Independent risk factors for twin pregnancy adverse fetal outcomes before 28 gestational week by first trimester ultrasound screening

Table 3 Comparison of first trimester screening results and personal history between the abnormal group and the control group

Characteristics	Abnormal group (n = 29)	Control group (n = 97)	P value
Maternal age (years)	32.39 ± 3.65	31.62 ± 4.07	0.333
Maternal age (≥ 35 years)	6 (20.69)	28 (28.87)	0.384
Assisted conception	11 (37.93)	46 (47.42)	0.368
Systolic blood pressure	113.17 ± 9.74	111.24 ± 9.77	0.351
Diastolic blood pressure	73.00 ± 7.40	71.82 ± 8.01	0.482
Mean arterial pressure	86.39 ± 7.59	84.96 ± 7.74	0.383
High blood pressure	3 (10.34)	8 (8.25)	0.714
BMI (kg/m2)	22.42 ± 3.40	22.21 ± 3.13	0.753
BMI ≥ 24 kg/m2	6 (20.69)	30 (30.93)	0.284
BMI ≥ 30 kg/m2	1 (3.44)	2 (2.06)	0.547
History of hysteroscopy	8 (27.59)	29 (29.90)	0.811
History of anti-phospholipid syndrome	2 (6.90)	2 (2.06)	0.333
Family history of high blood pressure	6 (20.69)	30 (30.93)	0.284
Nulliparous	16 (55.17)	47 (48.45)	0.525
Chorionicity			0.009
Dichorionic diamniotic	16 (55.17)	77 (79.38)
Monochorionic diamniotic	13 (44.83)	20 (20.62)
Mean PI of bilateral uterine arteries	1.57 ± 0.55	1.28 ± 0.42	0.003
Mean RI of bilateral uterine arteries	0.71 ± 0.11	0.65 ± 0.11	0.008
Early diastolic notch in bilateral uterine arteries	10 (34.48)	15 (15.46)	0.024
Early diastolic notch in at least one uterine artery	15 (51.72)	39 (40.21)	0.271
Abnormal ultrasound findings during first trimester screening	13 (44.83)	2 (2.06)	< 0.001
Crown-rump length discordance ≥ 10%	3 (3/20, 15)	6 (6.19)	0.181

Data are given as mean ± standard error or n (%). BMI: Body mass index; PI: Pulsatility index; RI: Resistance index.