Is My Mouse Pregnant? High-Frequency Ultrasound Assessment
March 18th, 2021
High-resolution ultrasound can help streamline experiments requiring timed-pregnant mice by determining the state of pregnancy, gestational age, and pregnancy losses. Presented here is a protocol to illustrate methods to assess mouse pregnancies as well as potential pitfalls (image artifacts) that may mimic pregnancy.
High resolution ultrasound can help streamline experiments requiring timed pregnant mice by determining the state of pregnancy, gestational age, and pregnancy losses. This protocol demonstrates how to assess mouse pregnancies and identify potential image artifacts that may mimic pregnancy. To begin, identify the bladder on the screen.
Scanning caudally from the bladder, identify the vagina. When the ultrasound transducer is positioned midline and low on the abdomen, the bladder and vagina are visible. Then scanning slowly and smoothly in a cranial direction, identify the bifurcation of the vagina into the left and right uterine horns.
Survey the left and right uterine horns. Up to mid-gestation, the mouse embryos will be positioned along the right and left peripheries. As they grow, the more distal portions of the uterus and their corresponding embryos will turn outwards and dorsally.
This protocol is especially useful when breeding genetically engineered mice. Typically, heterozygous with heterozygous crosses to yield homozygous offspring lead to failure of proper development, causing prenatal lethality. Mouse embryos at various stages of development are shown here.
Early stage mouse embryos, dead embryos, or resorbed embryos may resemble other organs in the abdomen or feces in the intestines, while intestinal loops may mimic the non-gravid uterus. Some investigators prefer to use a stage mounted transducer, such as shown in this image, but we prefer the handheld method of scanning, since this allows for fast and efficient imaging throughout the abdomen.
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Overview
This protocol demonstrates the use of high-resolution ultrasound to assess mouse pregnancies, determining the state of pregnancy, gestational age, and potential pregnancy losses. It also highlights methods to identify image artifacts that may mimic pregnancy.
Key Study Components
Area of Science
- Neuroscience
- Biology
- Reproductive Biology
Background
- High-resolution ultrasound is a valuable tool in reproductive studies.
- Accurate assessment of pregnancy is crucial for timed experiments.
- Image artifacts can lead to misinterpretation of ultrasound results.
- Understanding the anatomy of the mouse reproductive system is essential for accurate imaging.
Purpose of Study
- To streamline experiments involving timed-pregnant mice.
- To provide a protocol for assessing mouse pregnancies using ultrasound.
- To identify potential pitfalls in ultrasound imaging.
Methods Used
- Identify the bladder on the ultrasound screen.
- Scan caudally to locate the vagina.
- Position the transducer midline and low on the abdomen.
- Scan cranially to identify the bifurcation of the vagina into uterine horns.
Main Results
- Successful identification of pregnancy status using ultrasound.
- Clear visualization of reproductive anatomy in mice.
- Recognition of image artifacts that may mimic pregnancy.
- Streamlined methodology for future reproductive studies.
Conclusions
- High-resolution ultrasound is effective for assessing mouse pregnancies.
- Proper technique is essential to avoid misinterpretation of results.
- This protocol can enhance the reliability of reproductive research.
