Irregular Menstrual Cycles and Fertility

The Ideal Cycle

The main concern with irregular cycles for women who want to conceive is that they might not be releasing a mature egg, or ovulating, during their cycles. Here's a quick rundown from Dr. Welt on how the menstrual cycle works in a textbook 28-day cycle. The menstrual cycle is broken down into two phases. The first phase is called the follicular phase. It lasts about 14 days, from the first day of your period until the day of ovulation. During the follicular phase, three things happen:

• The egg follicle begins to mature in the ovary.
• The uterine lining thickens and becomes ready for a fertilized egg to implant.
• At day 14 of a textbook cycle, high levels of estrogen cause a surge of a hormone called luteinizing hormone, which triggers ovulation.

Following ovulation, the luteal phase begins. The luteal phase lasts for another 14 days, and is marked by high levels of progesterone and estradiol. These hormones keep the uterine lining ready for implantation. If no embryo implants, progesterone and estradiol levels fall and the uterine lining is shed through menstruation.

Menstruation Doesn't Equal Ovulation

"I knew my cycles were irregular, but I figured that since I was still menstruating, I would go ahead and try to conceive and have a baby," said Chavie. "It didn't quite work out that way."

Ovulation is key to conceiving. You can't get pregnant without releasing an egg. Even if a woman has some periods, it doesn't mean that she is ovulating. The body can still shed the uterine lining without ovulation occurring. In fact, according to Dr. Welt, a classic study from the 1960s found that women with cycles shorter than 21 days or longer than 35 days are much more likely not to be ovulating during their cycle.

Even if a woman with irregular cycles is still ovulating, fertility might be affected. If a woman's cycle is very long, for example, lasting 40 or 50 days, it can be hard for a couple to figure out when the egg is released and when they should be having intercourse.

"We just had to go with my best guess when we were trying to conceive," said Longoria. "And it wasn't working!"