Ultrasonographic Change in Uterocervical Angle is not a Risk Factor for Preterm Birth in Women with a Short Cervix
To determine if change in uterocervical angle (UCA) is associated with an increased rate of preterm birth (less than 37 weeks) for women with a short cervix.Study Design
A retrospective study was performed from January 2013 to March 2016 of singleton pregnancies undergoing universal cervical length screening. The difference between the UCA for the first cervical length ≤ 2.5 cm and last recorded cervical length < 25 weeks was defined as the change in UCA. The primary outcome was the rate of preterm birth at < 37 weeks of gestation.Results
A total of 176 women met the inclusion criteria. There was no difference in the rate of preterm birth at < 34 weeks (23.3 vs. 16.7%, p = 0.27) or at < 37 weeks (34.9 vs. 37.8%, p = 0.69) based on a change in UCA (i.e., decreased/no change or increased UCA). However, women with a final UCA ≥105 degrees had an increased risk of preterm birth at less than 34 weeks (24.2 vs. 6.8%, p = 0.01).Conclusion
A change in UCA was not associated with an increased risk of preterm birth. Instead, a final absolute UCA ≥ 105 degrees measured < 25 weeks was associated with an increased risk of preterm birth at < 34 weeks of gestation for women with a short cervix ≤ 2.5 cm.