Hi, Warfarin is a medication that is commonly used as a blood thinner to prevent blood clots. It is not recommended for use during pregnancy because it can cross the placenta and potentially harm the developing fetus. Warfarin use during pregnancy has been associated with an increased risk of birth defects, bleeding in the fetus, and other complications. If you are taking warfarin and you or your partner are planning to conceive, it is important to speak with your healthcare provider. They can evaluate your situation and determine if warfarin is safe to continue taking or if an alternative medication should be considered. In terms of your ability to impregnate your girlfriend, warfarin is not known to directly affect male fertility. However, certain medical conditions that require warfarin treatment, such as blood clots, can sometimes affect fertility in both men and women. Additionally, other factors such as age, the timing of intercourse, and underlying medical conditions can also affect fertility. If you and your girlfriend have been trying to conceive for a year without success, it may be a good idea to speak with a healthcare provider who specializes in fertility. They can evaluate both of you for any underlying medical conditions that may be affecting fertility and provide recommendations for the next steps. Overall, if you have any concerns about the potential effects of warfarin on pregnancy or fertility, it is important to speak with your healthcare provider. They can provide individualized guidance based on your specific situation. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Priyanka, General & Family Physician