Table 1.

Demographic data of participating women delivering at < 37 weeks of gestation (cases) or at term (controls) (mean ± SD).

	Cases (n = 13)	Controls (n = 21)	P value
Age (y)	38.0 (±1.1)	37.1 (±0.7)	.50
Gestational weeks at
amniocentesis	18.5 (±0.6)	17.4 (±0.3)	.07
Body mass index	25.5 (±1.8)	22.5 (±0.9)	.12
Gender of offspring	—	—	.63
Male	7 (53.8%)	13 (61.9%)	—
Female	6 (46.2%)	8 (38.1%)	—