Table-2.
Univariate and multivariate generalized linear mixed models for association between potential risk factors and intrapartum stillbirth (n=1372).
| Factors | Intrapartum stillbirth rate (%) | Univariate analysis | Multivariate analysis |
|---|---|---|---|
|
|
|
||
| OR; 95% CI, p | OR; 95% CI, p | ||
| PN=2–5 | 5.0 (36/718) | 1 | |
| PN=1 | 6.1 (11/181) | 1.23; 0.55–2.76; 0.610 | |
| PN=6–8 | 7.2 (34/473) | 1.45; 0.82–2.57; 0.196 | |
| GL=114–117 days | 5.0 (54/1081) | 1 | 1 |
| GL=118–120 days | 8.5 (14/165) | 1.80; 0.88–3.70; 0.109 | 2.06; 1.00–4.21; 0.049 |
| GL=112–113 days | 10.3 (13/126) | 2.23; 1.04–4.77; 0.040 | 2.36; 1.09–5.04; 0.026 |
| LS=11–13 | 1.7 (3/178) | 1 | 1 |
| LS=5–10 | 3.6 (2/55) | 2.22; 0.33–14.84; 0.411 | 3.08; 0.45–21.19; 0.252 |
| LS=14–21 | 6.7 (76/1139) | 4.26; 1.26–14.37; 0.019 | 4.26; 1.24–14.68; 0.021 |
| F | 6.3 (41/651) | 1 | |
| M | 5.5 (40/721) | 0.86; 0.54–1.35; 0.509 | |
| BO≤5 | 4.0 (16/399) | 1 | 1 |
| BO=6–10 | 5.6 (27/482) | 1.42; 0.75–2.70; 0.279 | 1.64; 0.85–3.16; 0.142 |
| BO=11–21 | 7.7 (38/491) | 2.06; 1.12–3.78; 0.021 | 2.26; 1.19–4.28; 0.013 |
| CRL=24–30 cm | 5.0 (53/1050) | 1 | |
| CRL>30 cm | 7.6 (15/198) | 1.43; 0.76–2.68; 0.264 | |
| CRL=16–24 cm | 10.5 (13/124) | 2.63; 1.31–5.30; 0.007 | |
| BW=1.0–2.1 kg | 5.1 (61/1185) | 1 | |
| BW=0.3–1.0 kg | 9.9 (15/151) | 2.33; 1.23–4.43; 0.010 | |
| BW>2.1 kg | 13.9 (5/36) | 2.65; 0.91–7.76; 0.074 | |
| BMI>15 | 5.4 (70/1291) | 1 | |
| BMI≤15 | 13.6 (11/81) | 3.15; 1.48–6.74; 0.003 | |
| PI=54–89 | 5.1 (59/1165) | 1 | 1 |
| PI>89 | 9.2 (8/87) | 2.22; 0.96–5.13; 0.061 | 1.89; 0.80–4.44; 0.145 |
| PI≤54 | 11.7 (14/120) | 2.45; 1.27–4.72; 0.007 | 2.64; 1.33–5.26; 0.006 |
| BI≤20 min | 5.4 (61/1130) | 1 | |
| BI=20-40 min | 7.6 (12/158) | 1.47; 0.76–2.84; 0.252 | |
| BI>40 min | 9.5 (8/84) | 2.00; 0.90–4.48; 0.090 | |
| CFD≤90 min | 5.6 (38/683) | 1 | |
| CFD=90–180 min | 6.0 (30/503) | 1.18; 0.70–1.99; 0.527 | |
| CFD>180 min | 7.0 (13/186) | 1.48; 0.72–3.05; 0.281 | |
| BWD=0.1–0.6 kg | 3.3 (16/488) | 1 | 1 |
| BWD=−0.5–0.1 kg | 6.3 (50/789) | 2.01; 1.12–3.60; 0.019 | 2.28; 1.25–4.14; 0.007 |
| BWD>0.6 kg | 14.8 (4/27) | 4.94;1.41–17.27; 0.012 | 4.76; 1.34–16.85; 0.016 |
| BWD<−0.5 kg | 16.2 (11/68) | 6.38; 2.71–15.02; <0.001 | 6.57; 2.71–15.91; <0.001 |
OR=Odds ratio, CI=Confidence interval, P=Probability level, PN=Parity number, GL=Gestation length, LS=Litter size, F=Female piglet, M=Male piglet, BO=Birth order, CRL=Crown-rump length, BW=Birth weight, BMI=Body mass index, PI=Ponderal index, BI=Birth interval, CFD=Cumulative farrowing duration, BWD=Birth weight deviation. The p-value, marginal R2 and conditional R2 of the final model were <0.001, 0.184 and 0.241, respectively. Hosmer-Lemeshow goodness of fit test had a p=0.175. Cramer’s V coefficients between selected independent variables ranged between 0.02 and 0.14