Maternal smoking during pregnancy and regional brain volumes in preterm infants.

OBJECTIVE: To evaluate the association between maternal smoking during pregnancy and both brain volumes and head circumference in very-low-birth-weight/very-low-gestational-age infants. STUDY DESIGN: The PIPARI Study is a prospective follow-up study of infants with a birth weight < or =1500 g or a gestational age <32 weeks born in 2001 to 2006 (n = 232) at Turku University Hospital. The brain was imaged by serial brain ultrasound examinations until discharge and magnetic resonance imaging at term age. The head circumference was measured at birth, term, and 2 years corrected age. These measures were correlated to maternal smoking during pregnancy as reported by the mothers. RESULTS: The prevalence of maternal smoking was 18%. The frontal lobe (P = .01) and the cerebellar (P = .03) volumes were significantly smaller in the exposed than in the unexposed infants. The volumes of the other parts of the brain did not differ. There was no association between prenatal smoking exposure and head growth or structural brain disease. CONCLUSIONS: Prenatal smoking exposure was associated with significantly smaller frontal lobe and cerebellar volumes in the brains of preterm infants. This is consistent with reports showing an association between prenatal smoking exposure and impairments in frontal lobe and cerebellar functions such as emotion, impulse control, and attention.

Does placental inflammation relate to brain lesions and volume in preterm infants?

OBJECTIVES: To evaluate the association between histologic inflammation of placenta and brain findings in ultrasound examinations and regional brain volumes in magnetic resonance imaging in very-low-birth-weight (VLBW) or in very preterm infants. STUDY DESIGN: VLBW or very preterm infants (n = 121) were categorized into 3 groups according to the most pathologic brain finding on ultrasound examinations until term. The brain magnetic resonance imaging performed at term was analyzed for regional brain volumes. The placentas were analyzed for histologic inflammatory findings. RESULTS: Histologic chorioamnionitis on the fetal side correlated to brain lesions in univariate but not in multivariate analyses. Low gestational age was the only significant risk factor for brain lesions in multivariate analysis (P < .0001). Histologic chorioamnionitis was not associated with brain volumes in multivariate analyses. Female sex, low gestational age, and low birth weight z score correlated to smaller volumes in total brain tissue (P = .001, P = .0002, P < .0001, respectively) and cerebellum (P = .047, P = .003, P = .001, respectively). In addition, low gestational age and low-birth-weight z score correlated to a smaller combined volume of basal ganglia and thalami (P = .0002). CONCLUSIONS: Placental inflammation does not appear to correlate to brain lesions or smaller regional brain volumes in VLBW or in very preterm infants at term age.

Antenatal Doppler measurements and early brain injury in very low birth weight infants.

OBJECTIVE: To determine the correlation between fetoplacental blood flow and brain injury and volumes in very low birth weight (VLBW) infants. STUDY DESIGN: Antenatal blood flow from the umbilical artery (UA), middle cerebral artery (MCA), and descending aorta was determined in 70 VLBW infants. The directions of the total diastolic flow of the aortic isthmus and the end-diastolic flow of ductus venosus also were measured. Serial brain ultrasound examinations and MRI at term were performed to assess brain abnormalities. On the basis of brain imaging findings, the newborn infants were classified as normal (n = 14), intermediate brain pathology (n = 31), and major pathology (n = 25) groups. RESULTS: Abnormalities in fetoplacental blood flow were not related to anatomic brain lesions. However, an abnormal UA/MCA pulsatility index ratio was associated with reduced total brain volume (mean, 360 mL; SD, 32.5 mL) and reduced cerebral volume (344 mL; SD, 28.4 mL) compared with infants with normal UA/MCA pulsatility index ratio (mean, 405 mL; SD, 51.3 mL, P = .01, and mean, 368 mL; SD, 52.3 mL, P = .012), respectively. CONCLUSIONS: Redistribution of fetal blood flow in VLBW infants is associated with reduced brain volume at term age. Neurodevelopmental follow-up of this cohort will clarify the significance of these blood flow changes on development.