Asperger syndrome (AS) is a pervasive developmental disorder widely regarded as a mild variant of autism. To investigate if AS is associated with a history of fewer obstetric insults compared to autism, we examined the developmental history and obstetric records of 10 males with AS (mean full scale IQ 95.3), and compared them with 10 autistic males with a full scale IQ of 70 or above (so-called high-functioning autism; mean full scale IQ 82.6). Males with AS showed a trend toward lower Apgar scores at one minute (chi-square = 4; df = 1; P = 0.04) and were more likely to have been born to mothers outside the optimal age group of 20-30 years (chi-square = 5; df = 1; P = 0.02). They were also less likely to have been irritable and floppy as infants (chi-square = 3.8; df = 1; P = 0.05). However, the total optimality scores did not differ significantly between the two groups.