TABLE 1

Perinatal Factors Potentially Associated With Weight Status at ≥24 Months of Age or With Antibiotic Exposure in Infancy

FactorUnderweight or Normal WeightOverweight or ObesePUnexposedExposedP
Boys
n4738137612864828
 Maternal age, yNSNS
  <301922 (40.6)555 (40.3)539 (41.9)1939 (40.1)
  ≥302816 (59.4)821 (59.7)747 (58.1)2889 (59.9)
 Maternal smoking after first trimestera<0.01NS
  No4319 (91.2)1221 (88.7)1163 (90.4)4378 (90.7)
  Yes289 (6.1)113 (8.2)77 (6.0)324 (6.7)
 Maternal relationshipa0.001<0.05
  Partner4358 (92.0)1238 (90.0)1154 (89.7)4451 (92.2)
  Single263 (5.6)109 (7.9)93 (7.2)270 (6.0)
 Gestational age, wksNSNS
  <402290 (48.3)642 (46.7)623 (48.4)2310 (47.9)
  ≥402448 (51.7)734 (53.3)663 (51.6)2518 (52.1)
 Mode of delivery<0.05NS
  Vaginal3971 (83.8)1118 (81.3)1078 (83.8)4013 (83.1)
  Cesarean767 (16.2)258 (18.8)208 (16.2)815 (16.9)
 ParityNS<0.001
  0 sibling2282 (48.2)640 (46.5)709 (55.1)2213 (45.8)
  ≥1 siblings2256 (51.8)736 (53.5)577 (44.9)2615 (54.2)
 PluralityNSNS
  Singleton4638 (97.9)1351 (98.2)1259 (98.0)4730 (98.0)
  Twin100 (2.1)25 (1.8)27 (2.0)98 (2.0)
 Season at birthNSNS
  Spring or summer2035 (43.0)556 (40.4)553 (43.0)2037 (42.2)
  Autumn or winter2703 (57.0)820 (59.6)733 (57.0)2791 (57.8)
 Birth size, weightb<0.001NS
  AGA4541 (95.8)1310 (95.2)1224 (95.2)4628 (95.9)
  SGA129 (2.7)15 (1.1)36 (2.8)105 (2.2)
  LGA68 (1.4)51 (3.7)26 (2.0)95 (1.9)
 Birth size, lengthb<0.001NS
  AGA4532 (95.7)1288 (93.6)1230 (95.6)4589 (95.1)
  SGA101 (2.1)21 (1.5)28 (2.2)95 (1.9)
  LGA105 (2.2)67 (4.9)28 (2.2)144 (3.0)
 Exposure to antibiotics at <24 mo<0.05
  No1031 (21.8)255 (18.2)1286 (100)0
  Yes3707 (78.2)1121 (81.5)04828 (100)
Girls
n523071815404408
 Maternal age, yearsNS<0.05
  <30 y2182 (41.7)291 (40.5)664 (43.2)1810 (41.1)
  ≥30 y3048 (58.3)427 (59.5)876 (56.8)2598 (58.9)
 Maternal smoking after first trimesterc<0.001NS
  No4770 (91.2)630 (87.7)1399 (90.8)4001 (90.8)
  Yes324 (6.2)71 (9.9)88 (5.7)307 (7.0)
 Maternal relationshipcNSNS
  Partner4767 (91.1)646 (90.0)1382 (89.7)4039 (91.6)
  Single336 (6.4)52 (7.2)107 (6.9)273 (6.2)
 Gestational age, weeksNSNS
  <402344 (44.8)321 (44.7)696 (45.2)1969 (44.7)
  ≥402886 (55.2)397 (55.3)844 (54.8)2439 (55.3)
 Mode of delivery<0.05NS
  Vaginal4414 (84.4)584 (81.3)1299 (84.4)3702 (84.0)
  Cesarean section816 (15.6)134 (18.7)241 (15.6)706 (16.0)
 ParityNS<0.001
  0 sibling2487 (47.6)340 (47.4)825 (53.6)2001 (45.4)
  ≥1 siblings2743 (52.4)378 (52.6)715 (46.4)2407 (54.6)
 PluralityNSNS
  Singleton5127 (98.0)709 (98.7)1514 98.4)4323 (98.1)
  Twin103 (2.0)9 (1.3)26 (1.6)85 (1.9)
 Season at birthNSNS
  Spring or summer2212 (42.3)312 (43.5)660 (42.8)1864 (42.3)
  Autumn or winter3018 (57.7)406 (56.5)880 (57.2)2544 (57.7)
 Birth size / wtb<0.001<0.05
  AGA4999 (95.6)678 (94.4)1480 (96.2)4196 (95.2)
  SGA103 (2.0)6 (0.8)29 (1.9)79 (1.8)
  LGA128 (2.4)34 (4.7)31 (2.0)133 (3.0)
 Birth size / lengthbNSNS
  AGA4976 (95.1)685 (95.4)1465 (95.2)4195 (95.2)
  SGA100 (1.9)7 (1.0)29 (1.8)80 (1.8)
  LGA154 (3.0)26 (3.6)46 (3.0)133 (3.0)
 Exposure to antibiotics < 24 moNS
  No1374 (26.3)166 (23.1)1540 (100)0
  Yes3856 (73.3)552 (76.9)04408 (100)
  • Values are expressed as n (%). AGA, appropriate for gestational age; LGA, large for gestational age; NS, statistically nonsignificant; SGA, small for gestational age. —, indicates P value is not available.

  • a Not available: maternal smoking n = 172; maternal relationship n = 146.

  • b Finnish growth reference for birth size.20

  • c Not available: maternal smoking n = 153; maternal relationship n = 147.