In the world of horse racing, most fans are familiar with watching top-class mares and fillies take on their rivals.

But what may come as a surprise is that some of them may be racing while pregnant. It’s something that not too many racing fans know about, especially casual fans of the sport.

Yes, it is both possible and legal for fillies and mares to race in early pregnancy, and in some cases, it can even be beneficial for performance.

How Long Can Fillies & Mares Race into Pregnancy?

Mares typically carry a foal for around 11 months (approximately 340 days), but racing authorities generally allow them to compete for up to 120 days (around 4 months) into pregnancy.

After that point, most jurisdictions around the world, such as the British Horse Racing Authority in the UK, will prohibit further races for the welfare of the mare and the developing foal.

By that 120-day mark, the fetus is still relatively small and protected, which means the physical stress of racing is not harmful during that early window.

Of course, not all horses are the same, so this is looked at case by case by trainers and vets, to ensure no issues for any of the pregnant runners.

This includes passing pre-race checks, which are standard across the board for all runners, but would flag any issues for pregnant runners, showing they were not able to race.

Why Race a Pregnant Mare?

One reason a mare might race while pregnant is simply down to timing.

Breeding is highly seasonal, especially in the Northern Hemisphere, with most breeders aiming for foals to be born in early spring. This means many mares are covered (bred) early in the year, often while they’re still in training or actively racing, in particular for National Hunt runners.

Some trainers and breeders believe a mare can actually benefit from early pregnancy, due to the hormonal changes that occur.

In particular, higher levels of progesterone (a hormone linked to pregnancy) can have a calming effect and may even help with focus or temperament during races.

This is something that can really interest punters if they know about the situation. Seeing a horse improve out of nowhere can often be frustrating if you’ve backed another. But if you know a horse is pregnant, then at least you have an explanation and reasoning.

There’s also the commercial angle, if we’re being honest. A high-performing pregnant mare may boost her value as a broodmare, especially if she wins a major race while in foal to a well-regarded stallion.

With so many runners retiring from racing for breeding purposes, the financial aspect does have to be taken into consideration.

Pros and Cons of Running While Pregnant

Pros:

• Hormonal calmness can aid performance.
• Opportunity to enhance broodmare value with additional racing success.
• Maintains mares’ fitness while awaiting retirement to stud.

Cons:

• Increased risk of injury or stress to the mare.
• Ethical concerns if pushing a mare to race purely for financial reasons.
• Foal health risks if racing beyond the safe gestation period.

While the idea of a pregnant mare racing might sound surprising to some, it’s a well-regulated and relatively common occurrence in the early stages.

From a punter’s perspective, it would be good to see more information available here, as there can definitely be assistance with racing for those who are pregnant.

If you’re looking to find out more about racing mares, then this topic is certainly one to look into. It’s also something for punters to look at and use to their advantage if they know about a horse that’s running while pregnant and potentially putting up a better-than-expected performance.