Table 3.
Risks of placental features for spontaneous preterm and iatrogenic preterm birth compared to spontaneous term birth.
| Pathology variable | OR SPTB vs STB |
CI lower SPTB vs STB |
CI upper SPTB vs STB |
SPTB (141) n (% YES) of variable |
STB (876) n (% YES) of variable |
IPTB (84) n (% YES) of variable |
OR IPTB vs STB |
CI lower IPTB vs STB |
CI upper IPTB vs STB |
|---|---|---|---|---|---|---|---|---|---|
| Features of maternal vascular malperfusion | |||||||||
| Small trimmed placenta for GA | 0.79 | 0.55 | 1.12 | 66 (47%) | 456 (53%) | 49 (59%) | 1.29 | 0.81 | 2.03 |
| Macroscopic pathological infarction | 3.25 | 1.43 | 7.39 | 9 (6%) | 18 (2%) | 9 (11%) | 5.80 | 2.52 | 13.36 |
| Microscopic pathological infarction | 1.85 | 1.09 | 3.14 | 20 (14%) | 72 (8%) | 26 (31%) | 5.01 | 2.97 | 8.43 |
| Decidual arteriopathy | 1.68 | 0.94 | 3.00 | 16 (11%) | 62 (7%) | 22 (26%) | 4.66 | 2.69 | 8.08 |
| Accelerated villous maturation | 17.94 | 9.09 | 35.42 | 30 (21%) | 13 (1%) | 43 (51%) | 69.62 | 34.75 | 139.50 |
| Increased syncytial knots | 0.37 | 0.25 | 0.55 | 42 (30%) | 466 (53%) | 52 (62%) | 1.43 | 0.90 | 2.26 |
| Distal villous hypoplasia | 0.98 | 0.52 | 1.85 | 12 (9%) | 76 (9%) | 29 (35%) | 5.55 | 3.34 | 9.22 |
| Increased extravillous trophoblast | 0.55 | 0.35 | 0.86 | 26 (18%) | 255 (29%) | 28 (33%) | 1.22 | 0.76 | 1.96 |
| Increased perivillous fibrin | 0.42 | 0.29 | 0.62 | 42 (30%) | 439 (50%) | 46 (55%) | 1.21 | 0.77 | 1.89 |
| Features of abruption | |||||||||
| Macroscopic abruption | 1.59 | 0.88 | 2.88 | 15 (11%) | 61 (7%) | 16 (19%) | 3.14 | 1.72 | 5.75 |
| Microscopic abruption | 2.19 | 1.37 | 3.50 | 28 (20%) | 89 (10%) | 20 (24%) | 2.76 | 1.60 | 4.78 |
| Acute placental abruption (both) | 2.08 | 1.00 | 4.34 | 10 (7%) | 31 (4%) | 11 (13%) | 4.11 | 1.98 | 8.51 |
| Features of fetal vascular malperfusion | |||||||||
| Thrombosis of cord vessels (microscopic) | 0.88 | 0.20 | 3.93 | 2 (1%) | 14 (2%) | 6 (7%) | 4.85 | 1.81 | 12.98 |
| Avascular villi | 0.77 | 0.48 | 1.22 | 24 (17%) | 185 (21%) | 28 (33%) | 1.87 | 1.15 | 3.02 |
| Chorionic plate/stem villus thrombosis | 0.75 | 0.39 | 1.44 | 11 (8%) | 89 (10%) | 10 (12%) | 1.19 | 0.60 | 2.40 |
| Villous-stromal karyorrhexis | 0.47 | 0.29 | 0.76 | 22 (16%) | 246 (28%) | 25 (30%) | 1.09 | 0.66 | 1.77 |
| Fetal vascular thrombosis | 0.57 | 0.31 | 1.04 | 13 (9%) | 132 (15%) | 24 (29%) | 2.25 | 1.35 | 3.74 |
| Vascular necrosis | 991.00 | 992.00 | 993.00 | 0 (0%) | 8 (1%) | 1 (1%) | 1.34 | 0.17 | 10.82 |
| Inflammatory response | |||||||||
| Chorioamnionitis (MIR) | 1.40 | 0.97 | 2.02 | 56 (40%) | 280 (32%) | 25 (30%) | 0.90 | 0.55 | 1.47 |
| Villitis (MIR) | 1.33 | 0.89 | 2.00 | 38 (27%) | 190 (22%) | 19 (23%) | 1.06 | 0.62 | 1.80 |
| Funisitis of cord (FIR) | 2.24 | 1.19 | 4.23 | 14 (10%) | 41 (5%) | 1 (1%) | 0.25 | 0.03 | 1.85 |
| Vasculitis of cord vessels (FIR) | 1.58 | 0.86 | 2.92 | 14 (10%) | 57(7%) | 4 (5%) | 0.74 | 0.26 | 2.08 |
| Outcome | |||||||||
| Intrauterine growth restriction | 0.45 | 0.24 | 0.83 | 12 (9%) | 163 (19%) | 25 (33%) | 2.18 | 1.31 | 3.63 |
| Low birthweight | 30.16 | 19.32 | 47.10 | 99 (72%) | 68 (8%) | 69 (85%) | 68.32 | 35.27 | 132.34 |
| Stillbirths | 20.51 | 9.68 | 43.48 | 27 (19%) | 10 (1%) | 26 (31%) | 38.82 | 17.86 | 84.37 |
| Infant demises before one year | 9.48 | 3.55 | 25.33 | 10 (7%) | 7 (1%) | 4 (5%) | 6.21 | 1.78 | 21.66 |
SPTB, spontaneous preterm birth; IPTB, iatrogenic preterm birth; STB, spontaneous term birth; OR, odds ratio; CI, confidence interval; Bold indicates significant OR; MIR, maternal inflammatory response; FIR, fetal inflammatory response; vs, versus.