Results
PTB, sPTB, abortion
OBESE

A total of 253 from 8,168 women were included in this analysis. We excluded 71 women due to missing information, and 7844 singleton women (

Patient enrolment flowchart.

The incidence of twin pregnancy in the P5 screening phase was 3.5%, with 157 dichorionic diamniotic twins (62%), and 96 monochorionic diamniotic twins (38%). Approximately 70.8% (179/253) of the women were between 20 and 34 years old, and 86.9% (220/253) had studied less than 11 years. Most of the women, 53.4% (135/253), were non-white, and 32.8% (83/253) were obese (body mass index, BMI > 30). Considering obstetrical history, 58.5% (148/253) had at least one previous pregnancy, 7.5% (19/253) had at least one previous PTB, and 24.9% (63/253) had a previous abortion. Funneling was present in 10.7% (27/253), and 13.4% (34/253) presented sludge at measurement. The rate of PTB was 73.9% (187/253), with 33.6% of sPTB < 37 weeks (85/253), and 15% (38/253) of sPTB < 34 weeks (
