Table 2 Difference between the LMP and 7–20-week ultrasound-based estimates of gestational age at birth according to maternal characteristics and differences between the Capurro method and 7–20-week ultrasound-based estimates according to infant characteristics
GA difference (in days): LMP - US estimate | ||||||||
|---|---|---|---|---|---|---|---|---|
n | Mean of difference (SD) | < −14 | (−14 to −8) | ±7 | (+8 to+14) | > +14 | P- value | |
Total | 1082 | −0.01 (2.4) | 9.1 | 7.0 | 65.1 | 8.1 | 10.6 | - |
City | ||||||||
Petrópolis | 630 | −0.01 (2.4) | 8.6 | 7.0 | 65.9 | 7.9 | 10.6 | 0.941 |
Queimados | 452 | −0.01 (2.3) | 10.0 | 7.1 | 63.9 | 8.4 | 10.6 | |
Age | ||||||||
10 - 19 years | 238 | 0.08 (2.6) | 10.5 | 5.9 | 59.2 | 10.9 | 13.4 | 0.007 |
20 - 34 years | 751 | 0.06 (2.3) | 8.0 | 6.5 | 67.8 | 7.6 | 10.1 | |
≥ 35 | 93 | −0.76 (2.5) | 15.1 | 14.0 | 58.1 | 5.4 | 7.5 | |
Ethnicity | ||||||||
White | 391 | 0.05 (2.4) | 8.7 | 6.1 | 65.2 | 8.7 | 11.3 | 0.989 |
Mixed race | 452 | −0.02 (2.4) | 9.3 | 7.7 | 64.8 | 7.5 | 10.6 | |
Black | 239 | −0.08 (2.2) | 9.6 | 7.1 | 65.3 | 8.4 | 9.6 | |
Years of schooling | ||||||||
≤ 4 | 135 | −0.31 (2.6) | 14.1 | 11.9 | 58.5 | 7.4 | 8.1 | 0.120 |
5 to 8 | 475 | 0.03 (2.5) | 8.6 | 6.7 | 64.4 | 8.2 | 12.0 | |
≥ 9 | 472 | 0.04 (2.2) | 8.3 | 5.9 | 67.6 | 8.3 | 10.0 | |
Marital Status | ||||||||
Married | 813 | 0.03 (2.4) | 8.9 | 7.5 | 64.6 | 7.0 | 12.1 | 0.012 |
Not married | 269 | −0.12 (2.2) | 13.7 | 5.6 | 66.5 | 11.5 | 6.3 | |
Parity | ||||||||
First child | 487 | 0.01 (2.3) | 7.6 | 7.2 | 67.1 | 7.4 | 10.7 | 0.388 |
Second or third child | 459 | 0.09 (2.3) | 9.7 | 6.0 | 65.1 | 8.6 | 10.7 | |
Forth or more | 133 | −0.39 (2.9) | 12.8 | 10.5 | 57.1 | 9.0 | 10.5 | |
Certainty of LMP date | ||||||||
Sure | 847 | 0.01 (2.2) | 7.7 | 6.0 | 68.7 | 8.3 | 9.3 | <0.001 |
Not sure | 234 | −0.08 (3.0) | 14.1 | 10.7 | 52.1 | 7.7 | 15.4 | |
GA difference (in days): Capurro- US estimate | ||||||||
n | Mean of difference (SD) | < −14 | (−14 to −8) | ±7 | (+8 to+ 14) | > +14 | P-value | |
Infant birth weight | ||||||||
< 2500 | 81 | 0.20 (2.0) | 3.7 | 12.3 | 58.0 | 12.3 | 13.6 | <0.001 |
2500-3499 | 630 | −0.37 (1.8) | 12.9 | 15.4 | 58.7 | 7.1 | 5.9 | |
3500- 3999 | 199 | −0.37 (1.4) | 7.5 | 13.6 | 71.9 | 5.0 | 2.0 | |
> 4000 | 49 | 0.38 (1.6) | 2.0 | 14.3 | 57.1 | 16.3 | 10.2 | |
Gestational age at birth | ||||||||
<=36 | 114 | 1.19 (1.9) | 0.9 | 4.4 | 57.0 | 14.0 | 23.7 | <0.001 |
37 | 108 | 0.81 (1.4) | 0.0 | 3.7 | 60.2 | 20.4 | 15.7 | |
38-39 | 420 | −0.25 (1.4) | 6.9 | 16.0 | 66.7 | 7.4 | 3.1 | |
40-41 | 304 | −1.11 ( 1.3) | 20.4 | 20.1 | 58.2 | 1.3 | 0.0 | |
>=42 | 14 | −3.93 (3.3) | 64.3 | 28.6 | 7.1 | 0.0 | 0.0 | |