Association of preterm birth with brain malformations

Abstract

This study investigates the rate of preterm birth in babies with congenital brain defects. Autopsy case reports of congenital brain anomalies were obtained from the literature. The control cases were from a large registry, a published report from the Metropolitan Atlanta Congenital Defects Program. From 428 publications, 1168 cases were abstracted that had autopsy studies of congenital brain defects and information on the gestational age (GA) at birth. The control data from Atlanta included 7738 infants with significant birth defects of any kind and 264,392 infants without birth defects. In the autopsy cases with brain defects, the mean GA was 36.6 wk, whereas the Atlanta data showed a mean GA of 39.3 wk for infants with no defects and a significantly shorter gestation of 38.1 wk (p < 0.0001) for infants with defects. In the Atlanta data, the rate of preterm birth was 9.3% for those with no defects compared with 21.5% (p < 0.0001) for those with defects. In the autopsy cases with brain defects, the rate of preterm birth was even greater (33.1%, p < 0.0001). In conclusion, these data show an association of brain defects with preterm births.

Figure 1

Percent of subjects with and without birth defects by gestational age. The solid line is for brain defects from the autopsy reports; the dashed line is for birth defects from the MACDP registry; and the dotted line is for infants without defects, from the MACDP registry.

Figure 2

The relative risk for birth at weekly gestational ages. The straight dotted line at 1.0 represents the reference data line for infants without defects (from the MACDP registry). To eliminate distortions that might arise from the saw-tooth pattern of peaks on even-numbered weeks, the data were calculated in bins of two weeks at one-week intervals. The solid line is for brain defects from the autopsy reports, and the dashed line is for birth defects from the MACDP registry.