True umbilical cord knot detection via active scanning: a prospective study on accuracy and visualization factors

Table 2 The clinical characteristics of the three groups grouped according to the UCUIQ

characteristics	scale 1 (n = 183)	scale 2 (n = 72)	scale 3 (n = 118)	P -Value
Maternal age(year)	29.72 ± 4.31	30.10 ± 4.22	30.11 ± 4.53	0.690
Gestational age(week) ^∗	22.70 ± 4.54	13.32 ± 3.53	33.20 ± 5.47	< 0.001
BMI before pregnancy(kg/m²)	20.90 ± 2.61	20.92 ± 2.78	21.41 ± 3.18	0.271
BMI at the US survey (kg/m²) ^∗	23.27 ± 2.95	21.33 ± 3.03	25.43 ± 3.46	< 0.001
Maximum amniotic fluid depth(mm) ^∗	49.38 ± 8.84	40.06 ± 5.31	45.43 ± 9.84	< 0.001
Maximum cross-sectional area of UC(cm²) ^∗	1.38 ± 0.63	0.29 ± 0.40	2.07 ± 0.63	< 0.001
Placental position in uterus				0.190
Anterior wall	86	30	58	0.838
Posterior wall	90	38	56
The other wall	7	4	4

^*Indicates difference between groups (P < 0.017 after Bonferonni adjustment). BMI Body Mass Index, cm² square centimeter, kg/m² kilogram per square meter, US ultrasound, UC umbilical cord, UCUIQ umbilical cord ultrasonic image quality

ISSN: 1471-2393