This is a randomized controlled trial evaluating the efficacy of preoperative analgesic medications - Indomethacin (100 mg per rectum) and Paracetamol/Acamol (1,000 mg intravenously) - for pain management during oocyte retrieval in women undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).

Pain during oocyte retrieval is one of the most commonly reported concerns among women undergoing assisted reproductive technology (ART). The procedure involves transvaginal ultrasound-guided aspiration of ovarian follicles, which causes pain through needle puncture of ovarian and surrounding tissues. Adequate analgesia is essential not only for patient comfort but also to minimize procedural stress, reduce the need for deeper sedation, shorten recovery time, and potentially improve treatment outcomes.

Existing analgesic approaches - including paracervical blocks, conscious sedation, and general anesthesia - carry limitations such as hemodynamic risks, prolonged recovery, and increased resource requirements. Randomized controlled trial (RCT) evidence on non-invasive preoperative analgesics for this indication remains limited and methodologically heterogeneous.

This study is a three-arm, randomized, controlled trial comparing two preoperative analgesic regimens against a no-premedication control group in women undergoing oocyte retrieval under standard anesthesia at the IVF Unit, Galilee Medical Centre.

Participants will be randomized to one of three groups:

Group 1: Indomethacin 100 mg per rectum, administered prior to oocyte retrieval Group 2: Paracetamol (Acamol) 1,000 mg intravenously, administered prior to oocyte retrieval Group 3 (Control): No active preoperative analgesic medication

All participants will undergo oocyte retrieval under standard anesthesia protocols. Pain will be assessed using the Numerical Rating Scale (NRS) immediately post-procedure, every 15 minutes for 2 hours, prior to discharge, and again 3 days after the procedure. Patient satisfaction, side effects, need for rescue analgesia, IVF success rates, and cost-effectiveness will also be recorded.

The study adheres to Good Clinical Practice (GCP) guidelines. All participants will provide written informed consent prior to enrollment. The protocol has been reviewed and approved by the relevant institutional ethics committee (Protocol No. 0240-24-NHR)

Inclusion Criteria:

• Women undergoing oocyte retrieval for IVF or ICSI
• Age 18-45 years
• ASA physical status classification I or II
• Willing and able to provide written informed consent

Exclusion Criteria:

• Known allergy or hypersensitivity to Indomethacin, any NSAID, or Paracetamol
• History of gastrointestinal bleeding or peptic ulceration
• Renal impairment (GFR < 30 ml/min/1.73m² or Creatinine > 1.04 mg/dL)
• Hepatic impairment (ALT > 55 U/L, AST > upper limit of normal, ALP > upper limit of normal, Total Bilirubin > 1.2 mg/dL, or Albumin < 3.5 g/dL)
• Participation in another clinical trial that may interfere with the outcomes of this study

Individual participant data sharing has not yet been determined. Decisions regarding IPD sharing will be made following study completion, ethical review, and in accordance with the data protection policies of Galilee Medical Centre and applicable Israeli privacy regulations. Requests for data sharing may be considered on a case-by-case basis.

Participants are blinded to their treatment allocation. All interventions (Indomethacin per rectum, Paracetamol IV, or no medication) are administered after induction of anesthesia, so participants are unaware of the treatment they received. Investigators and clinical staff are not blinded.