Maternal characteristics:
Age (years) 32 (24-37) 31 (20-40) NS, p=0.75
BMI (kg/m2) 23.5 (22-30) 24.5 (19-43) NS, p=0.87
Parity 1.5 (1-3) 1 (0-2) p<0.05
Nulliparity (%) 3 (50) 43 (89.6) p<0.05
Gestational age at sampling (weeks) 34.6 (31.7-39.1) 32.8 (20.4-39.3) NS, p=0.24