Hysterosalpingo-foam sonography versus hysterosalpingography during fertility work-up: an economic evaluation alongside a randomized controlled trial.

STUDY QUESTION: What are the costs and effects of tubal patency testing by hysterosalpingo-foam sonography (HyFoSy) compared to hysterosalpingography (HSG) in infertile women during the fertility work-up? SUMMARY ANSWER: During the fertility work-up, clinical management based on the test results of HyFoSy leads to slightly lower, though not statistically significant, live birth rates, at lower costs, compared to management based on HSG results. WHAT IS KNOWN ALREADY: Traditionally, tubal patency testing during the fertility work-up is performed by HSG. The FOAM trial, formally a non-inferiority study, showed that management decisions based on the results of HyFoSy resulted in a comparable live birth rate at 12 months compared to HSG (46% versus 47%; difference -1.2%, 95% CI: -3.4% to 1.5%; P = 0.27). Compared to HSG, HyFoSy is associated with significantly less pain, it lacks ionizing radiation and exposure to iodinated contrast medium. Moreover, HyFoSy can be performed by a gynaecologist during a one-stop fertility work-up. To our knowledge, the costs of both strategies have never been compared. STUDY DESIGN, SIZE, DURATION: We performed an economic evaluation alongside the FOAM trial, a randomized multicenter study conducted in the Netherlands. Participating infertile women underwent, both HyFoSy and HSG, in a randomized order. The results of both tests were compared and women with discordant test results were randomly allocated to management based on the results of one of the tests. The follow-up period was twelve months. PARTICIPANTS/MATERIALS, SETTING, METHODS: We studied 1160 infertile women (18-41 years) scheduled for tubal patency testing. The primary outcome was ongoing pregnancy leading to live birth. The economic evaluation compared costs and effects of management based on either test within 12 months. We calculated incremental cost-effectiveness ratios (ICERs): the difference in total costs and chance of live birth. Data were analyzed using the intention to treat principle. MAIN RESULTS AND THE ROLE OF CHANCE: Between May 2015 and January 2019, 1026 of the 1160 women underwent both tubal tests and had data available: 747 women with concordant results (48% live births), 136 with inconclusive results (40% live births), and 143 with discordant results (41% had a live birth after management based on HyFoSy results versus 49% with live birth after management based on HSG results). When comparing the two strategies-management based on HyfoSy results versus HSG results-the estimated chance of live birth was 46% after HyFoSy versus 47% after HSG (difference -1.2%; 95% CI: -3.4% to 1.5%). For the procedures itself, HyFoSy cost €136 and HSG €280. When costs of additional fertility treatments were incorporated, the mean total costs per couple were €3307 for the HyFoSy strategy and €3427 for the HSG strategy (mean difference €-119; 95% CI: €-125 to €-114). So, while HyFoSy led to lower costs per couple, live birth rates were also slightly lower. The ICER was €10 042, meaning that by using HyFoSy instead of HSG we would save €10 042 per each additional live birth lost. LIMITATIONS, REASONS FOR CAUTION: When interpreting the results of this study, it needs to be considered that there was a considerable uncertainty around the ICER, and that the direct fertility enhancing effect of both tubal patency tests was not incorporated as women underwent both tubal patency tests in this study. WIDER IMPLICATION OF THE FINDINGS: Compared to clinical management based on HSG results, management guided by HyFoSy leads to slightly lower live birth rates (though not statistically significant) at lower costs, less pain, without ionizing radiation and iodinated contrast exposure. Further research on the comparison of the direct fertility-enhancing effect of both tubal patency tests is needed. STUDY FUNDING/COMPETING INTEREST(S): FOAM trial was an investigator-initiated study, funded by ZonMw, a Dutch organization for Health Research and Development (project number 837001504). IQ Medical Ventures provided the ExEm®-FOAM kits free of charge. The funders had no role in study design, collection, analysis, and interpretation of the data. K.D. reports travel-and speakers fees from Guerbet and her department received research grants from Guerbet outside the submitted work. H.R.V. received consulting-and travel fee from Ferring. A.M.v.P. reports received consulting fee from DEKRA and fee for an expert meeting from Ferring, both outside the submitted work. C.H.d.K. received travel fee from Merck. F.J.M.B. received a grant from Merck and speakers fee from Besins Healthcare. F.J.M.B. is a member of the advisory board of Merck and Ferring. J.v.D. reported speakers fee from Ferring. J.S. reports a research agreement with Takeda and consultancy for Sanofi on MR of motility outside the submitted work. M.v.W. received a travel grant from Oxford Press in the role of deputy editor for Human Reproduction and participates in a DSMB as independent methodologist in obstetrics studies in which she has no other role. B.W.M. received an investigator grant from NHMRC GNT1176437. B.W.M. reports consultancy for ObsEva, Merck, Guerbet, iGenomix, and Merck KGaA and travel support from Merck KGaA. V.M. received research grants from Guerbet, Merck, and Ferring and travel and speakers fees from Guerbet. The other authors do not report conflicts of interest. TRIAL REGISTRATION NUMBER: International Clinical Trials Registry Platform No. NTR4746.

Can hysterosalpingo-foam sonography replace hysterosalpingography as first-choice tubal patency test? A randomized non-inferiority trial.

STUDY QUESTION: Does hysterosalpingo-foam sonography (HyFoSy) lead to similar pregnancy outcomes, compared with hysterosalpingography (HSG), as first-choice tubal patency test in infertile couples? SUMMARY ANSWER: HyFoSy and HSG produce similar findings in a majority of patients and clinical management based on the results of either HyFoSy or HSG, leads to comparable pregnancy outcomes. HyFoSy is experienced as significantly less painful. WHAT IS KNOWN ALREADY: Traditionally, tubal patency testing during fertility work-up is performed by HSG. HyFoSy is an alternative imaging technique lacking ionizing radiation and iodinated contrast medium exposure which is less expensive than HSG. Globally, there is a shift towards the use of office-based diagnostic methods, such as HyFoSy. STUDY DESIGN, SIZE, DURATION: This multicentre, prospective, comparative study with a randomized design was conducted in 26 hospitals in The Netherlands. Participating women underwent both HyFoSy and HSG in randomized order. In case of discordant results, women were randomly allocated to either a management strategy based on HyFoSy or one based on HSG. PARTICIPANTS/MATERIALS, SETTING, METHODS: We included infertile women between 18 and 41 years old who were scheduled for tubal patency testing during their fertility work-up. Women with anovulatory cycles not responding to ovulation induction, endometriosis, severe male infertility or a known iodine contrast allergy were excluded. The primary outcome for the comparison of the HyFoSy- and HSG-based strategies was ongoing pregnancy leading to live birth within 12 months after inclusion in an intention-to-treat analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Between May 2015 and January 2019, 1026 women underwent HyFoSy and HSG. HyFoSy was inconclusive in 97 of them (9.5%), HSG was inconclusive in 30 (2.9%) and both were inconclusive in 9 (0.9%). In 747 women (73%) conclusive tests results were concordant. Of the 143/1026 (14%) with discordant results, 105 were randomized to clinical management based on the results of either HyFoSy or HSG. In this group, 22 of the 54 women (41%) allocated to management based on HyFoSy and 25 of 51 women (49%) allocated to management based on HSG had an ongoing pregnancy leading to live birth (Difference -8%; 95% CI: -27% to 10%). In total, clinical management based on the results of HyFoSy was estimated to lead to a live birth in 474 of 1026 women (46%) versus 486 of 1026 (47%) for management based on HSG (Difference -1.2%; 95% CI: -3.4% to 1.5%). Given the pre-defined margin of -2%, statistically significant non-inferiority of HyFoSy relative to HSG could not be demonstrated (P = 0.27). The mean pain score for HyFoSy on the 1-10 Visual Analogue Scale (VAS) was 3.1 (SD 2.2) and the mean VAS pain score for HSG was 5.4 (SD 2.5; P for difference < 0.001). LIMITATIONS, REASONS FOR CAUTION: Since all women underwent both tubal patency tests, no conclusions on a direct therapeutic effect of tubal flushing could be drawn. WIDER IMPLICATIONS OF THE FINDINGS: HyFoSy or HSG produce similar tubal pathology findings in a majority of infertile couples and, where they differ, a difference in findings does not lead to substantial difference in pregnancy outcome, while HyFoSy is associated with significantly less pain. STUDY FUNDING/COMPETING INTEREST(S): The FOAM study was an investigator-initiated study funded by ZonMw, The Netherlands organization for Health Research and Development (project number 837001504). ZonMw funded the whole project. IQ Medical Ventures provided the ExEm-foam® kits free of charge. The funders had no role in study design, collection, analysis and interpretation of the data. K.D. reports travel and speaker fees from Guerbet. F.J.M.B. reports personal fees as a member of the external advisory board for Merck Serono, The Netherlands, and a research support grant from Merck Serono, outside the submitted work. C.B.L. reports speakers' fee from Ferring in the past, and his department receives research grants from Ferring, Merck and Guerbet. J.S. reports a research agreement with Takeda on MR of motility outside the submitted work. M.V.W. reports leading The Netherlands Satellite of the Cochrane Gynaecology and Fertility Group. B.W.J.M. is supported by an NHMRC Investigator grant (GNT1176437). B.W.J.M. reports consultancy for Guerbet and research funding from Merck and Guerbet. V.M. reports non-financial support from IQ medicals ventures, during the conduct of the study; grants and personal fees from Guerbet, outside the submitted work. The other authors do not report conflicts of interest. TRIAL REGISTRATION NUMBER: NTR4746/NL4587 (https://www.trialregister.nl). TRIAL REGISTRATION DATE: 19 August 2014. DATE OF FIRST PATIENT'S ENROLMENT: 7 May 2015.

Safety of oil-based contrast medium for hysterosalpingography: a systematic review.

Recent meta-analyses have shown that a hysterosalpingography (HSG) with oil-based contrast increases pregnancy rates in subfertile women. However, the frequency of complications during or after an HSG with oil-based contrast in subfertile women and/or their offspring is still unclear. This systematic review and meta-analysis, without restrictions on language, publication date or study design, was performed to fill this knowledge gap. The results show that the most frequently reported complication was intravasation of contrast, which occurred in 2.7% with the use of oil-based contrast (31 cohort studies and randomized controlled trials [RCT], 95% CI 1.7-3.8, absolute event rate 664/19,339), compared with 2.0% with the use of water-based contrast (8 cohort studies and RCT, 95% CI 1.2-3.0, absolute event rate 18/1006). In the cohort studies and RCT there were 18 women with an oil embolism (18/19,339 HSG), all without serious lasting consequences. Four cases with serious consequences of an oil embolism were described (retinal oil embolism [n = 1] and cerebral complaints [n = 3]); these reports did not describe the use of adequate fluoroscopy guidance during HSG. In conclusion, the most frequently reported complication after an HSG with oil-based contrast is intravasation occurring in 2.7%. In total four cases with serious consequences of oil embolisms in subfertile women were published.

The long-term costs and effects of tubal flushing with oil-based versus water-based contrast during hysterosalpingography.

RESEARCH QUESTION: What are the long-term costs and effects of oil- versus water-based contrast in infertile women undergoing hysterosalpingography (HSG)? DESIGN: This economic evaluation of a long-term follow-up of a multicentre randomized controlled trial involved 1119 infertile women randomized to HSG with oil- (n = 557) or water-based contrast (n = 562) in the Netherlands. RESULTS: In the oil-based contrast group, 39.8% of women needed no other treatment, 34.6% underwent intrauterine insemination (IUI) and 25.6% had IVF/intracytoplasmic sperm injection (ICSI) in the 5 years following HSG. In the water-based contrast group, 35.0% of women had no other treatment, 34.2% had IUI and 30.8% had IVF/ICSI in the 5 years following HSG (P = 0.113). After 5 years of follow-up, HSG using oil-based contrast resulted in equivalent costs (mean cost difference -€144; 95% confidence interval [CI] -€579 to +€290; P = 0.515) for a 5% increase in the cumulative ongoing pregnancy rate compared with HSG using water-based contrast (80% compared with 75%, Relative Risk (RR) 1.07; 95% CI 1.00-1.14). Similarly, HSG with oil-based contrast resulted in equivalent costs (mean cost difference -€50; 95% CI -€576 to +€475; P = 0.850) for a 7.5% increase in the cumulative live birth rate compared with HSG with water-based contrast (74.8% compared with 67.3%, RR 1.11; 95% CI 1.03-1.20), making it the dominant strategy. Scenario analyses suggest that the oil-based contrast medium is the dominant strategy up to a price difference of €300. CONCLUSION: Over a 5-year follow-up, HSG with an oil-based contrast was associated with a 5% increase in ongoing pregnancy rate, a 7.5% increase in live birth rate and similar costs to HSG with water-based contrast.

Iodine contrast prior to or during pregnancy and neonatal thyroid function: a systematic review.

OBJECTIVE: Thyroid dysfunction is a known side effect of iodinated contrast media. There is some evidence to suggest that iodinated contrast media administered to pregnant women may cause thyroid dysfunction not only in themselves but also in their offspring. Here, we systematically evaluated literature on the use of iodinated contrast media prior to or during pregnancy on the offspring's thyroid function. DESIGN: Systematic review of published literature. MATERIALS AND METHODS: Relevant studies were identified by PubMed, EMBASE and The Cochrane Library up to June 5, 2020. All study designs, reporting on the foetal or neonatal thyroid function after exposure to iodinated contrast media prior to or during pregnancy, were included. We undertook random effects meta-analysis and pooled the estimates as proportions with 95% CIs. RESULTS: We identified 402 articles, of which 26 were included. Six studies reported (n = 369) on exposure to iodinated contrast media prior to pregnancy by hysterosalpingography and 20 studies (n = 670) on exposure to these media during pregnancy by amniofetography, urography or CT. There was low to high risk of bias. The proportion of (transient) neonatal thyroid dysfunction was 0.0% (95% CI: 0.0-2.9% based on 3 studies) for hysterosalpingography, 2.25% (95% CI: 0.03-6.55% based on 2 studies) for amniofetography and 0.0% (95% CI: 0.0-0.02% based on 5 studies) for CT. There was a tendency towards an increased risk of thyroid dysfunction with higher amounts of contrast used. CONCLUSIONS: Exposure to iodinated contrast media prior to or during pregnancy may increase the risk of thyroid dysfunction in offspring. We recommend keeping the amount of contrast used as low as possible.

How long does the fertility-enhancing effect of hysterosalpingography with oil-based contrast last?

RESEARCH QUESTION: Does the fertility-enhancing effect of tubal flushing during hysterosalpingography (HSG) with oil-based contrast change over time? DESIGN: This was a secondary analysis of the H2Oil (long-term follow-up) study, a multicentre randomized controlled trial evaluating the effectiveness of oil-based and water-based contrast during HSG. The main outcome was ongoing pregnancy. Cox proportional hazards models for time to ongoing pregnancy were fitted over 3 years of follow-up. RESULTS: Data on 1107 couples were available; 550 couples had oil-based contrast and 557 water-based contrast at HSG. Ongoing pregnancy rates after 3 years were 77% and 71%, respectively. Median follow-up was 9-10 months (5th-95th percentile: <1 to 36). The hazard ratio for ongoing pregnancy for oil versus water over 3 years of follow-up was 1.26 (95% confidence interval [CI] 1.10-1.45). The scaled Schoenfeld residual plots showed a decrease in hazard ratio that was linear with log-transformed time. After including an interaction with log-transformed time, the hazard ratio immediately after HSG was 1.71 (95% CI 1.27-2.31) and reduced to no effect (hazard ratio of 1) at approximately 2 years. There was no evidence for a change in hazard ratio over time in a subgroup of women who experienced pain during HSG. CONCLUSIONS: The hazard ratio for ongoing pregnancy of oil-based versus water-based contrast was 1.71 immediately after HSG, gradually decreasing and plateauing towards a hazard ratio of 1 (indicating no effect) after approximately 2 years. This supports the hypothesis that oil-based contrast might dislodge debris or mucus plugs from the Fallopian tubes, but this has yet to be definitively proved.

Tubal flushing with oil-based or water-based contrast at hysterosalpingography for infertility: long-term reproductive outcomes of a randomized trial.

OBJECTIVE: To determine the impact of oil-based versus water-based contrast on pregnancy and live birth rates ≤5 years after hysterosalpingography (HSG) in infertile women. DESIGN: A 5-year follow-up study of a multicenter randomized trial. SETTING: Hospitals. PATIENT(S): Infertile women with an ovulatory cycle, 18-39 years of age, and having a low risk of tubal pathology. INTERVENTION(S): Use of oil-based versus water-based contrast during HSG. MAIN OUTCOME MEASURE(S): Ongoing pregnancy, live births, time to ongoing pregnancy, second ongoing pregnancy. RESULT(S): A total of 1,119 women were randomly assigned to HSG with oil-based contrast (n = 557) or water-based contrast (n = 562). After 5 years, 444 of 555 women in the oil group (80.0%) and 419 of 559 women in the water group (75.0%) had an ongoing pregnancy (relative risk [RR] 1.07; 95% confidence interval [CI] 1.00-1.14), and 415 of 555 women in the oil group (74.8%) and 376 of 559 women in the water group (67.3%) had live births (RR 1.11; 95% CI 1.03-1.20). In the oil group, 228 pregnancies (41.1%) were conceived naturally versus 194 (34.7%) pregnancies in the water group (RR 1.18; 95% CI 1.02-1.38). The time to ongoing pregnancy was significantly shorter in the oil group versus the water group (10.0 vs. 13.7 months; hazard ratio, 1.25; 95% CI 1.09-1.43). No difference was found in the occurrence of a second ongoing pregnancy. CONCLUSION(S): During a 5-year time frame, ongoing pregnancy and live birth rates are higher after tubal flushing with oil-based contrast during HSG compared with water-based contrast. More pregnancies are naturally conceived and time to ongoing pregnancy is shorter after HSG with oil-based contrast. CLINICAL TRIAL REGISTRATION NUMBER: Netherlands Trial Register (NTR) 3270 and NTR6577(www.trialregister.nl).

Complications after hysterosalpingography with oil- or water-based contrast: results of a nationwide survey.

STUDY QUESTION: What is the incidence of complications after hysterosalpingography (HSG) using oil-based contrast versus water-based contrast? SUMMARY ANSWER: Among 5165 women undergoing HSG, the most frequently reported complication after HSG with oil- and water-based contrast was intravasation of contrast medium (4.8% versus 1.3%, respectively), which was without further consequences, and pulmonary embolization or death did not occur. WHAT IS KNOWN ALREADY: An HSG with oil-based contrast increases pregnancy rates in women with unexplained infertility. However, there have been some concerns regarding complications, including the risks of intravasation of the contrast medium, oil embolism and infection. Here, we present the incidence of complications after HSG with different types of contrast media used in the Netherlands in the year 2017. STUDY DESIGN SIZE DURATION: In January 2018, an electronic survey was sent to all 73 clinics in the Netherlands that perform HSG. The survey consisted of 12 questions addressing the number of HSGs performed in 2017, the amount and type of contrast medium used, the occurrence of post-procedural complications and what their clinical consequences were. Non-responding clinics were sent multiple reminders. PARTICIPANTS/MATERIALS SETTING METHODS: We calculated the incidence of the complications and reported on their clinical consequences. Furthermore, we examined the average amount of contrast used as well as the administration of prophylactic antibiotics. MAIN RESULTS AND THE ROLE OF CHANCE: The response rate was 96% (67/70) (during the study, one site closed and was not included while two clinics no longer performed HSGs). In the 67 clinics, 3289 HSGs with oil-based contrast and 1876 HSGs with water-based contrast were performed in 2017. The median amount of contrast used was 8.0 ml (interquartile range (IQR) 7.0-10.0) for oil-based contrast and 10.0 ml for water-based contrast (IQR 10.0-10.0). Antibiotic prophylaxis was administered in 61% (41/67) of the clinics. Intravasation occurred in 4.8% of the HSGs performed with oil-based contrast and in 1.3% of the HSGs with water-based contrast (relative risk (RR), 3.6; CI, 2.4-5.4). Pulmonary embolism or death was not reported. Pelvic inflammatory disease (PID) occurred in 0.3% of the HSGs performed with oil-based contrast versus 0.4% with water-based contrast. PID occurred in 0.3% of the HSGs in clinics using antibiotic prophylaxis and 0.2% in clinics not using antibiotic prophylaxis. Allergic reactions were reported in one HSG performed with oil-based contrast (0.03%) compared with two HSGs performed with water-based contrast (0.1%). Anaphylactic reactions did not occur. The overall complication rate was 5.1% in the clinics that used oil-based contrast versus 1.8% in the clinics that used water-based contrast (RR, 2.8; CI, 1.9-4.0; P-value, <0.0001). LIMITATIONS REASONS FOR CAUTION: Half of the clinics did not routinely register complications, and the incidence of the complications in their clinic was based on the recall of the clinician. Estimated complication rates in the clinics with and without systematic registration did not significantly differ. The survey asked about the frequency of intravasation but no classification system is being used in daily practice, which may create differences in reporting. There was no standard screening of post-HSG thyroid function for the mother and the foetus. WIDER IMPLICATIONS OF THE FINDINGS: In this nationwide cohort study, the complication rates after HSG were low. Intravasation occurred more frequently with the use of oil-based contrast compared with water-based contrast but did not lead to any problems or symptoms in any of the women. We therefore conclude that safety concerns should not be a reason to deny the use of oil-based contrast in women with unexplained infertility. The data also support that fluoroscopy appears to be an essential safety measure during HSG. STUDY FUNDING/COMPETING INTERESTS: This work was partly funded by Guerbet, France. I.R. reports receiving travel fee for presenting at the Congress of the American Society for Reproductive Medicine 2019 from Guerbet. V.M. reports receiving travel and speaker's fee as well as research grants from Guerbet. K.D. reports receiving travel and speaker's fee from Guerbet. B.W.M. is supported by an National Health and Medical Research Council (NHMRC) Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for ObsEva, Merck KGaA and Guerbet and travel and research grants from Merck KGaA and Guerbet. The other authors do not report conflicts of interest. TRIAL REGISTRATION NUMBER: N19.056.

Tubal flushing with oil- or water-based contrast medium: can we identify markers that indicate treatment benefit?

STUDY QUESTION: Can we identify patient characteristics that distinguish which ovulatory infertile women undergoing hysterosalpingography (HSG) benefit more or less from flushing with oil-based contrast medium compared to water-based contrast medium? SUMMARY ANSWER: In ovulatory infertile women, HSG with oil-based contrast medium resulted in higher 6-month ongoing pregnancy and live birth rates as compared to HSG with water-based contrast medium and this treatment effect was independent of characteristics of the couple. WHAT IS KNOWN ALREADY: We recently showed that in infertile women undergoing HSG, flushing with oil-based contrast medium resulted in more ongoing pregnancies than flushing with water-based contrast medium. STUDY DESIGN SIZE DURATION: We used data from our randomized clinical trial (RCT) in which 1,119 ovulatory infertile women undergoing HSG during fertility work-up were randomized for use of oil-based (N = 557) or water-based (N = 562) contrast medium. PARTICIPANTS/MATERIALS SETTING METHODS: We built logistic regression models to predict ongoing pregnancy and live birth (secondary outcome) as a function of the specific contrast, the specific marker, and marker-by-contrast-interaction. Markers considered were female age, maternal ethnicity, female smoking, body mass index (BMI), duration of infertility, infertility being primary or secondary, sperm quality, and previous appendectomy. MAIN RESULTS AND THE ROLE OF CHANCE: The 6-month ongoing pregnancy rates in the overall population were 39.7% after use of oil-based contrast versus 29.1% after use of water-based contrast medium [relative risk (RR), 1.37; 95% confidence interval (CI), 1.16-1.61; P < 0.001]. Among the studied baseline characteristics, BMI (P = 0.002) and semen volume (P = 0.02) were statistically significant prognosticators. The treatment effect of oil-based contrast was stronger in women with a BMI ≤30 kg/m2 [RR, 1.54; 95% CI, 1.23-1.92; P = 0.002], and in women whose partner had a semen volume >3 ml [RR, 1.77; 95% CI, 1.28-2.46; P = 0.02]. Also, in women who smoked, the treatment effect of flushing with oil was stronger, but this interaction did not reach statistical significance (P = 0.066). We found no positive effect of oil-based contrast in obese women. We found similar but weaker associations for live birth, which was probably due to lower number of events resulting in less power. LIMITATIONS REASONS FOR CAUTION: The RCT was restricted to infertile ovulatory women younger than 39 years of age without endocrinological disorders and at low risk for tubal pathology. Our results should not be generalized to infertile women who do not share these features. WIDER IMPLICATIONS OF THE FINDINGS: All infertile, ovulatory women younger than 39 years with a low risk for tubal pathology will benefit from an HSG with oil-based contrast; therefore, this should be offered to them after fertility work-up. STUDY FUNDING/COMPETING INTERESTS: The original H2Oil RCT was an investigator-initiated study that was funded by the two academic institutions (AMC and VUmc) of the Amsterdam UMC. The study displayed in this paper was funded by an unconditional research grant from Guerbet. B.W.M. is supported by an NHMRC Practitioner Fellowship (GNT1082548). K.D. reports consultancy for Guerbet, during the conduct of the study, and also reports research grants from Guerbet. C.B.L. reports grants from Guerbet, during the conduct of the study, and grants from Ferring, grants from Merck, and personal fees from Ferring, outside the submitted work. P.H. reports grants from Guerbet, during the conduct of the study, and grants from Ferring and Merck, outside the submitted work. V.M. reports receiving travel and speakers fee as well as research grants from Guerbet. B.W.M. reports consultancy for ObsEva, Merck, Merck KGaA, and Guerbet, and research grants from Guerbet and Merck. The other authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER: NTR 3270 www.trialregister.nl. TRIAL REGISTRATION DATE: 1 February 2012. DATE OF FIRST PATIENT'S ENROLMENT: 3 February 2012.

The FOAM study: is Hysterosalpingo foam sonography (HyFoSy) a cost-effective alternative for hysterosalpingography (HSG) in assessing tubal patency in subfertile women? Study protocol for a randomized controlled trial.

BACKGROUND: Tubal pathology is a causative factor in 20% of subfertile couples. Traditionally, tubal testing during fertility work-up is performed by hysterosalpingography (HSG). Hysterosalpingo-foam sonography (HyFoSy) is a new technique that is thought to have comparable accuracy as HSG, while it is less expensive and more patient friendly. HyFoSy would be an acceptable alternative for HSG, provided it has similar effectiveness in terms of patient outcomes. METHODS/DESIGN: We aim to compare the effectiveness and costs of management guided by HyFoSy or by HSG. Consenting women will undergo tubal testing by both HyFoSy and HSG in a randomized order during fertility work-up. The study group will consist of 1163 subfertile women between 18 and 41 years old who are scheduled for tubal patency testing during their fertility work-up. Women with anovulatory cycles not responding to ovulation induction, endometriosis, severe male subfertility or a known contrast (iodine) allergy will be excluded. We anticipate that 7 % (N = 82) of the participants will have discordant test results for HyFoSy and HSG. These participants will be randomly allocated to either a management strategy based on HyFoSy or a management strategy based on HSG, resulting in either a diagnostic laparoscopy with chromopertubation or a strategy that assumes tubal patency (intrauterine insemination or expectant management). The primary outcome is ongoing pregnancy leading to live birth within 12 months after randomization. Secondary outcomes are patient pain scores, time to pregnancy, clinical pregnancy, miscarriage rate, multiple pregnancy rate, preterm birth rate and number of additional treatments. Costs will be estimated by counting resource use and calculating unit prices. DISCUSSION: This trial will compare the effectiveness and costs of HyFoSy versus HSG in assessing tubal patency in subfertile women. TRIAL REGISTRATION: Dutch Trial Register (NTR 4746, http://www.trialregister.nl ). Date of registration: 19 August 2014.