Academic Appointments

All Publications

  • Transcutaneous electrical nerve stimulation (TENS) for pain control during first-trimester procedural abortion: a blinded randomized controlled trial. Contraception Henkel, A., Cahill, E. P., Chavez, S., Shorter, J. M., Liu, S. M., Amaya, S. I., Kaur, S., Shaw, K. A. 2025: 110955

    Abstract

    To evaluate the efficacy of transcutaneous electrical nerve stimulation (TENS) to manage pain during first-trimester procedural abortion for those not eligible for or otherwise forgoing sedation.This is a double-blinded, block-randomized superiority trial (IRB approved, NCT05320432) comparing TENS (placed posteriorly, T10-L1 and S2-S4) to sham for pain management during first-trimester procedural abortion. We enrolled pregnant people less than 12 weeks gestation, English- or Spanish-speaking at two outpatient clinics not receiving sedation. The primary outcome was self-reported pain by visual analog scale (VAS, 100 mm) with passage of largest cervical dilator. We planned to enroll 70 patients to detect a 15 mm difference in median pain score (80% power, α = 0.05).Between January 2023 and March 2024, we enrolled 70 participants. Baseline demographics were balanced between groups: median (range) gestational duration 6 (5-11) weeks, 35.7% nulliparous. Median (range) reported pain with passage of largest dilator was 44mm (0-88) and 50mm (0-96) in the TENS and sham groups, respectively (p=0.56). We did not find a difference in median pain at any collected time point including placement of tenaculum, paracervical block, aspiration, or recovery. The active TENS group was more likely to say they would recommend this method of pain control to others (94mm vs 73mm, p=0.01). More participants receiving TENS unit correctly identified their group allocation (91.4% vs 63.6%, p<0.001).While we did not demonstrate a difference in pain scores during the procedure, TENS is a non-pharmacologic alternative that may improve patient experience during uterine aspiration.In a blinded randomized trial, the median pain scores reported during first-trimester procedure abortion did not differ between those receiving TENS or sham. However, those randomized to TENS were more likely to say they would recommend this method of pain control. For those with contraindications to IV sedation, improved experience may justify consideration of offering TENS during first-trimester abortion care.

    View details for DOI 10.1016/j.contraception.2025.110955

    View details for PubMedID 40381673

  • Fifty years of BMJ SRH: a US perspective on achievements in sexual and reproductive health. BMJ sexual & reproductive health Amaya, S. I., Blumenthal, P. D. 2025

    View details for DOI 10.1136/bmjsrh-2024-202560

    View details for PubMedID 40139743

  • Rh sensitization in abortion care: where we've been and where we're going. Current opinion in obstetrics & gynecology Amaya, S. I., Cahill, E., Blumenthal, P. D. 2024

    Abstract

    PURPOSE OF REVIEW: The purpose of this review is to summarize the historical context and recent literature that contribute to the debate about preventive strategies for Rhesus (Rh)-alloimmunization in abortion are.RECENT FINDINGS: Recent studies repeatedly demonstrate that the risk of Rh-alloimmunization in first trimester abortion care is very low.SUMMARY: Recent high-quality studies have demonstrated the physiologic presence of fetal red blood cells in maternal circulation even prior to abortion. Thus, establishing the low utility of Rh immunoglobulin prior to abortion before 12 weeks of gestation. There is yet to exist a consensus guideline that balances the desire to prevent a rare devastating outcome and the need to create practical guidelines based on evidence-based risk assessments.

    View details for DOI 10.1097/GCO.0000000000000988

    View details for PubMedID 39361334

  • Intrauterine devices are a safe form of contraception in users with solid organ transplantation: A single-center experience. Transplant infectious disease : an official journal of the Transplantation Society Amaya, S. I., Wolff, S. F., Ross, M., French, V. A. 2023: e14220

    Abstract

    Patients who undergo organ transplantation are advised to use contraception for health optimization, yet limited data exists on safe contraceptive options for this population. This study investigates the infection risk of intrauterine devices (IUDs) in patients who have received a solid organ transplant by evaluating the incidence of pelvic inflammatory disease (PID). We performed a retrospective chart review of subjects with a solid organ transplant who used an IUD between the years of January 2007 to February 2021. We included subjects ages 22-55 years at the time of IUD placement. We abstracted demographic information, transplant type, IUD type, immunosuppressive medications, screening for sexually transmitted infections, and diagnosis of PID. We identified 29 subjects that met the inclusion criteria. Six subjects had a copper IUD (21%) and 23 had a levonorgestrel IUD (79%). The most common organ transplanted was a kidney (n = 10) and liver (n = 10) while five subjects had multiple organs transplanted. Twenty-five (86.2%) subjects took immunosuppressive medications at the time of IUD insertion. Twenty-four (82.8%) patients had their IUD placed after transplantation. The average time of IUD use was 2.5 years. . In our study of IUD use in patients with solid organ transplantation, no patients developed PID. IUDs are a safe contraceptive option for immunosuppressed transplant patients.

    View details for DOI 10.1111/tid.14220

    View details for PubMedID 38160328

  • Management of missing intrauterine device strings and migrated intrauterine devices. Current opinion in obstetrics & gynecology Amaya, S. I., Blumenthal, P. D. 2023

    Abstract

    The purpose of this review is to review the recent literature with respect to the management of missing intrauterine device (IUD) strings. As IUD use has increased over time, it is important to review management options for this uncommon but possible complication.This article will cover stepwise approaches to management of missing IUD strings based on the most recent literature. Initial steps include obtaining history and using in office tools to reveal IUD strings. Subsequent steps focus on imaging guidelines including obtaining transvaginal ultrasound when available. Finally, IUD removal with tools for uterine instrumentation are discussed, focusing on using tools that do not require cervical dilation and allow for grasping of the device.This paper details a stepwise approach to the management of missing IUD strings which, as discussed in the article, may become more frequent given the rise of IUD use in general and postpartum placement in specific.

    View details for DOI 10.1097/GCO.0000000000000911

    View details for PubMedID 37610992

  • Early Pregnancy Assessment Clinics: Expanding Patient-Centered and Equitable Early Pregnancy Care CURRENT OBSTETRICS AND GYNECOLOGY REPORTS Amaya, S., Shorter, J. 2023

    View details for DOI 10.1007/s13669-023-00353-y

    View details for Web of Science ID 000941898100001

  • Words matter: perforation or transmural migration? BMJ sexual & reproductive health Amaya, S. I., Henkel, A., Blumenthal, P. D. 2022

    View details for DOI 10.1136/bmjsrh-2022-201738

    View details for PubMedID 36564157