My sister had a really hard time getting pregnant. Does that mean I will, too?

Not necessarily. So many genes are involved in fertility, both in the male and in the female, that if a close relative had problems getting pregnant, it does not necessarily mean that you will also.

It's true that some of the causes of female infertility are genetically determined. For example, certain medical conditions that impact fertility – including uterine fibroids, endometriosis, and polycystic ovary syndrome – tend to run in families. So the pattern of fertility in your family may help predict how easily (or not so easily) you'll conceive.

More importantly, the number of eggs you were born with is almost certainly controlled by your genes. Even though women start life with about two million eggs, they start to lose large amounts of them right away. About 130,000 of your eggs die each year before puberty and you lose about 12,000 a year afterward. So if you start with fewer eggs, you'll run out of them sooner. If your mother or sister had an early menopause, it might indicate that you, like her, will start to run out of eggs earlier (say in your mid to late 30s) rather than later.

There are several ways your doctor can help determine how many eggs you have left (this is called your "ovarian reserve"). You can have an antral follicle count. Follicles are the small structures in your ovaries that hold the eggs. Using an ultrasound, your doctor can count the number of follicles you have at the beginning of a menstrual cycle to predict your ovarian reserve.

There are also blood tests that might be helpful. One, called AMH, tests for the amount of anti-mullerian hormone, which is produced by ovarian follicles. It can be checked at any time during your menstrual cycle. The other is called Day 3 FSH, and it measures the amount of follicle stimulating hormone (FSH) you're making. FSH is responsible for producing mature eggs in the ovaries. This test is given around the third day of your menstrual cycle.

Learn about pinpointing a fertility problem.