Table 2 Pregnancy and Delivery Characteristics

Pregnancy-induced hypertension

3 (0.57 %)

1 (1.59 %) P = 0.365^a

3 (7.14 %) P < 0.001^a

Placental abruption

2 (0.38 %)

0 P = 1.00^a

1 (2.38 %) P = 0.205^a

Placenta previa

4 (0.75 %)

2 (3.17 %) P = 0.126^a

0 P = 1.00^a

Prolonged gravidarum (>42 w)

39 (7.36 %)

6 (9.52 %) P = 0.612^a

1 (2.38 %) P = 0.346^a

Female fetus

261 (49.25 %)

30 (47.62 %) P = 0.807

23 (54.76 %) P = 0.491

Isoimmunization (Rh)

1 (0.19 %)

0 P = 1.00^a

0 P = 1.00^a

Low hemoglobin concentration (< 100 g/L)

7 (1.32 %)

0 P = 1.00^a

0 P = 1.00^a

Cesarean delivery

97 (18.30 %)

9 (14.29 %) P = 0.432

14 (33.33 %) P = 0.018

Forceps/vacuum

47 (8.87 %)

7 (11.11 %) P = 0.558

2 (4.76 %) P = 0.566^a

Bloody amniotic fluid

11 (2.07 %)

2 (3.17 %) P = 0.638^a

2 (4.76 %) P = 0.246^a

Meconium-stained amniotic fluid

73 (13.75 %)

9 (14.29 %) P = 0.907

4 (9.52 %) P = 0.440

Placental/fetal mass ratio (%)

16.6 %

16.2 % P = 0.51^b

17.8 % P = 0.46^b