* Aggression: Males can become aggressive towards females during pregnancy, even if they've been friendly before. This can lead to fighting and injury.
* Stress: The pregnant female may feel stressed having to deal with a male, especially if he's showing signs of aggression. This can negatively impact both her health and the health of the babies.
* Premature labor: Male guinea pigs can sometimes trigger premature labor in females.
* Baby safety: Once the babies are born, the male may try to harm them.
What to do instead:
* Separate: The best option is to separate the pregnant female into a separate cage with a larger space for nesting and giving birth.
* Introduce after babies are weaned: Once the babies are weaned (around 3 weeks old), you can slowly reintroduce the parents, but this should be done with extreme caution and supervision.
Note: Guinea pigs are social animals, and it's best to keep them in pairs or small groups. If you have a male and female guinea pig, you should consider spaying or neutering them to avoid unwanted pregnancies and potential issues.