How long can an unfertilized egg live?

An unfertilized egg, also known as an oocyte or ovum, has a limited lifespan after it is released from the ovary during ovulation. The survival time of an unfertilized egg can vary among different species, but in humans, it typically lasts for around 12 to 24 hours.

Here's a detailed breakdown of the lifespan of an unfertilized egg in humans:

1. Ovulation: The process of ovulation occurs when a mature egg is released from one of the ovaries. Ovulation usually happens once during each menstrual cycle, around day 14 for someone with a regular 28-day cycle.

2. Fertilization Window: After ovulation, the egg enters the fallopian tube, where it can potentially encounter sperm cells. If the egg is fertilized by sperm within approximately 12 to 24 hours of ovulation, it can develop into an embryo.

3. Degeneration and Resorption: If fertilization does not occur within this timeframe, the unfertilized egg will undergo degeneration and resorption. This process involves the breakdown of the egg by the body's natural mechanisms, and it is typically completed within a few days.

4. Menstrual Flow: The lining of the uterus (endometrium), which had prepared for the potential implantation of a fertilized egg, starts to break down and shed due to the declining levels of hormones. This process results in the menstrual flow or period, which typically begins around 14 days after ovulation if the egg remains unfertilized.

It's important to note that various factors, including hormonal imbalances, certain medical conditions, or medications, can affect the timing of ovulation and the lifespan of an unfertilized egg. If you have concerns or questions about your reproductive health, it is advisable to consult a healthcare professional.