A Study on the Identification of High-Risk Factors and the Establishment of a Prediction Model for Uterine Rupture in an Unscarred Uterus During Pregnancy.

OBJECTIVE

The diagnosis of uterine rupture was often delayed or misdiagnosed, leading to maternal morbidity and fetal mortality. The current study was performed to retrospectively identify high-risk factors of uterine rupture in an unscarred uterus (USU), and to establish a model to predict uterine rupture in USU during pregnancy.

METHODS

This was a retrospective multi-center study including five regional medical centers from the inception of each medical center to December 31 2021. Out of 547 325 deliveries, 28 patients with USU who had a uterine rupture during pregnancy were recruited. The following clinical characteristics were collected and analyzed: 1) general clinical characteristics; 2) clinical manifestations; 3) high-risk factors; 4) therapeutic strategies; 5) prognosis of mothers and infants.

RESULTS

In patients with a number of gravidities ≥2, the number of artificial abortions, the number of parities, and the amount of intraoperative blood loss were significantly increased (P = .002, .029, and .023). In patients with a previous history of artificial abortion, the number of parities, the probability of hysterectomy, and the incidence of intraoperative blood loss (>1000ml) were significantly increased (P < .001, .030 and .040, respectively). Additionally, multiparous patients had advanced maternal age, an increased number of gravidities, and a higher incidence of vaginal bleeding symptoms with significant differences (P = .042, .001, and .031). Based on the above results, we further developed a prediction model of uterine rupture in an unscarred uterus using Logistic binary regression analysis and the formula was as follows: Logit (P) = -9.112 + (-0.199) × maternal age + 0.374 × gestational age + 1.720 × parity + (-1.162) × number of artificial abortions.

CONCLUSION

The number of gravidities ≥2, previous history of artificial abortion and multipara were associated with adverse outcomes in patients of uterine rupture in USU. A mathematical prediction formula was developed based on the parameters of maternal age, gestational age, number of parities, and number of artificial abortions. The risk of uterine rupture in USU can be predicted with two steps using formula I and formula II developed by us.