This is a prospective cohort study designed to assess intra-abdominal blood volume and hemodynamic status by measuring the diameter of the inferior vena cava (IVC) using 3D and Doppler ultrasound within 24 hours after gynecological surgery. The study will examine the association between these ultrasound findings and postoperative outcomes, including hemoglobin drop, need for blood transfusion, pain, infection, and length of hospitalization. Approximately 250 women undergoing laparotomy, laparoscopy, or vaginal surgery at Holy Family Hospital will be enrolled. The study also aimed to define postoperative normograms for fluid volume and IVC parameters and to evaluate whether ultrasound-guided decision-making could improve postoperative care and reduce unnecessary interventions.

Postoperative intra-abdominal bleeding is a significant contributor to morbidity and, in some cases, mortality following gynecological surgery. Timely recognition of intra-abdominal blood loss is essential for appropriate clinical intervention. In cases where bleeding is into the abdominal cavity, diagnosis is more difficult and may be delayed.

Ultrasound is a non-invasive, rapid, and widely available tool for assessing free intra-abdominal and pelvic fluid. Modern machines allow for 3D volumetric assessment of fluid collections, as well as Doppler-based measurements of the inferior vena cava (IVC) diameter and its collapsibility index-both of which are known to correlate with intravascular volume status and blood loss. Currently, there are limited data establishing normal ranges of intra-abdominal fluid or IVC diameter postoperatively, and little is known about the magnitude of these measurements and clinical outcomes after gynecologic procedures.

This prospective cohort study aims to quantify intra-abdominal fluid and determine IVC diameter and its collapsibility index using advanced ultrasound imaging within 24 hours after surgery. Patients undergoing open, laparoscopic, or vaginal gynecological procedures will be included. The study will explore correlations between ultrasound findings and clinical outcomes such as hemoglobin drop, need for blood transfusion, infection, pain, and length of hospital stay. Additionally, we aim to develop reference normograms for postoperative normal ranges of intraabdominal fluid volume and IVC diameter.

Inclusion Criteria:

• Women aged 18 years and older
• Undergoing gynecological surgery including laparotomy, laparoscopy, and vaginal pelvic surgery
• Able to provide informed consent

Exclusion Criteria:

• Undergoing minor procedures (e.g., dilation and curettage, hysteroscopy, or cervical conization)
• Known preoperative coagulation disorders
• Postoperative admission to the intensive care unit (ICU)
• Clinical indication requiring ultrasound as part of standard postoperative care

Women aged 18 years and older undergoing gynecological surgery (open, laparoscopic, or vaginal) at Holy Family Hospital in Nazareth, Israel.