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. Author manuscript; available in PMC: 2024 Jul 1.
Published in final edited form as: Epidemiology. 2023 May 30;34(4):576–588. doi: 10.1097/EDE.0000000000001621

Table 1.

Maternal and infant characteristics for mothers of participants with gastroschisis (cases) and infants without a birth defect (controls), National Birth Defects Prevention Study, 1997–2011

Gastroschisis Cases n = 1,269 Controls n = 10,217 Total n = 11,486

Maternal age at conception (years), n(%)
 <20 540 (43) 1294 (13) 1834 (16)
 20–25 541 (43) 2969 (29) 3510 (31)
 26–35 178 (14) 5106 (50) 5284 (46)
 ≥36 10 (1) 848 (8) 858 (7)

Parity, n(%)
 0 830 (65) 3986 (39) 4816 (42)
 1 272 (21) 3334 (33) 3606 (31)
 ≥2 166 (13) 2891 (28) 3057 (27)
 Missing 1 (0) 6 (0) 7 (0)

Maternal race/ethnicity, n(%)
 Non-Hispanic White 644 (51) 5981 (59) 6625 (58)
 Non-Hispanic Black 107 (8) 1089 (11) 1196 (10)
 Hispanic 410 (32) 2486 (24) 2896 (25)
 Other 108 (9) 661 (6) 769 (7)

Maternal pre-pregnancy BMI (kg/m2), n(%)
 Underweight (<18.5) 109 (9) 508 (5.0) 617 (5)
 Normal weight (18.5≤BMI<25) 830 (65) 5198 (50.9) 6028 (53)
 Overweight (25≤BMI<30) 223 (18) 2251 (22.0) 2474 (22)
 Obese (≥30) 71 (6) 1858 (18.2) 1929 (17)
 Missing 36 (3) 402 (3.9) 438 (4)

Maternal education (years), n(%)
 <12 348 (27) 1692 (17) 2040 (18)
 12 488 (38) 2437 (24) 2925 (25.5)
 >12 434 (34) 6087 (60) 6521 (57)

Annual household income ($USD), n(%)
 <$10,000 438 (35) 2018 (20) 2456 (21.4)
 $10,000 – $50,000 684 (54) 4666 (46) 5350 (46.6)
 >$50,000 147 (12) 3533 (35) 3680 (32.0)

Maternal employment, n(%)
 Employed 852 (67) 7213 (71) 8065 (70)
 Unemployed 376 (30) 2839 (28) 3215 (28)
 Unknown 0 (0) 5 (0) 5 (0)
 Missing 41 (3) 160 (2) 201 (2)

Maternal recreational drug usea,b, n(%)
 Yes 171 (14) 456 (5) 627 (5)
 No 1057 (83) 9600 (94) 10657 (93)
 Missing 41 (3) 161 (2) 202 (2)

Maternal smokinga, n(%)
 Yes 438 (35) 1812 (18) 2250 (2)
 No 793 (63) 8250 (81) 9043 (79)
 Missing 38 (3) 155 (2) 193 (2)

Maternal alcohola, n(%)
 Yes 518 (41) 3752 (37) 4270 (37)
 No 708 (56) 6284 (62) 6992 (61)
 Missing 43 (3) 181 (2) 224 (2)

Gestational age at delivery (weeks), n(%)
 Very preterm (<32 wks) 80 (6) 107 (1) 187 (2)
 Preterm (32–36 wks) 710 (56) 725 (7) 1435 (12
 Term (37–45 wks) 478 (38) 9384 (92) 9862 (86)
 Missing 1 (0) 1 (0) 2 (0)

Duration of residence (days), mean (range) 952 (30 – 14,152) 1,274 (30 – 14,456) 1,239 (30 – 14,456)

BMI: Body mass index

a

Self-reported use between one month prior to conception to third month of pregnancy

b

Recreational drug use includes: marijuana, hash, cocaine, crack, hallucinogens, heroin, hallucinogenic mushrooms