How long are cats pregnant? The nine weeks, week by week

If your cat has slipped out during a heat and come home with that look about her, the first question is always the same: how long have you got? The answer is shorter than most people expect. A cat's pregnancy, called gestation, lasts around 63 to 65 days, roughly nine weeks. Some go a little shorter, some a little longer, but anything past day 70 needs a vet the same day.

Nine weeks is fast. A human pregnancy gives you nine months to read books and assemble furniture. A cat gives you nine weeks to notice, confirm, re-plan the house and prepare a birthing space. That speed means the window for good decisions is short, so it pays to know what each week should look like.

The short answer

Gestation runs from the day of mating, not from the day you notice anything. Because cats mate several times across a heat, and because a litter can have more than one father, the due date can drift by a few days in either direction. Plan around day 63 to 65 from the last likely mating, and treat day 70 as the hard limit after which a vet check is not optional.

Worth knowing before anything else: an unspayed female can come into heat every two to three weeks from spring to autumn, and can be pregnant from four months old. If the cat in question is a young stray, the calendar may already be further along than anyone realises.

Week by week

The first two weeks are the quiet trap. Nothing shows, nothing changes, and it is entirely possible to book a spay appointment for a cat who is already pregnant. If there is any chance at all, tell the vet; a quick check costs little and spares everyone a surprise.

Confirming it properly

Guessing from a round belly is unreliable: weight gain, worms and fluid can all mimic pregnancy, and a hormonal condition called phantom pregnancy can produce every sign including milk. A vet can usually feel kittens from around day 20, see them on ultrasound from about day 25, and count them on an X-ray after day 45 when the skeletons have formed. Knowing the number matters, because a kitten left behind at birth is an emergency, and you cannot count what you never knew was there.

Feeding a pregnant cat

From about week four, move her onto kitten food. It is denser in calories, protein and calcium, which is exactly what growing kittens demand. Feed small meals more often, because by week six her stomach has serious competition for space. By the final weeks she may need a third more food than usual, delivered in four or five small servings.

Do not overdo it in the first weeks. Fat cats have harder births; the kittens need nutrition, not volume.

Fresh water down at all times, and no supplements unless your vet prescribes them. Too much calcium before birth can cause the very problems people supplement to prevent, including eclampsia, a dangerous drop in blood calcium after delivery.

Setting up the kittening box

Around week seven she will start inspecting wardrobes, drawers and the space behind the sofa. Beat her to it: a large cardboard box or a purpose box, low enough to step into, high enough to contain newborns, lined with washable bedding, in a warm quiet room. Show it to her, then leave her to decide. If she chooses somewhere daft anyway, it is easier to move the box to her spot than to argue.

Birth and the first hours

Most cats manage alone and prefer it. Labour signs include restlessness, nesting, calling, and a drop in appetite; her temperature dips about a day before. Kittens usually arrive every 30 to 60 minutes, each in its own sac, which she opens and cleans. The whole litter commonly takes two to six hours. Keep your distance, keep the room warm, and keep your vet's number in reach.

Call the vet if she strains hard for over an hour with no kitten, if more than two hours pass between kittens when you know more are coming, if there is green or bloody discharge before the first kitten, or if she seems weak or feverish at any point. These are the situations where hours matter.

The first week after

Newborn kittens cannot see, hear or regulate their own temperature. Their world is mum's warmth and milk. Weigh them daily on a kitchen scale: steady gain of ten to fifteen grams a day is the sign everything is working. A kitten who cries constantly, feels cold, or is repeatedly pushed away from the group needs help quickly, and that help is a vet or an experienced hand with kitten milk replacer, never cow's milk.

Verdict by household

For a first-timer, the best single move is an early vet visit: confirming the pregnancy early gives you the kitten count and a plan. For a multi-cat home, give her a room of her own from week seven; other cats hovering near the box is a common cause of her moving the litter somewhere worse. For anyone who took in a stray, assume any unspayed female over five months old can be pregnant, and let the vet check before you feed her up.

After the kittens

She can come back into heat within weeks of giving birth, sometimes while still nursing. If another litter is not the plan, keep her indoors and talk to your vet about spaying once the kittens are weaned, usually around eight weeks. Our kitten first-90-days guide picks up from day one of the kittens' lives, and the litter training piece covers weeks four to eight.