Table 3. Characteristics of participants in the P4 study (n=80).

Covariate	Frequency	N (%)
Maternal age category (years)
<25	6	7.50
25–29	11	13.75
30–34	37	46.25
35–39	19	23.75
40+	7	8.75
Parity category
1	37	46.25
2	34	42.50
≥3	9	11.25
Pre-pregnancy BMI
Underweight/normal	53	71.62
Overweight	15	20.27
Obese	6	8.11
Income
≤70,000	11	13.75
70,001–80,000	7	8.75
80,001–100,000	13	16.25
More than 100,000	44	55
Foreign born
Yes	17	21.25
No	63	78.75
Smoking history
Never	53	67.95
Ever	25	32.05
Season of conception
Fall	23	28.75
Winter	17	21.25
Spring	21	26.25
Summer	19	23.75