy findings, and relaxation times were compared by using Chi2 testing and analysis of variance to individualize the prognostic indicators. RESULTS: The unfavorable (n=16) and favorable (n=14) outcome groups were similar in terms of clinical data (ie, Apgar scores, visceral hypoxic injuries), visualization of brain edema on MR images, and T1 and T2 relaxation times. Late unfavorable neurologic outcome was associated with a mixed pattern of cortical and basal ganglia signal intensity abnormalities on MR images (13 babies with unfavorable vs three babies with favorable outcomes, P=.001) and with decreased absolute N-acetylaspartate (NAA) and choline concentrations in all brain structures, especially the basal ganglia (mean NAA concentration: 2.72 mmol/L in unfavorable outcome group vs 4.66 mmol/L in favorable outcome group, P<5x10(-9)), as measured with MR spectroscopy. In the basal ganglia, an NAA concentration lower than 4 mmol/L indicated an unfavorable individual prognosis with 94% sensitivity and 93% specificity. Significantly reduced ADCs also were noted in the unfavorable outcome group, but only during the first 6 days of life. CONCLUSION: Conventional MR imaging findings, spectroscopically measured absolute NAA and choline concentrations, and ADCs are complementary tools for predicting the individual outcomes of severely asphyxiated term neonates.