Pregnancy day by day
 Week  Day  
1       1 One mating may be enough for the female to ovulate. The male has barbs on his penis which hurts tremendously when he pulls it out and this causes the female to release its eggs. The female does not even need to be in heat to release the eggs, a mating is enough for it to happen and to raise the Luteinization Hormone (LH).  The mating does not need to take place when the female is in heat, for her to become pregnant. It happens that males do mate females that are not in heat and who are not willing, and this can still cause a pregnancy. 

LH is needed to reach the final maturation of the egg cells and for the follicles to rupture and the eggs to come out into the fallopian tubes.

Probably a single mating will not be enough, but you should still not keep the cats together for too long as it can then be difficult to determine when the kittens will come. The optimal mating time is 3 days.

The sperm migrate through the cervix.

 2 Ovulation.
This occurs 24 to 48 hours after the mating happened.
The eggs are undeveloped and unable to be fertilized.
Since the eggs are susceptible for 24-36 hours, several males can become dads to the same litter.
 2-3 The sperm reach the egg in the fallopian tube.
Progesterone rises 48 hours after ovulation, samples can be taken 3-4 days after mating.

When a sperm penetrates the egg, fertilization occurs and the core is fused. A zygote is the result of fertilization, that is, a fertilized egg. Now the first chromosome set to form. The zygote is ready for its first cell division.

Fertilization occurs in the fallopian tubes that extend from the ovaries to the uterus

 5-6 Fertilized eggs migrate down the fallopian tube and into the uterine horn. Through the continued migration, space for the fetuses in the uterine horn is also freed.
During the migration, the fertilized egg divides several times and forms an early embryo, a so-called blastocyst.
 2 11-14

The blastocysts attach to the uterine wall, 13-14 days after mating.
The placenta begins to develop on day 14 and also the spinal cord.
Blastocysts grow and develop into embryos.

The placenta (in the form of a girdle) and umbilical cord are developed.
A yellow sac (yellow sac or yellow bladder; in the vertebrate animals a sac containing the nutrition(yellow) for the fetus) provides nutrition until its placenta and umbilical cord have developed sufficiently.

Both the number of eggs discharged and the space in the uterus affect the litter size.

Over the next two weeks, all organs will develop.

3   15-18 The circulatory system begins to develop on day 15.
Day 16-17 the heart starts beating.
Day 18 is the embryo (8mm).

The nipples are starting to turn pink and getting larger so-called. "Raspberry nipples". The fur on the tummy around the nipples starting to thin out slightly.

Day 19, the embryo is now about 10 mm long and stuck in the uterine mucosa.
The spine develops and the jaundice begins to shrink.

Over the next two weeks, important organs will develop such as the brain, spinal cord. Followed by the spine, head, heart and sensory organs. The central nervous system develops throughout pregnancy.

 4 22-28

One thing to keep in mind is that weeks 3-5 can be said to be a critical time when the female should be saved all kinds of stress, it is often here that goes wrong. Then the placenta takes over the supply from the yellow body. If this does not go the way, the fetuses will be rebuilt. This is often the case when the female suddenly tapers off again at 7 weeks and all signs of pregnancy disappear.

Now the uterus starts to expand and hormone changes in the cat's body occur. Some cats may be nauseated while some cats may begin to feel ill the first week. It varies just as for pregnant women.
She may become a little apathetic, possibly refuse to eat and vomit.
Having free access to food facilitates helps, this is often seen day 22-42.

From day 20-22 you can see the heartbeats.
If heart sounds appear, the fetus is at least 20-22 days old.
On day 22, the embryo develops head, legs and eyes and it receives nutrition from the mother via the newly formed placenta and umbilical cord.

Day 23-24 is the embryo (17-18 mm).
Head, jaw, cheeks, nose and mouth develop.

 4-5 26-30

The fetuses are now walnut-sized, and easy to count.
This is the best time to count them, but be careful.
An experienced breeder or veterinarian may know if the female is pregnant at day 20-30 and up to day 35.

Ultrasound can be done from day 21, but preferably day 28 (depends on UL apparatus and practitioners).
(Personally I do not recommend going to the veterinarian to see if your female is pregnant, you will know in time anyway and even if she is pregnant now, it's not sure she will still be when it's time for delivery. Also 5 kittens on UL could easily become 3 kittens when it's time for the birth. If a kitten is lost during pregnancy the female body often takes care of it and the features will regress).

Production of progesterone is now completely taken over by the placenta.

Now the palate and reproductive organs are beginning to develop. The fetuses can now be seen with ultrasound.

Production of the hormone progesterone (yellow body hormone, female sex hormone which is a prerequisite for pregnancy to progress normally) is now completely taken over by the placenta and the embryo is considered fetal.

Day 25-26 (20-21 mm).
Day 27-28 (25 mm) and now called fetus, all internal organs have been developed.

 5 29 

You may now start increasing the female's food if she does not have free access. Feel free to provide growth food for pregnant females or kitten food. Do not add vitamins and minerals. However, make sure the female does not become obese as it can cause problems at birth.
The fetuses are already small mini cats and about 25-30 millimeters large.

The female eats about 25% more food in the last 4 weeks of pregnancy.

 6  32-38 The female's stomach begins to become visibly swollen.
Day 32 (28 mm) and day 35 (35mm)
Day 38 (45mm) and weighs about 14g and has no coat yet.
35 The stomach begins to grow and becomes visibly bigger.
38 The reproductive organs are fully developed.
40 From day 40, the fetal skeleton has started to mineralize and can now be seen on X-rays.
42 From day 42 you may start to feel fetal movements.
 7   43 Now it is easy to know the kittens, to count them may be difficult.
On day 43, the fetus is 80 mm.
44-46 On day 44, the fetus begins to develop fur.
It is now easy to feel the kittens. Counting them might be more difficult.
Day 46 (95 mm)

The female is starting to clean her self more, her breasts are getting bigger.
She can also become a little restless and start searching for a place where she can have her kittens.

The fetuses are now starting to get a little fur.


Since the female's stomach is now filled with kittens, the female may partially lose appetite.
She should eat several small meals a day or even better have free access.

If the female has a hard time cleaning herself, you can help her a little.
Her vagina and breasts can be gently washed with lukewarm water.

You can now easily feel the movements of the fetus.

From day 50 (110 mm), the colors begin to emerge.
Day 55 (125 mm)


The fetus grows to about 15 cm.
Day 56, The fetus now has a proper coat.
The kittens have now also got their coat color if they are not colorpoint as all the colorpoints are born white.

Kittens born before day 58 usually have a very hard time surviving.

60 Day 60 (143 mm)

You can now start taking the temperature of the cat.
If you keep track of your cat's temperature, it will probably drop below 38.9 C to about 37,5 C just before birth.
Take it at about the same time for the remaining days.
However, I do not recommend temping myself, but instead, keep an eye on the female. 

63 Day 63 (150 mm).
There may now be some milk coming from the nipples
10 64 12-24 hours before delivery, the temperature drops to about 37.5 C.
Some discharge may occur, it might be some blood in the discharge.

Expected delivery. Most deliveries occur between days 63 and 67.

The kittens are in two different horns in the female's stomach.
It is not uncommon for the female to first empty one horn and then take a break; it may take up to a day before the next horn is emptied with the rest of the kittens.
However, you should always call a veterinarian if something does not feel good or you feel worried. Better to call once too many times than to few. Stress triggered by the environment around the cat can prolong pregnancy.

Parts of the cerebrum and eyesight are not fully developed until the kitten is born.

69-70 If the cat has not started with the delivery yet and she is on day 70, and you are sure the counting is correct. You should contact a veterinarian for advice.

Av: Malin Sundqvist