This study finds premedication Hyoscine-N-butylbromide before hysterosalpingography have a potential effect for diagnosis of proximal tubal obstruction in infertile women. The investigators did a double-blind, randomized placebo-controlled trial

Infertility is a common gynecologic problem in reproductive medicine. The causes of female infertile can divided into ovulatory dysfunction, tubal and pelvic pathology, unexplained infertility and unusual problems. About 30-35% of case of infertility are caused by the tubal factor and tubal disease is an important cause of infertility and should be specifically excluded(1). Methods for evaluation of the fallopian tube pathology include the Hysterosalpingography(HSG), Saline infusion sonography(SIS) and Laparoscopy with chromopertubation etc(2-3).

Laparoscopy with chromopertubation is considered the definitive test for evaluating tubal disease and allows for the detection of other intraabdominal causes of infertility. However, laparoscopy is expensive, time consuming, limited in some centers, and unpleasant for the patient. More importantly many patients have anesthetic and surgical complications that require hospital admission(4). Therefore, HSG has been most commonly used for routine screening in infertility for evaluation of tubal patency. It is a simple, noninvasive and inexpensive technique. HSG is the standard first-line test to evaluate tubal patency(5-7).

HSG is an X-ray procedure that is used to view the inside of the uterus and fallopian tubes. HSG for investigating tubal patency has moderate sensitivity 65% but excellent specificity 83% in the infertile population. The PPV and NPV of HSG are 38% and 94%, respectively(8-9). However, it can have a false positive diagnosis if the HSG indicates occlusion, there may be a good chance 60% that the tubes are actually patent, and if the HSG demonstrates patency there is a little chance 5% that the tubes are occluded(10). There are several factors leading to a false diagnosis of tubal occlusion by using HSG. The most common factor cited is a cornual spasm(11), there could simply be a resistance difference between the two tubes(12) and the other factor are an existing of mucous plug at proximal part of the fallopian tube(13).

Diagnostic laparoscope performed after HSG showed a decrease in the rate of diagnoses of initial tubal occlusion by 40-60%(14-16). There are studies about repeat HSG 1 month later in patients whom HSG showed proximal tubal blockage, showed tubal patency about 60%(17). And there are many studies about administration of an antispasmodic or analgesic drug to distinguish tubal spasm from tubal occlusion during HSG. Such as Glucagon, Hyoscine butylbromide, ASA, Terbutaline, Diazepam, Fenoterol and Mitamizole etc(18-21). There is only one prospective study about hyoscine butylbromide use after tubal occlusion occur during HSG, showed that appears to be safe and effective drug to relieve proximal tubal obstruction by 80%(22).

Hyoscine-N-butylbromide(Buscopan®), an antispasmodic drug commonly used for relief of smooth muscle spasms and can use to relieve genito-urinary spasm. Hyoscine exerts a spasmolytic action, peripheral anticholinergic effects result from a ganglion-blocking action within the visceral wall as well as from anti-muscarinic activity, could decrease pain during uterine cramping. And about relief tubal obstruction in HSG procedure, no previous studies investigate compared its efficacy in randomized double-blind controlled trial. And there are inexpensive, safe with minimal side effects, then there are studies reported hyoscine can relieve dysmenorrhea too(23-24).

In Thailand, reported that one of the most common causes of female infertility is tubal pathology which accounted for 27% of the cases(25). And at Infertile clinic of Songklanagarind Hospital, mostly use HSG for standard first-line to evaluate tubal patency. We hypothesized that Hyoscine-N-butylbromide use before HSG can relieve the tubal occlusion that not true occlusion. It is possible to decrease the false positive rate of diagnosis of tubal occlusion cause from cornual spasm. So it can apply to use to decrease the necessity of laparoscopy with chromopertubation for definitive test tubal occlusion or repeated. And it will also reduce the medical cost of further more expensive investigation and medical complication.

Inclusion Criteria:

• The infertile women who indicated for investigation hysterosalpingography were enrolled.

Exclusion Criteria:

1. Known sensitivity to Hyoscine or contrast media
2. Genital tract infection
3. Suspected pregnancy
4. Abnormal uterine bleeding