Skip to main content

Table 1 Maternal characteristics according to NVP status

From: Nausea and vomiting during pregnancy associated with lower incidence of preterm births: the Japan Environment and Children’s Study (JECS)

  Total No NVP Mild NVP Moderate NVP Severe NVP P value
n = 96,056 n = 16,596 n = 41,198 n = 27,744 n = 10,518
n n (%) n (%) n (%) n (%)
Maternal Age (years)
  < 20 814 190 (1.2) 256 (0.6) 256 (0.9) 112 (1.1) <  0.001
 20–24 8630 1678 (10.1) 3026 (7.4) 2787 (10.1) 1139 (10.8)  
 25–29 26,528 4487 (27.0) 10,775 (26.2) 8111 (29.2) 3155 (30.0)  
 30–34 34,075 5432 (32.7) 14,997 (36.4) 9967 (35.9) 3679 (35.0)  
 35–39 21,622 3861 (23.3) 10,038 (24.4) 5636 (20.3) 2087 (19.8)  
  ≥ 40 4383 945 (5.7) 2106 (5.1) 986 (3.6) 346 (3.3)  
 Missinga 4      
Parity
 Nullipara 37,800 8244 (51.4) 15,404 (38.2) 10,040 (36.9) 4112 (40.1) <  0.001
 Multipara 56,005 7804 (48.6) 24,875 (61.8) 17,170 (63.1) 6156 (60.0)  
 Missinga 2251      
Education (years)
  ≤ 12 34,790 6398 (38.7) 14,118 (34.4) 10,320 (37.3) 3954 (37.8) <  0.001
  > 12 60,893 10,126 (61.3) 26,931 (65.6) 17,315 (62.7) 6521 (62.3)  
 Missinga 373      
BMI (kg/m2)
  < 18.5 15,500 2859 (17.2) 6834 (16.6) 4167 (15.0) 1640 (15.6) <  0.001
 18.5–24.9 70,221 12,141 (73.2) 30,216 (73.4) 20,351 (73.4) 7513 (71.5)  
  ≥ 25 10,272 1584 (9.6) 4122 (10.0) 3209 (11.6) 1357 (12.9)  
 Missinga 63      
Smoking during pregnancy
 No 90,887 15,325 (93.3) 39,155 (95.8) 26,294 (95.5) 10,113 (97.0) <  0.001
 Yes 4386 1106 (6.7) 1724 (4.2) 1239 (4.5) 317 (3.0)  
 Missinga 783      
Pregnancy Complications
 Threatened abortion 11,428 1695 (10.2) 4885 (11.9) 3451 (12.4) 1397 (13.3) <  0.001
 Threatened premature labor 18,715 2896 (17.5) 7990 (19.4) 5566 (20.1) 2263 (21.5) <  0.001
 Premature rupture of membrane 7932 1549 (9.3) 3374 (8.2) 2218 (8.0) 791 (7.5) <  0.001
 Pregnancy-induced hypertension 2964 622 (3.8) 1189 (2.9) 841 (3.0) 312 (3.0) <  0.001
  1. Chi-squared test
  2. a Not included in percentage distribution