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. 2023 Dec 4;23:836. doi: 10.1186/s12884-023-06136-w

Table 2.

Comparison of pregnancy characteristics between study and reference groups

Study group
(n = 112)
Reference group
(n = 224)
P value
ART (%) 9.4 (12) 2.2 (5) 0.001#
Gestation age at birth (weeks) 37.9 ± 1.6 39.3 ± 1.2 0.000&
Gestation age at birtha (weeks) 38.6 ± 0.9 39.4 ± 1.0 0.000&
Cervical incompetence 1/112 0/224 /
PROM (%/n) 21.4 (24) 25.4 (57) 0.417#
CAN (%/n) 54.5 (61) 29.9 (67) 0.000#
CAN three times (%/n) 7.1 (8) 0.4 (1) 0.001§
Manual placenta removal (%/n) 9.8 (11) 4.0 (9) 0.034#
Postpartum hemorrhage (%/n) 2.7 (3) 4.5 (10) 0.617§
Uterotonic usage (%/n) 40.2 (45) 37.5 (84) 0.634#
Oligohydramnios (%/n) 3.6 (4) 0.9 (2) 0.098§
Hypertensive disorders (%/n) 4.5 (5) 6.7 (15) 0.415#
Gestational diabetes (%/n) 17.0 (19) 14.7 (33) 0.594#
ICP (%/n) 2.7 (3) 1.3 (3) 0.404*
Placenta previa (%/n) 2.7 (3) 0.4(1) 0.110*
Placental abruption (%/n) 0.9 (1) 1.8 (4) 0.668*

Data are presented as percent (numbers) or mean ± SD

ART, assisted reproductive technology; PROM, premature rupture of membranes; CAN, cord-around-the neck; ICP, intrahepatic cholestasis of pregnancy

a Excluding the preterm births

# Chi-squared test *Fisher’s exact test §Yates correction for continuity

&Student’s t-test