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Published on: August 2, 2017
Uterine artery impedance during the first eight postpartum weeks
L Guedes-Martins1, A R Gaio2, J Saraiva3
11] Department of Experimental Biology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal [2] IBMC-Instituto de Biologia Molecular e Celular, 4150-180 Porto, Portugal [3] Hospital Centre of Porto EPE, Department of Women and Reproductive Medicine, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal.
This study established postpartum reference ranges for uterine artery (UtA) pulsatility (PI) and resistance (RI) indices. Findings show increasing uterine impedance in the first 8 weeks postpartum, with multiparity influencing the rate of change.
Area of Science:
- Obstetrics and Gynecology
- Vascular Imaging
- Reproductive Medicine
Background:
- Postpartum uterine artery (UtA) impedance assessment is crucial for monitoring recovery.
- Establishing normative reference ranges for UtA pulsatility (PI) and resistance (RI) indices postpartum is essential for clinical interpretation.
- Previous studies have limited data on UtA impedance changes during the early postpartum period.
Purpose of the Study:
- To construct reference ranges for uterine artery (UtA) mean pulsatility (PI) and resistance (RI) indices from 1 to 8 weeks postpartum.
- To analyze the influence of parity on postpartum UtA impedance.
- To document the prevalence of protodiastolic notching in the uterine arteries during the early postpartum period.
Main Methods:
- A prospective, cross-sectional, observational study involving 320 healthy women from 1 to 8 weeks postpartum.
- Transvaginal color and pulsed Doppler imaging of uterine arteries (UtAs) were performed.
- Mean UtA PI and RI values, and presence of bilateral protodiastolic notch were recorded; reference percentile curves were derived using regression models.
Main Results:
- Uterine impedance (UtA-PI and UtA-RI) progressively increased from 1 to 8 weeks postpartum.
- Lower impedance was observed at week 1 in multiparous women compared to primiparous women.
- The prevalence of protodiastolic notching increased significantly from 22.5% at week 1 to 95.0% at week 8.
Conclusions:
- This study provides novel average uterine artery PI and RI reference charts for weeks 1 through 8 postpartum.
- Postpartum uterine impedance shows a consistent increase, with multiparity affecting the rate of increase but not the overall trend.
- The findings offer valuable data for assessing normal postpartum uterine vascular recovery.
