Why Did My Guppy Fish Die After Giving Birth? (Explained!)

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Guppies are easily one of the most popular fish in the hobby today. To be fair, their popularity hasn’t really dropped since the late 1960s.

One of the things that makes them so popular is the ease with which they breed. Guppies are baby-producing machines. However, producing all those babies can sometimes lead to female guppies passing away straight after giving birth. If you are new to guppy keeping you may find yourself wondering ’Why did my guppy fish die after giving birth?’

Some reasons female guppies die after they give birth include stress before or during the birth, incorrect water temperature, poor water quality, or because the female was old or sick.

I have been keeping guppies for nearly 30 years. I have kept dozens of different strains and produced countless babies over that time. Even with all that experience, I still occasionally lose a female guppy either during birthing or immediately afterward.

Female guppies are constantly pregnant. They can produce thousands of babies over their lifetime. Giving birth to between 40 and 100 babies every 30 days can take its toll on the female guppies.

Reasons A Female Guppy May Die After Giving Birth

  • Stress
  • Incorrect water temperatures
  • Poor water quality
  • Old or sick


Guppies are easily stressed, and that stress can prove fatal. Stress can be caused by so many factors, but the most common reasons are constant attention from male guppies, bullying from other fish, or just fish keepers constantly messing about with the tank.

Male guppies are extremely persistent in wanting to breed with the females. The fact that a female is already pregnant, or worse, in the process of giving birth doesn’t stop them. This constant attention can really take its toll on the females.

I have found the best way to reduce unwanted attention is firstly to get the male to female ratio right. I like to keep a minimum of 3 female guppies to every male. Secondly, I try to provide as many hiding places and line of sight blocks as I can.

If the female can get out of the male’s line of sight, there is a good chance she can avoid his attention for a short while. Typically I use live or fake plants to create the sight blocks. I have had great success with these fake plants that I picked up from Amazon.

Providing hiding places and line of sight blocks also helps if your female guppy is being bullied by another fish. If she can get away from the bully fish, even for a short while, it gives her a chance to rest. When it comes to fish bullying, out of sight is out of mind.

The third and final major stress factor is us fishkeepers. Watching guppies give birth is fascinating, especially if you are new to it. I still love to watch my female guppies give birth. These days however I try to do it from afar so as not to stress the female.

Another major stress factor caused by us fishkeepers is moving the female guppy to a birthing box. The poor fish, heavily pregnant, gets scooped up and placed in a clear floating box with nowhere to hide. She will feel vulnerable at a time when she needs to feel secure. I would recommend NEVER moving a pregnant guppy into a floating birthing box.

Incorrect Water Temperatures

Incorrect water temperature at any point during the pregnancy can cause the female guppy to abort the pregnancy and reabsorb the babies. If the water becomes too cold or too hot at the point of giving birth, the stress levels placed on the female guppy can prove fatal.

If I know my females are due to give birth I will pay particular attention to the aquarium water temperature to make sure it doesn’t fluctuate too much.

Poor Water Quality

Poor water quality can kill your guppies at any time, but it can be especially lethal to females when they are giving birth.

If you are unfortunate enough to have an ammonia spike when your female is giving birth, the stress placed upon her may cause her to pass away.

Female Guppy was Old or Sick

Female guppies continue to produce babies no matter how old they get. Needless to say, being old and pregnant makes the chances of passing away during birthing even higher. The same is true if your female is unwell. There is only so much stress she can take.

Ways To Prevent A Female Guppy Dying During Birthing

There are lots of things we as fish keepers can do to help prevent our female guppies from dying during birthing.

I try to make sure the aquarium is as stress-free as possible. I keep an eye on both the water temperature and the water parameters by testing them with my test kit. I also check on the females on a regular basis to make sure no fish, especially other guppies, are harassing her.

In my experience, moving the guppy into a breeder box prior to giving birth is a massive mistake. Providing there are adequate hiding places and line of sight blocks, she will be fine in the main aquarium. I like to add a large clump of Java Moss. The female can get right into the moss and out of sight of everybody.

In Conclusion

Guppies are amazing fish. They are colorful, friendly, and easy to breed. Sometimes, however, the females can pass away during or immediately after birthing.

There are many reasons why a female guppy might die, but the biggest cause is stress. It is our job as fish keepers to keep those stress levels down to a minimum.

About the Author

I’ve been keeping, breeding, and showing tropical fish for nearly 30 years. Over that time I’ve done it all! I’ve had great success and I’ve made some really foolish mistakes (like the time I bought an Asain Walking Catfish). Read more…
Richard James