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Embryofetal Toxicology

Embryofetal studies assess the impact of drugs on the reproductive cycle. Specifically, they evaluate their effects on fertility, pregnancy, and the development of embryos and fetuses. Our protocols are tailored to each test item under investigation.

Core Study Types

Scantox provides three developmental and reproductive toxicology (DART) study types. They adhere to international ICH guidelines (e.g., ICH S5(R3)) for drug safety assessments. 

Segment I: Fertility and early embryonic (FEED) studies

Assess the potential impact of the test item on male and female fertility. We typically use rats, but can also use minipigs.

Segment II: Embryo-fetal development (EFD) studies

Conducted on pregnant females during the critical organogenesis period to understand potential adverse effects on the fetus. We also conduct preliminary embryo-fetal development (pEFD) studies with fewer animals and shorter durations, particularly with minipigs.

Segment III: Pre- and postnatal development (PPD) studies

Monitor offspring from birth to the neonatal phase. It also includes assessing behavioral development.

Choosing the Right Animal Model

Two animal species, a rodent, and a non-rodent, are mandatory for reproductive studies. The choice of the species should align with those used in the broader toxicology program.

  • Rodents: Rats are the most often used species because of their small size, high reproduction rate, and small space requirements.
  • Non-rodents: While rabbits are the primary non-rodent model, minipigs are increasingly employed due to their anatomical and physiological similarities to humans.

Minipig model: A Scantox Speciality

Minipigs are a cornerstone of our studies due to their human-like anatomy, manageable size, breeding ease, and cost-effectiveness. We utilize minipigs across various studies, including reproductive toxicology, safety pharmacology, and general toxicology.

Efficient Operations: Our proximity to and partnership with Ellegard Göttingen minipigs A/S ensures rapid delivery of suitable dams. Animals are estrus synchronized and mated at Scantox, optimizing study timelines and enhancing safety. This approach reduces animal stress, shortens study periods, and facilitates delivering high-quality scientific data and earlier reporting to clients.

Examination Types

Fertility Evaluations

  • Assessment of reproductive organs (placenta, uterus, ovaries, corpora lutea counts, number of implantation sites, live and dead embryos..)
  • Ultrasound scanning to confirm pregnancy

Fetal Evaluations

  • Comprehensive external examination of fetuses to monitor body size and identify any variations or malformations (spine curvature, ears, eyes, toes…).
  • Detailed internal examination of organs like the heart, liver, and vascular system (placement, shape, development).
  • Detailed internal examination of fixed and sectioned heads.
  • Detailed examination of skeletal variations or malformations (Alizarin staining).

Sampling and Bioanalysis

  • Collection of fetal blood and amniotic fluid to confirm exposure to test items.
  • Advanced bioanalytical testing possibility in Gothenburg.

Why Choose Scantox?

  • Decades of Experience: Conducting embryofetal development studies since 1995. Specialized experience across various animal models and species.
  • Global Leader in Minipig Repro Studies: One of only two sites worldwide that conduct reproductive studies in minipigs.
  • Comprehensive In-House Capabilities and Animal Welfare: Maintain control over all study processes, from breeding to evaluations, while prioritizing the physical and psychological well-being of the animals. Enhances study reliability and efficiency
  • Extensive Historical Database: This database includes a substantial historical background on adverse findings in minipig fetuses. Such large background data collection is crucial for accurately assessing whether findings are test item-related or normal variations.


The embryofetal toxicology team is led by one of our Senior Study Directors, who has more than 15 years of experience at our Scantox site in Ejby. Our DART team comprises highly skilled technicians experienced in complex procedures and skeletal assessments. With over 20 years of experience, we have conducted extensive reproductive studies on various rodent and non-rodent animal species. Specifically, we have managed more than 28 studies involving minipigs with over 13 different test items. This extensive experience ensures precise and reliable results for your projects.


The incidence of congenital malformations and variations in Göttingen minipigs

S. Ellemann-Laursen, E. Marsden, B. Peter, N. Downes, D. Coulby and A.B. Grossi, Reproductive Toxicology, 2016, 64 (2016), 162-168