Yes, it is generally safe for a woman with a retroverted uterus to have sex during the first trimester of pregnancy. However, some precautions may need to be taken to ensure comfort and prevent any potential complications. A retroverted uterus, which is tilted backward instead of forward, can sometimes cause discomfort or pain during intercourse due to the pressure on surrounding organs. It is important for the woman to communicate any discomfort or pain she experiences with her partner and healthcare provider. Trying different positions that provide more comfort and reduce pressure on the uterus can help alleviate any discomfort. Additionally, using lubrication can also help reduce friction and increase comfort during intercourse. If there are any concerns or if the woman experiences severe pain or bleeding after sex, it is important to consult with a healthcare provider for further evaluation and guidance.