Administration of ethiodized poppy seed oil-based contrast agent into the uterus enhances fertilization rate in mice inseminated with low sperm numbers

Sep 29, 2026

Uploaded by Margaret

Study question asks whether administering an oil-based iodinated contrast medium (OSCM) into the mouse uterus improves fertility, paralleling effects seen in women after hysterosalpingography (HSG). In mice inseminated with low sperm numbers, prior intrauterine OSCM increased fertilization and birth rates compared with PBS controls. High-sperm insemination showed no improvement, suggesting benefit emerges under suboptimal fertility conditions. The work uses in vitro embryo development and delivery outcomes while noting heterogeneity limits compared with clinical studies.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages9

Reading Time23 min

AccessFree to download

Abstract

Study question and summary answer

Study design, size, and duration

Participants, materials, and methods

Main results and role of chance

Limitations and reasons for caution

Human Reproduction, 2026, 41(1), 69–77 [https://doi.org/10.1093/humrep/deaf204](https://doi.org/10.1093/humrep/deaf204) Advance Access Publication Date: November 3, 2025 Original Article Reproductive biology Administration of ethiodized poppy seed oil-based contrast agent into the uterus enhances fertilization rate in mice inseminated with low sperm numbers Edgar Del Llano 1, Marlene Rasschaert 2, Christophe Arnoult 1, Philippe Robert2, Pierre F. Ray 1,3, 􀀃 , and Corinne Loeuillet1 1Team Genetics Epigenetics and Therapies of Infertility (GETI), Institute for Advanced Biosciences, INSERM U 1209, CNRS UMR 5309, University Grenoble Alpes, Grenoble, France 2Research and Innovation Department, Guerbet, Roissy CdG, France 3UM GI-DPI, CHU Grenoble Alpes, Grenoble, France 􀀃 Correspondence address. University Grenoble Alpes and Centre Hospitalier Universitaire Grenoble Alpes, 9 Bd de la Chantourne, 38700 La Tronche, France. Tel:þ33-(0)[4-76-76-55-73. E-mail: pray@chu-grenoble.fr](4-76-76-55-73. E-mail: pray@chu-grenoble.fr) https://orcid.org/0000-0003-1544-7449 ABSTRACT STUDY QUESTION: Does the administration of an oil-based iodinated contrast medium (OSCM) in the mouse uterus have a positive effect on fertility similarly to what is observed in women following hysterosalpingography (HSG)? SUMMARY ANSWER: Following IUI of a small number of sperm (mimicking oligozoospermia), fertilization and birth rates were improved in female mice who had previously received an intrauterine administration of an OSCM confirming a pro-fertility effect. WHAT IS KNOWN ALREADY: HSG is a common diagnostic procedure used in infertile or subfertile women, primarily to assess thepatency of fallopian tubes. It consists in injecting an iodinated contrast medium into the uterus to enable the imaging of the female reproductive tract by radiography. In the absence of obstruction, the contrast medium fills the uterus and transits through the fallopian tubes before overflowing in the peritoneal cavity. Several studies reported that in the few months following HSG, women injected with an OSCM (ethyl esters of iodinated fatty acids of poppy seed oil) had an enhanced pregnancy rate (either spontaneous or following IUI) compared to those administered with a water-based contrast medium. This suggests that OSCM administration in the female reproductive tract could improve fertility. However, the physiological mechanisms underlying this potential effect remain unknown. STUDY DESIGN, SIZE, DURATION: OSCM or PBS (phosphate buffered saline, control) were administered into the uteri ofB6D2 female mice (5–9 weeks old, total n ¼ 73) . Two weeks later, intrauterine insemination was performed with mouse epididymis sperm from B6D2 male mice (8–16 weeks old) . Females were euthanized and fertilized oocytes collected and incubated for 4 days up to the blastocyst stage (n ¼ 52). Alternatively, females were left until delivery (n ¼ 21) . PARTICIPANTS/MATERIALS, SETTING, METHODS: Female nulliparous mice were administered either with PBS or OSCM directly into the uterus. After 2 weeks, females were inseminated with a controlled number of sperm. The resulting fertilized/unfertilized oocytes were collected and counted the following day to calculate the fertilization rates and then further incubated in vitro to follow the development to the blastocyst stage. In addition, females were mated with vasectomized males to allow implantation, subsequent pregnancy and birth. MAIN RESULTS AND THE ROLE OF CHANCE: First, females were inseminated with a high number of sperm (5 × 10e5 spermatozoa) . Comparable fertilization rates (67.0 ± 5.4% and 60.0 ± 8.0%, P >0.05) were observed from oocytes originating from OSCM and PBSadministered mice, respectively. This showed that when inseminating with a high number of sperm, uterine OSCM administration had no deleterious effect but did not improve fertilization. We postulated that the potential beneficial effect of OSCM administratio

FAQs

What was the study question about OSCM administration in mice?

Whether administering an oil-based iodinated contrast medium into the mouse uterus improves fertility, similarly to effects observed in women after hysterosalpingography.

How did OSCM affect fertilization when insemination used a high sperm number?

Comparable fertilization rates were observed between OSCM- and PBS-treated mice, indicating no improvement under optimal conditions.

What changes were seen under low sperm numbers (oligozoospermia model)?

With a suboptimal sperm number, fertilization rate increased significantly in OSCM-treated mice versus controls, and treated females produced more pups.

Sep 29, 2026

Uploaded by Margaret