A randomized double blinded clinical trial to explore the clinical outcomes of vaginal isonicotinic acid hydrazide (INH) administration six hours prior to T380A intrauterine device insertion in persons delivered only by cesarean delivery.

Objective: To compare insertion pain and ease of insertion in participants with a prior caesarean delivery having copper intrauterine device (IUD) after pretreatment with isonicotinic acid hydrazide (INH) 900 mg vaginally or placebo.

Study Design: From September 2020 to September 2021, we conducted a randomized, double-blind, placebo-controlled experiment at Aswan University Hospital in Egypt with participants who were delivered solely by caesarean delivery and desired copper T380A IUD insertion. The participants were randomly assigned to either vaginal INH or placebo six hours before IUD insertion in a 1:1 ratio. The primary objective of the research was the individuals' self-reported pain during cervical tenaculum placement, sound insertion, IUD insertion, and 5 minutes after the placement, as measured by a 10-cm visual analogue scale (VAS). Our secondary outcomes were ease of insertion, satisfaction, the need for analgesics, and adverse effects. IUD insertion ease was graded from 0 to 10 on a 10-cm VAS scale, with 0 suggesting very easy insertion and 10 denoting extremely difficult insertion.

Results: When compared to the placebo group, the INH group experienced considerably less pain during IUD insertion (2.9±0.85vs.5.11±0.82;p<0.01), lower median ease of insertion score (3(1-4)vs.5(3-6);p<0.01), and better satisfaction (8.17±0.69vs.5.57±0.75). The two groups had comparable side effects.

Conclusions: Vaginal INH administered before IUD insertion reduce the amount of discomfort participants feel throughout the process in individuals who had previously only been delivered via CD. It also has the potential to make insertion easier.

Implications: In participants who were delivered solely by CD before, vaginal INH given prior to IUD placement reduces the amount of discomfort participants experience throughout the procedure. Furthermore, it could increase the ease of insertion.