One of the most important applications for ultrasonography lies in the ability to determine the sex of the foetus prior to birth. From just 20 weeks of gestation during human pregnancy (and sometimes even earlier) ultrasound imaging can reveal whether the baby is a boy or a girl, thus allowing the expectant parents to plan accordingly. In addition, veterinary ultrasound can also be a useful tool to help detect whether the foetus is male or female. Vet Image Solutions stock a number of veterinary ultrasound machines that are suitable for use in foetal sexing. However, why might it be useful to know the sex of the impending offspring, and when can you expect to find out if you should be ‘in the pink’, or ‘feeling blue’ (sorry, I couldn’t resist!)?

In human pregnancy, the expectant parents may wish to find out the sex of their baby in order to help them suitably decorate the nursery, to ensure that appropriate baby clothes are bought or to give the parents a ‘head start’ in choosing a baby name (or perhaps the parents just don’t wish to wait nine months to find out!). Although these issues may not be relevant during animal pregnancies, it is still important that foetal sexing is carried out. Firstly, the animal may be used primarily for breeding and a specific sex is required by the eventual owner. Secondly, in cattle, the sex of a foetus can impact whether the eventual offspring becomes used for dairy or beef purposes, which may in turn have financial implications for the breeder/farmer. Thirdly, foetal sexing may allow the breeder to detect the probability of the offspring carrying any genetic diseases it may be predisposed to in advance of the birth. It should be noted that there are many other reasons why it may be desirable to find out the sex of an animal foetus that have not been listed here.

Veterinary ultrasound can be used to sex a foetus in horses between days 120 and 210 of gestation, and this can be done by ultrasound imaging through both the abdominal or pelvic wall – transabdominal and transrectal ultrasonography respectively (Bucca, S 2005). Foetal sexing in cattle by ultrasound imaging has been reported to be more reliable from day 55 of gestation (Quintela LA, 2011 and 2012). Moreover, the importance the time of ultrasound analysis plays in sexing during gestation on the reliability of the final result was also demonstrated (Quintela LA, 2011). In goats, ultrasound imaging can be used to reveal the sex of the fetus from day 50 of gestation (from day 55 of gestation in instances of natural mating and from day 60 of gestation whereby embryos were either fresh or cryopreserved) using transrectal ultrasound imaging (Neto, LM et al. 2010). It should be noted that all these animals have different gestation periods, and so a direct comparison of when foetal sexing can be carried out during gestation should not be attempted!

Veterinary ultrasound clearly plays a critical role in foetal sexing for a variety of animal species (including many not mentioned in this article). Increased availability of novel ultrasound technology is making it easier for the ultrasound practitioner to carry out fetal sexing with greater certainty. For any queries relating to foetal sexing and which is the best ultrasound machine to use, please do not hesitate to contact us.