Table 2.
Perinatal characteristics according to the quality of gestational age information at birth.
| Characteristics | PDa with USb<14 weeks (N=1163) | PD with US<20 weeks (N=1456) | Suboptimal PDc (N=657) | P valued | P valuee |
| Maternal-fetal diseases, n (%) | 684 (58.81) | 843 (57.89) | 374 (56.93) | .43f | .68f |
| Hypertensive disorders, n (%) | 202 (17.38) | 243 (16.69) | 102 (15.53) | .31f | .50f |
| Diabetes, n (%) | 116 (9.97) | 134 (9.2) | 45 (6.85) | .02f | .07f |
| Maternal blood transfusion after birth, n (%) | 17 (1.46) | 25 (1.72) | 20 (3.04) | .02f | .048f |
| ICUg maternal admission, n (%) | 12 (1.03) | 14 (0.96) | 10 (1.52) | .35f | .26f |
| 5-minute Apgar score, median (IQR) | 9 (1) | 9 (1) | 9 (1) | .64h | .47h |
| Live birth weight (g), median (IQR) | 3025 (735) | 303 (735) | 3030 (755) | .79h | .70h |
| Major malformations, n (%) | 136 (11.69) | 162 (11.13) | 66 (10.05) | .28f | .46f |
| Neonatal resuscitationi, n (%) | 133 (11.44) | 162 (11.13) | 62 (9.44) | .19f | .24f |
| Neonatal resuscitationi,j, n (%) | 100 (9.74) | 125 (9.66) | 51 (8.63) | .46f | .48f |
| NICUk admission, n (%) | 204 (18.13) | 251 (17.85) | 131 (20.99) | .15f | .095f |
| NICU admissionj, n (%) | 133 (13.25) | 168 (13.30) | 103 (18.07) | .01f | .008f |
| Fetal or neonatal mortality, n (%) | 70 (6.02) | 89 (6.11) | 47 (7.15) | .34f | .37f |
| Fetal or newborn mortalityj, n (%) | 32 (3.12) | 43 (3.32) | 28 (4.74) | .10f | .13f |
aPD: pregnancy dating.
bUS: ultrasound.
cUltrasound done ≥20 weeks of gestation or not done at all.
dComparison between ultrasound dating <14 weeks and suboptimal dating.
eComparison between ultrasound dating <20 weeks and suboptimal dating.
fChi-square test used.
gICU: intensive care unit.
hMann-Whitney test used.
iAt least one step of neonatal resuscitation [14].
jExcluding major malformations.
kNICU: neonatal intensive care unit.