Table 1.

Maternal demographic and birth characteristics of 1,011 mothers in Puerto Rico from 2011 to 2019.

	Median (IQR)
Gestationals age at delivery (wk)	39.3 (1.79)
Birth weight z-score	0.09 (1.31)

	n (%)
Preterm Birth
Yes	89 (8.9%)
No	911 (90.1%)
Missing	11
Spontaneous preterm birth
Yes	52 (7.1%)
No	921 (92.9%)
Missing	38
Small for gestational age
Yes	89 (9.2%)
No	876 (90.8%)
Missing	46
Large for gestational age
Yes	106 (11%)
No	859 (89%)
Missing	46
Maternal age (y)
18–24	357 (35.3%)
25–29	309 (30.6%)
30–34	214 (21.2%)
35–41	131 (13.0%)
Missing	0
Maternal education
GED or less	195 (19.3%)
Some college	337 (33.3%)
Bachelor’s or higher	479 (47.4%)
Missing	0
Employment status
No	344 (34.2%)
Yes	662 (65.8%)
Missing	5
Annual household income (USD$)
$<\mathrm{10,000}$	255 (28.4%)
$\mathrm{10,000}\le \mathrm{30,000}$	293 (32.7%)
$\mathrm{30,000}\le \mathrm{50,000}$	223 (24.9%)
$\ge \mathrm{50,000}$	126 (14%)
Missing	114
Marital status
Single	168 (16.7%)
Married	553 (54.9%)
Cohabitating	286 (28.4%)
Missing	4
Smoking status
Never	873 (86.6%)
Ever	118 (11.7%)
Current	17 (1.7%)
Missing	3
Daily environmental tobacco smoke exposure
Never	848 (91.5%)
1 h or less	37 (4%)
$>1\mathrm{h}$	42 (4.5%)
Missing	84
Alcohol use
Never	520 (51.6%)
Yes, before Pregnancy	429 (42.6%)
Yes, currently	58 (5.8%)
Missing	4
Number of previous children
0	327 (39.9%)
1	375 (45.8%)
2–5	117 (14.3%)
Missing	192
Prepregnancy BMI
$\text{BMI}\le 25$	515 (53.5%)
$25<\text{BMI}\le 30$	269 (28%)
$\text{BMI}>30$	178 (18.5%)
Missing	49
Fetal sex
Female	462 (46%)
Male	540 (54%)
Missing	9

Note: BMI, body mass index; IQR, interquartile range.