Table 5. Placental findings in preterm (24–36 weeks) stillbirths and live births small, average, and large for gestational age.1/.
| Characteristic, column % or as shown 2/ | SGA | AGA | LGA | P-value for association, SBs & LBs separately3/ |
P-value for interaction 4/ |
|---|---|---|---|---|---|
| Unweighted number of stillbirths | 122 | 87 | 22 | ||
| Weighted number of stillbirths | 121 | 84 | 22 | ||
| Unweighted number of live births | 46 | 113 | 18 | ||
| Weighted number of live births | 23 | 58 | 13 | ||
| DEVELOPMENTAL DISORDERS | |||||
| Umbilical cord | |||||
| Single umbilical artery | 0.24* | ||||
| Stillbirths | 8.4 | 10.7 | 10.8 | 0.85 | |
| Live births | 3.0 | 1.1 | 0.0 | 0.41 | |
| Velamentous insertion | 0.47* | ||||
| Stillbirths | 5.2 | 4.7 | 0.0 | 0.03 | |
| Live births | 2.9 | 2.4 | 0.0 | 0.21 | |
| Furcate insertion | 0.07* | ||||
| Stillbirths | 1.7 | 1.5 | 0.0 | 0.26 | |
| Live births | 0.0 | 2.2 | 8.7 | 0.27 | |
| Placental membranes | |||||
| Circummarginate insertion | 0.99 | ||||
| Stillbirths | 10.6 | 14.9 | 22.0 | 0.38 | |
| Live births | 4.8 | 7.3 | 12.1 | 0.73 | |
| Circumvallate insertion | 0.21* | ||||
| Stillbirths | 2.3 | 3.0 | 3.8 | 0.91 | |
| Live births | 0.0 | 1.6 | 0.0 | 0.32 | |
| Fetal villous capillaries | |||||
| Terminal villous immaturity (diffuse) | 0.009* | ||||
| Stillbirths | 7.3 | 8.1 | 19.6 | 0.44 | |
| Live births | 7.2 | 1.7 | 0.0 | 0.22 | |
| Terminal villous hypoplasia (diffuse) | 0.17* | ||||
| Stillbirths | 7.1 | 0.0 | 0.0 | 0.03 | |
| Live births | 10.8 | 1.7 | 0.0 | 0.21 | |
| INFLAMMATORY DISORDERS | |||||
| Maternal inflammatory response | |||||
| Acute chorioamnionitis—placental membranes | 0.87 | ||||
| Stillbirths | 28.7 | 19.4 | 16.7 | 0.22 | |
| Live births | 26.5 | 12.5 | 14.3 | 0.71 | |
| Acute chorioamnionitis—chorionic plate | 0.95 | ||||
| Stillbirths | 16.3 | 13.1 | 20.1 | 0.68 | |
| Live births | 21.8 | 15.0 | 28.1 | 0.63 | |
| Fetal inflammatory response | |||||
| Acute funisitis | 0.55* | ||||
| Stillbirths | 2.7 | 4.1 | 0.0 | 0.06 | |
| Live births | 2.6 | 4.0 | 0.6 | 0.13 | |
| Acute umbilical cord arteritis | 0.69* | ||||
| Stillbirths | 0.0 | 0.0 | 4.6 | 0.60 | |
| Live births | 1.5 | 3.0 | 3.9 | 0.60 | |
| Acute umbilical cord phlebitis | 0.83 | ||||
| Stillbirths | 0.7 | 2.8 | 4.6 | 0.42 | |
| Live births | 2.1 | 3.9 | 10.5 | 0.43 | |
| Chorionic plate acute vasculitis | 0.22 | ||||
| Stillbirths | 1.6 | 2.8 | 3.4 | 0.80 | |
| Live births | 1.9 | 8.4 | 0.6 | 0.10 | |
| Chorionic plate vascular degenerative changes | 0.99* | ||||
| Stillbirths | 3.4 | 7.5 | 11.1 | 0.26 | |
| Live births | 0.0 | 0.2 | 0.0 | 0.61 | |
| Villitis | |||||
| Acute diffuse villitis | 0.88* | ||||
| Stillbirths | 1.5 | 0.9 | 0.0 | 0.27 | |
| Live births | 0.0 | 0.1 | 0.0 | 0.61 | |
| Chronic diffuse villitis | 0.44* | ||||
| Stillbirths | 3.4 | 0.0 | 0.0 | 0.14 | |
| Live births | 2.5 | 0.3 | 0.0 | 0.23 | |
| CIRCULATORY DISORDERS | |||||
| Maternal circulatory disorders | |||||
| Retroplacental hematoma | 0.03* | ||||
| Stillbirths | 26.7 | 16.9 | 0.0 | <0.001 | |
| Live births | 5.7 | 2.7 | 15.3 | 0.39 | |
| Parenchymal infarction | 0.40 | ||||
| Stillbirths | 48.1 | 25.9 | 14.6 | <0.001 | |
| Live births | 17.6 | 16.1 | 7.2 | 0.52 | |
| Intraparenchymal thrombus | 0.34 | ||||
| Stillbirths | 17.9 | 23.2 | 25.4 | 0.58 | |
| Live births | 14.4 | 11.1 | 34.6 | 0.32 | |
| Perivillous, intervillous fibrin, fibrinoid deposition | 0.43 | ||||
| Stillbirths | 14.8 | 8.1 | 5.8 | 0.25 | |
| Live births | 6.4 | 1.7 | 0.3 | 0.34 | |
| Fetal circulatory disorders | |||||
| Fetal vascular thrombi in the chorionic plate | 0.91 | ||||
| Stillbirths | 21.8 | 26.9 | 33.3 | 0.51 | |
| Live births | 8.8 | 9.4 | 8.8 | 1.00 | |
| Avascular villi | 0.04* | ||||
| Stillbirths | 19.3 | 21.3 | 16.8 | 0.87 | |
| Live births | 4.6 | 8.4 | 0.0 | 0.09 | |
| Placental edema | 0.01* | ||||
| Stillbirths | 3.2 | 2.3 | 11.1 | 0.51 | |
| Live births | 0.5 | 3.8 | 0.0 | 0.15 | |
| Placental weight | 0.66 [0.90] | ||||
| Stillbirths | <0.001 [<0.001] | ||||
| Median (IQR) | 180 (134–247) | 281 (208–390) | 421 (306–513) | ||
| Live births | <0.001 [<0.001] | ||||
| Median (IQR) | 318 (234–330) | 361 (301–425) | 483 (396–573) | ||
| Ratio birth weight/placental weight | 0.32 [0.40] | ||||
| Stillbirths | 0.62 [0.45] | ||||
| Median (IQR) | 5.5 (4.1–7.7) | 6.1 (4.6–7.0) | 6.0 (4.7–7.6) | ||
| Live births | 0.17 [0.44] | ||||
| Median (IQR) | 6.1 (5.9–6.9) | 6.8 (5.7–7.8) | 6.5 (5.9–7.4) |
1/ Birth weight percentiles for GA were determined using Hadlock ultrasound norms and GA at death (stillbirths) or delivery (live births) by the SCRN algorithm.
2/ Weighted percentages and other statistics are shown. For stillbirths, information was missing as follows (unweighted n): single umbilical artery, 1; velamentous insertion, 2; furcate insertion, 3; circummarginate insertion, 8; circumvallate insertion, 8; terminal villous immaturity, 3; terminal villous hypoplasia, 3; any developmental disorder, 12; acute chorioamnionitis—chorionic plate, 2; acute funisitis, 1; acute umbilical cord arteritis, 5; acute umbilical cord phlebitis, 3; chorionic plate acute vasculitis, 7; chorionic plate vascular degenerative changes, 7; acute diffuse villitis, 1; chronic diffuse villitis, 2; any inflammatory disorder, 10; retroplacental hematoma, 4; parenchymal infarction, 3; intraparenchymal thrombus, 2; perivillous, intervillous fibrin, fibrinoid deposition, 12; any maternal circulatory disorder, 8; fetal vascular thrombi in the chorionic place, 5; avascular villi, 2; edema, 6; any fetal circulatory disorder, 6; placental weight, 3; ratio birth weight/placental weight, 3. For live births, information was missing as follows (unweighted n): velamentous insertion, 4; furcate insertion, 5; circummarginate insertion, 8; circumvallate insertion, 8; terminal villous immaturity, 1; terminal villous hypoplasia, 3; any developmental disorder, 13; acute chorioamnionitis—placental membranes, 2; acute chorioamnionitis—chorionic plate, 2; acute umbilical cord arteritis, 4; chorionic plate acute vasculitis, 1; chorionic plate vascular degenerative changes, 1; acute diffuse villitis, 2; chronic diffuse villitis, 2; any inflammatory disorder, 1; retroplacental hematoma, 1; parenchymal infarction, 1; intraparenchymal thrombus, 1; perivillous, intervillous fibrin, fibrinoid deposition, 14; any maternal circulatory disorder, 10; fetal vascular thrombi in the chorionic plate, 1; avascular villi, 1; any fetal circulatory disorder, 1.
3/ P-value by the adjusted Wald F test for an association between a placental finding and birth weight percentile among stillbirths and live births separately. For each continuous measurement, the test is for mean difference in weighted ranks; p-values after adjustment for GA (24–31, 32–36) are shown in brackets.
4/ P-value by the adjusted Wald F test for whether the association between a placental finding and birth weight percentile differs for stillbirths and live births. For each continuous measure, the test was based on weighted ranks; p-values after adjustment for GA (24–31, 32–36) are shown in brackets.
* None of the births in one or more group had the placental finding. The p-value reported was estimated as described in Statistical Analysis.