Research Calculators

Research Calculators

Spontaneous preterm birth prediction

False positive rate: 5% False positive rate: 10%
Risk of sPTB under 34 weeks1:
Risk of sPTB under 37 weeks1:
Risk adjusted by LUS2:
Risk of sPTB under 34 weeks (Detection rate: 53%)2:
Risk of sPTB under 37 weeks (Detection rate: 33%)2:


1. Farràs Llobet, A. et al. Prospective evaluation of the uterocervical angle as a predictor of spontaneous preterm birth. Acta Obstet. Gynecol. Scand. 99, 1511–1518 (2020).

2. Farràs, A. et al. Adjusting cervical length and uterocervical angle by lower uterine segment thickness may improve preterm birth screening. 19th World Congress in Fetal Medicine. Oral Abstract. Crete, 2022.

This is a research-only calculator. This tool is not validated for clinical practice. None of the parties involved in the development of this software will be responsible of the consequences of possible errors and / or malfunctions of it; nor of the consequences derived from its use. Every result must be verified by a trained healthcare professional.