Introduction
Methods
Study design overview
Sample size calculation
Maternal characteristics
Neonatal characteristics
Ultrasonic data collection
Transformed ultrasound data according to GA
Estimated fetal weight (EFW)
AC growth velocity
A SGA predictor (SGAp) model
Statistical analysis
Results
Patient characteristics
Characteristics | SGA | AGA | LGA | P |
---|---|---|---|---|
(n = 214) | (n = 4828) | (n = 256) | ||
Maternal characteristics | ||||
Age (years) | 29 (26–33) | 30 (26–33) | 31 (28–34)** | < 0.001 |
Predelivery weight (kg) | 64 (59–72)** | 68 (63–74) | 74 (69–80)** | < 0.001 |
Height (cm) | 158 (155–160)** | 160 (157–163) | 160 (158–164)** | < 0.001 |
BMI | 25.8 (23.6–28.7)** | 26.6 (24.8–28.9) | 28.8 (26.6–30.7)** | < 0.001 |
The number of pregnancy | 2 (1–3) | 2 (1–3) | 2 (1–4)** | 0.014 |
The number of delivery | 0 (0–1) | 0 (0–1) | 1 (0–1)* | 0.004 |
Newborn information | ||||
Baby gender | ||||
Boy | 85 (39.7%)** | 2520 (52.2%) | 183 (71.5%)** | < 0.001 |
Girl | 129 (60.3%) | 2308 (47.8%) | 73 (28.5%) | |
Gestational age at birth (weeks) | 37 (37–38)** | 38 (37–39) | 39 (39–40)** | < 0.001 |
Premature infant (33–36 weeks) | 45 (21.0%)** | 418 (8.7%) | 1 (0.4%)** | < 0.001 |
The birth weight of the baby | 2355 (2195–2440)** | 3250 (2990–3510) | 4160 (4070–4300)** | < 0.001 |
Neonatal asphyxia | 0 (0%) | 15 (0.3%) | 1 (0.4%) | 0.921 |
The delivery information | ||||
Scarred uterus | 27 (12.6%) | 756 (15.7%) | 47 (18.4%) | 0.233 |
Caesarean section | 90 (42.1%)** | 1362 (28.2%) | 95 (37.1%)** | < 0.001 |
Colpoperineal laceration | 71 (33.1%)** | 2449 (50.8%) | 102 (39.9%)** | < 0.001 |
Grade I vaginal laceration | 60 (28.0%)* | 1760 (36.5%) | 58 (22.7%)** | < 0.001 |
Grade II vaginal laceration | 11 (5.1%)** | 689 (14.3%) | 44 (17.2%) | < 0.001 |
Fetal distress in uterus | 29 (13.6%) | 554 (11.5%) | 26 (10.2%) | 0.511 |
Low forceps delivery | 5 (2.3%) | 249 (5.2%) | 18 (7.0%) | 0.069 |
Diseases of pregnancy | ||||
vaginal inflammation | 25 (11.7%) | 559 (11.6%) | 36 (14.1%) | 0.484 |
Bacterial vaginosis | 6 (2.8%) | 111 (2.3%) | 15 (5.9%)** | < 0.001 |
Candida vaginosis | 20 (9.3%) | 310 (6.4%) | 18 (7.0%) | 0.229 |
Streptococcus lactis vaginitis | 2 (0.9%)* | 201 (4.2%) | 14 (5.5%) | 0.035 |
Trichomonas vaginitis | 1 (0.5%) | 6 (0.1%) | 1 (0.4%) | 0.269 |
Gestational diabetes mellitus | 46 (21.5%) | 1088 (22.5%) | 86 (33.6%)** | < 0.001 |
Hypertension | 19 (8.9%)** | 189 (3.9%) | 8 (3.1%) | < 0.001 |
Pregnancy hypertension | 12 (5.6%) | 168 (3.5%) | 6 (2.3%) | 0.148 |
Chronic hypertension | 7 (3.3%)** | 21 (0.4%) | 2 (0.8%) | < 0.001 |
Placental hypofunction | 30 (14.0%) | 554 (11.5%) | 22 (8.6%) | 0.177 |
Preeclampsia | 29 (13.6%)** | 118 (2.4%) | 7 (2.7%) | < 0.001 |
Mild preeclampsia | 12 (5.6%)** | 81 (1.7%) | 7 (2.7%) | < 0.001 |
Serious preeclampsia | 17 (7.9%)** | 37 (0.8%) | 0 (0%) | < 0.001 |
Intrahepatic cholestasis during pregnancy | 8 (3.7%) | 79 (1.6%) | 2 (0.8%) | 0.076 |
Thyroid dysfunction | 11 (5.1%) | 411 (8.5%) | 23 (9%) | 0.368 |
Virus infection | ||||
HBV | 5 (2.3%) | 111 (2.3%) | 6 (2.3%) | 0.998 |
Syphilis | 1 (0.5%) | 26 (0.5%) | 1 (0.4%) | 0.943 |
HPV | 0 (0%) | 12 (0.2%) | 1 (0.4%) | 0.688 |
Abnormal shape of placenta | 19 (8.9%) | 343 (7.1%) | 18 (7.0%) | 0.678 |
Pelvic adhesion | 3 (1.4%) | 97 (2.0%) | 6 (2.3%) | 0.761 |
Anemia | 18 (8.4%) | 562 (11.6%) | 40 (15.6%) | 0.048 |
Ultrasound data at different gestational weeks
GA | N | BPD | OFD | HC | FL | AC | ||||||||||
10th | 50th | 90th | 10th | 50th | 90th | 10th | 50th | 90th | 10th | 50th | 90th | 10th | 50th | 90th | ||
21+0 ~ 21+6 | 11 | 48 | 52 | 55 | 62 | 66 | 69 | 177 | 190 | 205 | 33 | 37 | 38 | 158 | 167 | 179 |
22+0 ~ 22+6 | 56 | 53 | 55 | 59 | 67 | 71 | 75 | 196 | 207 | 218 | 37 | 40 | 42 | 171 | 183 | 193 |
23+0 ~ 23+6 | 887 | 54 | 59 | 63 | 70 | 74 | 79 | 205 | 218 | 230 | 39 | 42 | 45 | 178 | 192 | 206 |
24+0 ~ 24+6 | 3549 | 57 | 60 | 64 | 72 | 76 | 80 | 213 | 223 | 233 | 41 | 43 | 46 | 187 | 198 | 209 |
25+0 ~ 25+6 | 684 | 59 | 62 | 66 | 75 | 79 | 83 | 221 | 231 | 242 | 43 | 45 | 48 | 194 | 206 | 217 |
26+0 ~ 26+6 | 80 | 61 | 65 | 68 | 77 | 82 | 86 | 229 | 240 | 252 | 44 | 47 | 50 | 197 | 214 | 224 |
27+0 ~ 27+6 | 31 | 58 | 68 | 73 | 74 | 87 | 91 | 218 | 254 | 264 | 42 | 50 | 52 | 195 | 226 | 240 |
28+0 ~ 28+6 | 686 | 69 | 72 | 76 | 87 | 91 | 95 | 255 | 265 | 277 | 51 | 53 | 56 | 230 | 242 | 255 |
29+0 ~ 29+6 | 1200 | 72 | 75 | 79 | 90 | 94 | 98 | 264 | 275 | 287 | 53 | 55 | 58 | 241 | 253 | 267 |
30+0 ~ 30+6 | 1708 | 74 | 77 | 81 | 92 | 96 | 101 | 272 | 282 | 293 | 55 | 57 | 60 | 250 | 262 | 275 |
31+0 ~ 31+6 | 915 | 76 | 80 | 83 | 95 | 99 | 104 | 279 | 289 | 301 | 57 | 59 | 62 | 259 | 273 | 285 |
32+0 ~ 32+6 | 789 | 78 | 82 | 86 | 97 | 102 | 106 | 286 | 297 | 309 | 59 | 61 | 63 | 267 | 282 | 295 |
33+0 ~ 33+6 | 589 | 80 | 84 | 88 | 100 | 104 | 109 | 292 | 304 | 317 | 60 | 63 | 66 | 278 | 293 | 307 |
34+0 ~ 34+6 | 1333 | 82 | 86 | 90 | 102 | 106 | 110 | 300 | 310 | 321 | 63 | 65 | 68 | 288 | 302 | 317 |
35+0 ~ 35+6 | 1386 | 85 | 88 | 92 | 104 | 108 | 112 | 306 | 316 | 328 | 64 | 67 | 69 | 297 | 312 | 327 |
36+0 ~ 36+6 | 1165 | 86 | 90 | 93 | 106 | 110 | 113 | 311 | 321 | 333 | 66 | 69 | 71 | 306 | 320 | 335 |
37+0 ~ 37+6 | 574 | 88 | 92 | 95 | 108 | 112 | 115 | 316 | 327 | 338 | 67 | 70 | 72 | 314 | 330 | 345 |
38+0 ~ 38+6 | 206 | 88 | 92 | 96 | 108 | 112 | 116 | 318 | 329 | 342 | 68 | 71 | 74 | 320 | 334 | 351 |
39+0 ~ 39+6 | 45 | 90 | 94 | 98 | 109 | 114 | 118 | 322 | 336 | 347 | 69 | 72 | 74 | 327 | 342 | 358 |
GA | N | AFI | S/D | PI | RI | PT | ||||||||||
10th | 50th | 90th | 10th | 50th | 90th | 10th | 50th | 90th | 10th | 50th | 90th | 10th | 50th | 90th | ||
21+0 ~ 21+6 | 11 | 95 | 116 | 127 | 2.95 | 3.11 | 3.80 | 1.03 | 1.11 | 1.29 | 0.66 | 0.68 | 0.74 | 21 | 22 | 25 |
22+0 ~ 22+6 | 56 | 94 | 119 | 141 | 2.46 | 2.96 | 3.59 | 0.90 | 1.08 | 1.26 | 0.60 | 0.67 | 0.72 | 21 | 24 | 28 |
23+0 ~ 23+6 | 887 | 92 | 119 | 157 | 2.38 | 3.05 | 3.84 | 0.85 | 1.08 | 1.28 | 0.58 | 0.67 | 0.74 | 20 | 25 | 31 |
24+0 ~ 24+6 | 3549 | 96 | 119 | 147 | 2.46 | 3.00 | 3.65 | 0.88 | 1.06 | 1.24 | 0.59 | 0.67 | 0.73 | 22 | 26 | 30 |
25+0 ~ 25+6 | 684 | 96 | 119 | 148 | 2.46 | 2.96 | 3.57 | 0.88 | 1.05 | 1.22 | 0.59 | 0.66 | 0.72 | 22 | 26 | 31 |
26+0 ~ 26+6 | 80 | 95 | 117 | 149 | 2.3 | 2.84 | 3.50 | 0.81 | 1.02 | 1.18 | 0.57 | 0.65 | 0.71 | 23 | 27 | 32 |
27+0 ~ 27+6 | 31 | 96 | 110 | 134 | 2.38 | 2.69 | 3.30 | 0.86 | 0.99 | 1.14 | 0.58 | 0.63 | 0.70 | 24 | 28 | 31 |
28+0 ~ 28+6 | 686 | 94 | 115 | 144 | 2.18 | 2.68 | 3.24 | 0.77 | 0.95 | 1.14 | 0.54 | 0.63 | 0.69 | 25 | 29 | 33 |
29+0 ~ 29+6 | 1200 | 92 | 112 | 143 | 2.14 | 2.62 | 3.10 | 0.75 | 0.94 | 1.09 | 0.53 | 0.62 | 0.68 | 26 | 30 | 34 |
30+0 ~ 30+6 | 1708 | 90 | 110 | 141 | 2.09 | 2.53 | 2.95 | 0.73 | 0.91 | 1.06 | 0.52 | 0.61 | 0.66 | 27 | 31 | 35 |
31+0 ~ 31+6 | 915 | 87 | 108 | 143 | 2.05 | 2.49 | 2.93 | 0.71 | 0.90 | 1.05 | 0.51 | 0.60 | 0.66 | 27 | 31 | 36 |
32+0 ~ 32+6 | 789 | 85 | 105 | 136 | 2.01 | 2.46 | 2.88 | 0.69 | 0.89 | 1.03 | 0.50 | 0.59 | 0.65 | 28 | 32 | 37 |
33+0 ~ 33+6 | 589 | 78 | 102 | 136 | 1.97 | 2.38 | 2.84 | 0.68 | 0.86 | 1.02 | 0.49 | 0.58 | 0.65 | 29 | 33 | 38 |
34+0 ~ 34+6 | 1333 | 80 | 101 | 134 | 1.92 | 2.32 | 2.79 | 0.65 | 0.84 | 1.02 | 0.48 | 0.57 | 0.64 | 29 | 33 | 38 |
35+0 ~ 35+6 | 1386 | 77 | 100 | 130 | 1.91 | 2.26 | 2.75 | 0.64 | 0.81 | 1.00 | 0.48 | 0.56 | 0.64 | 30 | 34 | 38 |
36+0 ~ 36+6 | 1165 | 78 | 99 | 130 | 1.88 | 2.24 | 2.73 | 0.63 | 0.81 | 0.99 | 0.47 | 0.55 | 0.63 | 30 | 34 | 39 |
37+0 ~ 37+6 | 574 | 76 | 98 | 135 | 1.82 | 2.18 | 2.66 | 0.60 | 0.78 | 0.97 | 0.45 | 0.54 | 0.62 | 31 | 35 | 39 |
38+0 ~ 38+6 | 206 | 71 | 99 | 135 | 1.84 | 2.16 | 2.61 | 0.61 | 0.78 | 0.98 | 0.46 | 0.54 | 0.62 | 31 | 35 | 38 |
39+0 ~ 39+6 | 45 | 63 | 90 | 125 | 1.82 | 2.11 | 2.52 | 0.61 | 0.77 | 0.96 | 0.45 | 0.53 | 0.61 | 31 | 35 | 39 |
GA | Parameters | SGA | AGA | LGA | P |
---|---|---|---|---|---|
(n = 214) | (n = 4828) | (n = 256) | |||
21+0 ~ 27+6 | BPD | 0.98 (0.95–1.00)** | 1.00 (0.97–1.03) | 1.02 (0.98–1.05)** | < 0.001 |
OFD | 0.97 (0.94–1.00)** | 1.00 (0.97–1.03) | 1.01 (0.99–1.04)** | < 0.001 | |
HC | 0.98 (0.95–1.00)** | 1.00 (0.98–1.02) | 1.02 (0.99–1.04)** | < 0.001 | |
FL | 0.98 (0.95–1.00)** | 1.00 (0.98–1.04) | 1.02 (1.00–1.05)** | < 0.001 | |
AC | 0.98 (0.94–1.00)** | 1.00 (0.97–1.03) | 1.03 (1.00–1.06)** | < 0.001 | |
AFI | 0.95 (0.84–1.06)** | 1.00 (0.89–1.12) | 1.03 (0.94–1.14)** | < 0.001 | |
S/D | 1.01 (0.89–1.16) | 1.00 (0.90–1.11) | 0.97 (0.86–1.04)** | < 0.001 | |
PI | 1.00 (0.90–1.11) | 1.00 (0.91–1.09) | 0.98 (0.88–1.05)** | < 0.001 | |
RI | 1.00 (0.94–1.07) | 1.00 (0.94–1.04) | 0.99 (0.91–1.02)** | < 0.001 | |
PT | 0.96 (0.88–1.04)** | 1.00 (0.92–1.08) | 1.04 (0.96–1.12)** | < 0.001 | |
28+0 ~ 32+6 | BPD | 0.96 (0.94–0.99)** | 1.00 (0.98–1.03) | 1.01 (1.00–1.05)** | < 0.001 |
OFD | 0.97 (0.94–0.99)** | 1.00 (0.98–1.02) | 1.02 (0.99–1.04)** | < 0.001 | |
HC | 0.96 (0.95–0.99)** | 1.00 (0.98–1.02) | 1.02 (1.00–1.04)** | < 0.001 | |
FL | 0.97 (0.95–1.00)** | 1.00 (0.98–1.03) | 1.02 (1.00–1.05)** | < 0.001 | |
AC | 0.95 (0.93–0.98)** | 1.00 (0.98–1.02) | 1.04 (1.01–1.06)** | < 0.001 | |
AFI | 0.98 (0.82–1.12)* | 1.00 (0.89–1.13) | 1.07 (0.97–1.23)** | < 0.001 | |
S/D | 1.05 (0.96–1.14)** | 1.00 (0.90–1.09) | 0.96 (0.87–1.06)** | < 0.001 | |
PI | 1.05 (0.96–1.14)** | 1.00 (0.89–1.09) | 0.96 (0.86–1.05)** | < 0.001 | |
RI | 1.03 (0.97–1.08)** | 1.00 (0.93–1.05) | 0.97 (0.90–1.03)** | < 0.001 | |
PT | 0.97 (0.90–1.06) | 1.00 (0.93–1.06) | 1.03 (0.97–1.12)** | < 0.001 | |
33+0 ~ 39+6 | BPD | 0.95 (0.93–0.98)** | 1.00 (0.98–1.02) | 1.02 (1.00–1.05)** | < 0.001 |
OFD | 0.96 (0.95–0.99)** | 1.00 (0.98–1.02) | 1.02 (1.00–1.04)** | < 0.001 | |
HC | 0.96 (0.94–0.98)** | 1.00 (0.98–1.02) | 1.02 (1.01–1.04)** | < 0.001 | |
FL | 0.96 (0.93–0.99)** | 1.00 (0.98–1.02) | 1.02 (1.00–1.03)** | < 0.001 | |
AC | 0.93 (0.91–0.96)** | 1.00 (0.98–1.02) | 1.05 (1.03–1.07)** | < 0.001 | |
AFI | 0.88 (0.77–1.01)** | 1.00 (0.89–1.15) | 1.11 (0.97–1.33)** | < 0.001 | |
S/D | 1.05 (0.96–1.19)** | 1.00 (0.91–1.11) | 0.95 (0.86–1.06)** | < 0.001 | |
PI | 1.05 (0.95–1.19)** | 1.00 (0.88–1.12) | 0.94 (0.82–1.05)** | < 0.001 | |
RI | 1.04 (0.96–1.11)** | 1.00 (0.91–1.07) | 0.96 (0.87–1.04)** | < 0.001 | |
PT | 0.97 (0.91–1.06)** | 1.00 (0.94–1.06) | 1.03 (1.00–1.11)** | < 0.001 |
Logistic regression modeling
Characteristics | β | OR | 95% CI | P | |
---|---|---|---|---|---|
X1 | Hypertension | -0.784 | 0.46 | 0.29–0.73 | 0.001 |
X2 | Preeclampsia | -0.693 | 0.5 | 0.34–0.74 | 0.001 |
X3 | OFD-M-[21, 27] | -9.377 | 0 | 0–0.01 | < 0.001 |
X4 | FL-M-[21, 27] | 7.26 | 1422 | 13.11–1.54*105 | 0.002 |
X5 | AC-M-[28, 32] | 14.578 | 2.14*106 | 1.11*104–4.16*108 | < 0.001 |
X6 | BPD-M | 14.903 | 2.97*106 | 1.04*104–8.44*108 | < 0.001 |
X7 | FL-M | 8.436 | 4609 | 11.24–1.89*106 | 0.006 |
X8 | AC-M | 26.531 | 3.33*1011 | 6.35*108–1.75*1014 | < 0.001 |
X9 | AFI-M | 2.087 | 8.06 | 3.44–18.91 | < 0.001 |
Constant | -59.496 | 0 | < 0.001 |
Characteristics | OR | 95% CI | P |
---|---|---|---|
Hypertension | 0.43 | 0.30–0.62 | < 0.001 |
Preeclampsia | 0.28 | 0.22–0.37 | < 0.001 |
OFD-M-[21, 27] | 1.92*106 | 5.12*104–7.21*107 | < 0.001 |
FL-M-[21, 27] | 2.95*105 | 1.13*107–7.68*109 | < 0.001 |
AC-M-[28, 32] | 1.14*1015 | 2.03*1013–6.42*1016 | < 0.001 |
BPD-M | 5.73*1016 | 6.96*1014–4.72*1018 | < 0.001 |
FL-M | 6.43*1015 | 1.06*1014–3.90*1017 | < 0.001 |
AC-M | 2.49*1020 | 2.43*1018–2.55*1022 | < 0.001 |
AFI-M | 26.67 | 13.49–52.72 | < 0.001 |
Prediction of SGA neonate by SGAp
Characteristic | SGA | non-SGA | p |
---|---|---|---|
median (IQR) | median (IQR) | ||
SGA born at any stage (N) | 214 | 5084 | |
SGAp | 0.96 (-0.47–2.39) | 5.14 (3.91–6.36) | < 0.001 |
AC-M | 0.93 (0.91–0.96) | 1.00 (0.98–1.03) | < 0.001 |
EFW-M | 0.84 (0.79–0.90) | 1.00 (0.95–1.06) | < 0.001 |
EFW-M plus MF | 34.56 (33.42–36.12) | 38.38 (37.19–39.56) | < 0.001 |
SGA born within 2 weeks (N) | 120 | 1459 | |
SGAp | 0.61 (-0.79–1.93) | 5.08 (3.91–6.35) | < 0.001 |
AC-M | 0.93 (0.91–0.96) | 1.00 (0.98–1.03) | < 0.001 |
EFW-M | 0.82 (0.78–0.89) | 1.01 (0.95–1.06) | < 0.001 |
EFW-M plus MF | 34.35 (33.40–35.68) | 38.43 (37.28–39.62) | < 0.001 |
Screening test | DR at 5% FPR (%) | DR at 10% FPR (%) |
---|---|---|
SGA born at any stage | ||
SGAp | 70.6 (67.4–73.7) | 80.4 (77.7–83.1) |
AC-M | 60.7 (57.4–64.1) | 69.6 (66.5–72.8) |
EFW-M | 66.4 (63.1–69.6) | 73.8 (70.8–76.8) |
EFW-M plus MF | 67.8 (64.6–71.0) | 74.3 (71.3–77.3) |
SGA born within 2 weeks | ||
SGAp | 74.2 (70.2–78.2) | 85.8 (82.7–89.0) |
AC-M | 66.7 (62.4–71.0) | 75.8 (71.9–79.7) |
EFW-M | 70.8 (66.7–75.0) | 80.0 (76.3–83.7) |
EFW-M plus MF | 72.5 (68.4–76.6) | 82.5 (79.0–86.0) |
screening test | FPR for 85% DR (%) | FPR for 90% DR (%) | FPR for 95% DR (%) |
---|---|---|---|
SGA born at any stage | |||
SGAp | 11.8 (11.3–12.3) | 16.4 (15.9–17.0) | 27.8 (27.1–28.4) |
AC-M | 22.0 (21.4–22.6) | 29.9 (29.3–30.6) | 38.7 (38.1–39.4) |
EFW-M | 19.3 (18.7–19.8) | 24.4 (23.8–25.1) | 33.1 (32.5–33.8) |
EFW-M plus MF | 17.2 (16.7–17.8) | 20.9 (20.3–21.5) | 31.1 (30.5–31.8) |
SGA born within 2 weeks | |||
SGAp | 9.4 (8.6–10.2) | 12.4 (11.5–13.3) | 22.0 (20.9–23.1) |
AC-M | 13.2 (12.3–14.1) | 23.0 (21.9–24.1) | 32.7 (31.5–33.9) |
EFW-M | 13.1 (12.2–14.0) | 18.0 (17.0–19.0) | 26.2 (25.0–27.3) |
EFW-M plus MF | 12.6 (11.7–13.5) | 17.0 (16.0–18.0) | 26.1 (25.0–27.3) |