Predictive model for postpartum hemorrhage requiring hysterectomy in a minority ethnic region

Table 1 Comparison of clinical data between two groups of cases

Parameters	Hysterectomy group, n = 74	Non-hysterectomy group, n = 990	χ2/t	P value
Age in yr	34.51 ± 4.31	31.10 ± 5.59	6.790	0.000
Number of pregnancies	4.12 ± 1.97	3.06 ± 2.52	-0.230	0.818
Number of deliveries	2.43 ± 1.04	1.46 ± 1.93	-5.491	0.000
Advanced maternal age	38 (51.35)	6123 (26.15)	21.161	0.000
Assisted reproductive technology	5 (6.76)	1369 (5.85)	0.106	0.802
Macrosomia	0 (0.00)	819 (3.50)	5.261	0.087
Twins	3 (4.05)	999 (4.27)	0.008	0.928
History of cesarean section	45 (60.81)	7312 (31.23)	27.270	0.000
History of adverse obstetric or perinatal events	27 (36.49)	4212 (17.99)	14.110	0.000
Non-cephalic presentation	30 (40.54)	6580 (28.10)	5.255	0.027
Stillbirth	0 (0.00)	146 (0.62)	0.924	0.708
Uterine fibroids	0 (0.00)	336 (1.43)	2.136	0.434
Placenta previa	51 (68.92)	1273 (5.44)	206.070	0.000
Nuchal cord	22 (29.73)	6166 (26.33)	0.428	0.597
Pre-pregnancy hypertension	1 (1.35)	858 (3.66)	1.465	0.375
Gestational hypertension	1 (1.35)	549 (2.34)	0.374	0.731
Eclampsia	5 (6.76)	1084 (4.63)	0.666	0.586
HELLP syndrome	0 (0.00)	19 (0.08)	0.120	0.729
Gestational diabetes	4 (5.41)	1802 (7.70)	0.603	0.526
Pre-pregnancy diabetes	4 (5.41)	1931 (8.25)	0.888	0.414
History of pelvic inflammatory disease	5 (6.76)	1165 (4.98)	0.445	0.588
History of vaginitis	2 (2.70)	1703 (7.27)	2.961	0.129
History of endometrial infection	2 (2.70)	545 (2.33)	0.043	0.835
Thrombocytopenia	1 (1.35)	250 (1.07)	0.052	0.820
Polyhydramnios	0 (0.00)	159 (0.68)	1.007	0.694
Oligohydramnios	2 (2.70)	1529 (6.53)	2.244	0.182
Post-term pregnancy	4 (5.41)	3751 (16.02)	13.396	0.005
Intrahepatic cholestasis of pregnancy	1 (1.35)	620 (2.65)	0.585	0.546
Induced labor	0 (0.00)	857 (3.66)	5.509	0.069
Preterm birth	32 (43.24)	2817 (12.03)	44.585	0.000
Premature rupture of membranes	5 (6.76)	3445 (14.71)	4.514	0.034
Placental abruption	1 (1.35)	131 (0.56)	0.594	0.441
Uterine atony	63 (85.14)	3036 (12.97)	197.174	0.000
Uterine rupture	2 (2.70)	81 (0.35)	4.739	0.028
Retained placenta	1 (1.35)	10 (0.04)	4.894	0.034
Placenta accreta	26 (35.14)	271 (1.16)	134.759	0.000
Placenta adhesion	53 (71.62)	13537 (57.81)	6.035	0.018
Perineal tears	0 (0.00)	223 (0.95)	1.414	0.649
Cesarean delivery	46 (62.16)	13479 (57.56)	4.547	0.482

Data are n (%) or mean ± standard deviation. HELLP: Hemolysis, Elevated Liver enzymes and Low Platelets.

Table 2 Binary logistic regression analysis of factors related to hysterectomy

Parameters	β	SE	Wald χ2	P value	OR	OR (95%CI)
Age	0.042	0.023	3.153	0.076	1.043	0.996-1.092
Number of deliveries	0.493	0.123	16.136	0.000	1.637	1.287-2.083
History of cesarean section	0.601	0.260	5.341	0.021	1.824	1.096-3.036
History of adverse obstetric or perinatal events	0.475	0.266	3.189	0.074	1.607	0.955-2.706
Placenta previa	2.237	0.284	61.853	0.000	9.367	5.364-16.359
Uterine atony	2.663	0.345	59.598	0.000	14.343	7.294-28.202
Placenta accreta	1.505	0.292	26.559	0.000	4.504	2.541-7.984
Constant	-10.565	0.872	146.709	0.000	0.000

CI: Confidence interval; OR: Odds ratio; SE: Standard error.

Table 3 Comparison of predictive ability of models and single parameters for hysterectomy

Parameters	AUC	AUC (95%CI)	Cut off value	Sensitivity, %	Specificity, %	Youden index
Model	0.953	0.928-0.978	0.003	90.50	90.70	0.812
Number of deliveries	0.760	0.707-0.813	1.5	89.20	55.20	0.444
History of cesarean section	0.648	0.583-0.712	Yes	60.80	68.70	0.295
Placenta previa	0.817	0.754-0.881	Yes	68.90	84.50	0.534
Uterine atony	0.861	0.814-0.908	Yes	85.10	87.00	0.721
Placenta accreta	0.670	0.594-0.745	Yes	35.10	88.80	0.239

AUC: Area under the curve; CI: Confidence interval.