4 Reasons Your Pregnant Guppy Died Before Giving Birth

pregnant guppy dead

Did your guppy suddenly die before giving birth?

It sometimes happens to guppies. The most common reason a pregnant guppy dies before birth is too much stress. But there are other preventable reasons.

This article will cover those reasons. Additionally, we will briefly mention how to properly care for a pregnant female and prevent your female guppy from dying before birth.


Pregnant guppies often die before birth because of stress. Think about it, carrying around 30+ guppy fry in her womb is taxing and stressful on the body!

Even worse is that bad water parameters, a small tank, bullying, and other conditions can further stress your pregnant guppy and cause her death.

The solution to this is simple:

Ensure proper water parameters, plenty of space, and remove fish that bully the pregnant guppy. I recommend a separate tank for pregnant guppies, but you do have to make sure the water parameters and quality is similar to her original tank.

You definitely don’t want to switch a pregnant guppy to a tank with radically different water parameters – that will only stress her out more!

Signs Your Pregnant Guppy is Stressed

Here are some basic behavior patterns that indicate your pregnant guppy is stressed.

  • Swimming in circles or erratically.
  • Not eating.
  • Staying at the bottom of the water column.
  • Discoloration.
  • Unusual breathing.

Bad Water Parameters or Water Quality

Bad water parameters or water quality can stress your guppy. It can also lead to a weaker immune system, which means more sickness.

All that combines to greatly increase the chance a pregnant female dies before birth. This is why all these reasons are related, but it mostly comes down to water parameters and water quality.

Guppies like a pH that ranges from 6.9 to 7.7. That’s a normal pH and not difficult to maintain, thankfully.

As for water temperature, guppies like the water temperature at 75 Fahrenheit to 82 Fahrenheit. You can go as cold as 68 Fahrenheit or as high as 85 Fahrenheit.

I recommend 80 Fahrenheit for pregnant females. Remember, guppies are a tropical fish that thrive in warm water.

Maintaining this temperature requires a heater, so make sure you have a heater for your guppies.

Water quality is also important. You obviously want a filter to keep the water clean. Plants are another great way to maintain a clean tank.

Now, cleanliness of the tank is not really about algae. Guppies actually like algae.

A clean tank involves the filter removing bacteria that can cause problems for your guppies. The most important thing to do to keep your water clean?

Frequent water changes.

I recommend 10% per week at a minimum. If you have a smaller tank (ie. 10 gallons) without plants, then you should up that to 50% water changes per week.

Prior Sickness

I already mentioned how stressful pregnancy is for guppies.

That stress from pregnancy plus with fighting off a sickness greatly increases the chances of death.

The most common sickness that causes death in pregnant guppies is probably ick. You’ll know your guppy has ick if you see white spots on its skin.

Ick is contagious, so you should place any fish with ick in a quarantine tank. Make sure to add ick medicine to the quarantine tank and the main tank to prevent an ick outbreak.

Ick is pretty nasty and can wipe out an entire tank of fish. It’s definitely something you want to keep under control before it becomes a problem.

Old Age

Finally, old age can lead to problems with your guppy. There isn’t much you can do about this.

Guppies live about 2 years. The females will give birth once a month for their entire life.

This means that an elderly guppy can still give birth. But her body will be much weaker and less able to handle the stress from pregnancy.

With that in mind, if your guppy is over 18 months old and dies during pregnancy it was probably from old age.

Proper Care for Pregnant Guppies

Caring for a pregnant guppy is not difficult. It’s actually pretty easy if you know what to do. This section will cover some tips on how to care for a pregnant guppy.

Proper Water Parameters

Guppies like a pH of 6.9 to 7.5. The exact pH isn’t so important. The important part is that you have a stable pH for your guppies.

You can get away with a little bit in both directions, but it’s important to maintain proper pH if you have a pregnant guppy.

I recommend sticking to 7.3 pH if you have a pregnant guppy – they like alkaline water.

As for hardness, 9-10 dGH is the minimum hardness for guppies. But the harder the water the better it is for your guppy.

Proper Water Temperature

Water temperature is also important for keeping a pregnant guppy healthy.

I recommend 75 Fahrenheit to 80 Fahrenheit for pregnant females. Again, guppies can go much lower than 75 Fahrenheit and little over 80 Fahrenheit, but they prefer warm water to cold water.

Give them what they want and keep the water at 75 to 80 Fahrenheit.

Plenty of Space

Guppies do not need much space – they aren’t territorial and are a small fish.

However, a pregnant female may get bullied by other fish, so it’s a good idea if you allow her to have more space to avoid fighting.

Fighting obviously stresses the fish out.

The exact amount of space is way beyond the scope of this article. As a rule, if you see the fish fighting OR it simply looks crowded, then you need to figure out a way to give your female more room.

Regular Feeding

Finally, you want to regularly feed a pregnant female. Remember, she has a lot of fry in her womb that use up a lot of energy.

I recommend feeding a pregnant guppy a few times a day with a fortified food. Also, make sure that she receives plenty of protein.

Don’t feed your pregnant guppy bread or goldfish food – it’s not good for guppies!

Regular feeding ensures the health of the pregnant female and the health of the fry. You do not want a malnourished fish giving birth!

What happens to the fry when a pregnant guppy dies?

This depends on how far along in pregnancy the guppy was when she died. If she dies during birth, then the fry will usually live.

If she dies before she gives birth, then the guppy fry will die inside her. Dead guppies cannot give birth.

Should I quarantine my pregnant guppy?

Whether or not you should quarantine your dead guppy depends on a few factors:

  • How crowded is your main tank?
  • Can you maintain a quarantine tank?
  • How far long in the pregnancy is your guppy?

Basically, only do a quarantine tank if you have a crowded main tank and can maintain a quarantine tank.

Also, if the guppy is going to give birth in the next few days, then you should not move her because moving her will stress her out.

My recommendation?

You do not need to quarantine a pregnant guppy unless you have a really small, crowded tank.


That’s it for why your pregnant guppy suddenly died. If a pregnant guppy dies, it’s almost always from stress due to pregnancy combined with underlying stress from a crowded tank, bad water parameters, or bad water quality.

Sometimes she might die during pregnancy if she has a prior sickness such as ick. Other times the first pregnancy might kill a guppy.

Of course, sometimes the death is simply her body shutting down because of old age.

Anyway, the best way to prevent your pregnant guppy from dying is to ensure you have proper water parameters, clean water, the right temperature, and eliminate contagious diseases from your tank.

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