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Does a cat have to be in heat to get pregnant?

Cats are prolific breeders. You may have a pregnant cat without ever realizing she was in heat. This raises the question, do cats have to be in heat to get pregnant? 

Does a cat have to be in heat to get pregnant?

Did your cat get pregnant, seemingly without going into heat? What happened? Put simply, no, a cat can’t get pregnant without going into heat. However, it can be easy to miss the signs your cat is in heat. 

When Cats Go Into Heat

Cats have many heat cycles throughout the year. Most cats begin a heat cycle every 14 to 21 days during breeding season. It’s easy to see how you could miss the signs of your cat being in heat. You may also think she had just come out of heat, so you don’t have to worry for awhile, only to realize she is pregnant. 

A cat’s heat cycle is influenced by temperature and the length of days. If the weather is warm and the days are long, she will go into heat every 14-21 days. 

When the weather is cold and the days or short, she will have a period of time without going into heat. However, cats that spend most of their time indoors or those who live in tropical locations can go into heat all year long. 

Cat Heat Cycle

The entire heat cycle of a cat can last from 1-6 weeks, with 3 weeks being the average. This means she will come into heat approximately every 3 weeks or 21 days. 

Proestrus signals the beginning of the heat cycle. It lasts 1-2 days. During this time, the body prepares for estrus. Estrus is what we generally consider being in heat. This is the time when the cat can get pregnant, and when you’ll notice the signs of heat. 

If she isn’t bred, she won’t ovulate. More on that soon. In this case, she will enter interestrus. This stage lasts between 13-18 days. After this, the cycle restarts with proestrus. 

If she is bred, she enters metestrus or diestrus. This typically lasts for 30-40 days if she isn’t pregnant. If she is pregnant, the estrus cycle will begin again after she has her kittens. 

At the end of breeding season, she will enter anestrus. This means that the cycle is essentially paused. When the conditions are right and breeding season begins again, she will enter proestrus again, repeating the cycle. 

Can You Tell When a Cat is in Heat? 

There are signs of a cat in heat, but they can be hard to spot. One reason for this is because cats do not bleed as much as dogs do. Cats are also fastidious groomers, so they tend to quickly lick away any blood or discharge. 

Most of the signs of a cat in heat are behavioral. Because cats can go into heat so often, it can be difficult to notice these as behavioral changes. If your cat is in heat often, it can easily seem like part of their normal behavior. 

Signs Your Cat is In Heat

Cats tend to become more affectionate when they are in heat. If you notice your cat follows you around or is constantly in your lap, she may be in heat. They will also rub their body against you, and other objects. 

They will become more vocal. She will “call” for a mate. This can sound like yowling, and she may seem as if she is in pain. She does this to attract males to her. This is the sign most cat owners have the biggest issue with, because their calling can seem never ending. 

She may also assume the mating position. She will lower the front of her body, and stick her butt in the air. Her tail will be raised and to the side. 

A tell-tale sign is a desire to be outside or to roam. Essentially, she wants to go find a mate. It’s her biological drive to mate, and some females will seem desperate to go outside. She may scratch or meow at the doors and windows, or try to slip past you when the door opens. 

Female cats will also spray when in heat. Similar to a male, they will pee on vertical objects. This is to leave her scent and signal her readiness to mate. 

Excessive grooming is also common. Cats are very clean animals, and any discharge will likely be quickly cleaned. They may also groom more often as a way to calm their restlessness and anxiety. 

Do cats get pregnant easily?

Yes, cats are fertile animals. In fact, a single cat can have four litters a year, with 1 to 12 kittens in each litter, with the average cat having 5 kittens per litter. That adds up to 20 kittens in a single year. 

Induced Ovulation

The good news is a cat can’t get pregnant the first time they mate. The bad news is a cat can mate 10-20 times in a single day! It only takes cats a few minutes to complete mating, so it’s easy to see how they could mate several times within a short amount of time. 

Cats are induced ovulators. This means that when they mate, this stimulates the release of an egg. Humans ovulate with each period, and can get pregnant when the egg is in the uterus. 

Most cats will need to mate 3-4 times to release an egg. Once the egg is released, she can get pregnant. Cats will typically mate with different males over a period of 4-6 days once the egg has been released. 

If she doesn’t mate, an egg isn’t released. However, the next heat cycle will come quickly, within 12-21 days after the current cycle ends. 

Indiscriminate Breeders

Cats are indiscriminate breeders. Basically, when your cat is in heat, she will mate with any and all available males. They will also mate with family members, including sons and fathers. 

At what age can a cat get pregnant?

A cat can get pregnant as soon as she has a heat cycle. This can occur anywhere between 4-12 months of age, with 6 months being the most common age. 

Breed plays a role in when cats reach sexual maturity. Siamese cats are early bloomers, and can have their first heat at 4 months of age. Persians on the other hand, reach maturity at about 1 year old. 

Seasonality also plays a role. If your cat reaches the age of maturity out of breeding season, they won’t have their first heat until they reach breeding season. 

If she is able to have a heat cycle at 6 months old, but it’s 2 months till breeding season, she will have a heat at 8 months of age. 

When do cats go into heat?

It’s important to know when your cat will likely go into heat. If you want to prevent pregnancy, it’s essential to keep an eye out for heat cycles. 

First Heat

Cats reach sexual maturity early in life. Six months of age is typical, but they can have their first heat between 4-10 months old. 

Seasonal Heat

You can expect your cat to go into heat about every 3 weeks during breeding season. Temperature plays a role in breeding season, but light has the most impact. If there are 14-16 hours of daylight, your cat will have heat cycles. In the Northern Hemisphere, breeding season lasts from January to October. 

It’s important to note that your cat won’t distinguish between natural and artificial light when it comes to breeding. If they are exposed to 14-16 hours of indoor light each day, they will likely have heat cycles. 

Do Cats Stop Going Into Heat?

Cats do not experience menopause the way humans do. Instead, they continue to have heat cycles for their entire lives. In fact, the oldest known kitty to give birth was aptly named kitty. She gave birth to two kittens at 30 years old. 

While cats can conceive at any age once they reach sexual maturity, they are the most fertile from 2-8. As they move into old age, they can still get pregnant but the chances diminish as they age. 

How long are cats in heat for?

The estrus cycle itself lasts for 6 days on average. They can get pregnant at any time during the estrus stage. They can have multiple heat cycles each year. It can seem like your cat is permanently in heat because of the short time between heat cycles. 

What are the signs of a pregnant cat?

It can be difficult to know if a cat is pregnant in the early weeks. However, if you know the signs, you should be able to determine if your cat is pregnant. 

Length of Cat Pregnancy

Cats gestation period ranges from 63-68 days. You can expect them to be pregnant for about 9 weeks before birthing their kittens. Most signs of pregnancy will begin around 3 weeks after conception. 

Increased Appetite and Weight Gain

Your cat is now eating for their kittens as well as themselves. It takes extra calories to grow kittens.

You can also expect her to gain between 2-4 pounds throughout the pregnancy. This may seem like a small change, but the average cat is around 10 pounds. If a 10 pound cat gains 4 pounds, this is a 40% weight gain. 


The hormonal changes of pregnancy can cause your cat to experience vomiting or nausea, which is commonly referred to as morning sickness in humans. 

She may also eat less during periods of morning sickness. However, she should quickly recover and begin eating more. If she has morning sickness or vomiting frequently or has a sharp decrease in appetite, you’ll need to contact your vet. 

Enlarged Abdomen

Of course, those growing kittens will take up room in your kitty’s belly. Expect her stomach to begin to swell and grow throughout the pregnancy. This will become more evident during the later stages of pregnancy. 

No Heat Cycles

Cats will typically stop having heat cycles after they become pregnant. However, it is possible for your cat to have one heat cycle after they get pregnant, so a heat cycle isn’t a guarantee your cat isn’t pregnant. 


If your cat is pregnant, her nipples will turn pink and get bigger. Close to delivery, they may begin to swell with milk. 

More Affectionate

Most cats are more affectionate during pregnancy. This may be one of the first signs you notice. If your normally independent cat suddenly becomes clingy and needy, there’s a chance she’s pregnant. 

Increase in Sleep

Cats will also sleep more when pregnant. Growing kittens requires a lot of energy, and your kitty will need plenty of rest during her pregnancy. If you notice her having more “cat naps”, check for other signs of pregnancy. 

Veterinary Pregnancy Confirmation

If you think your cat is pregnant, you will want to know for sure. The best way to confirm your kitty’s pregnancy is with your vet. 

Your vet can check for kittens by feeling your cat’s stomach. They will be able to feel the kittens at about the 17th-25th day of pregnancy. They can also make a guess as to how many kittens she has, but this isn’t always 100% accurate. 

To determine if your cat is pregnant early on, an ultrasound is the best option. It works similarly to an ultrasound in humans. It allows your vet to see into your cat’s abdomen. This is effective during the second week of pregnancy. 

When your cat is further along in her pregnancy, an x-ray can be performed. This is effective at 42 days of pregnancy, because the skulls of the kittens will be visible on the x-ray at this time. It’s the best way to know for sure how many kittens you are expecting.