Fertility and Your Menstrual Cycle
The most fertile time of your menstrual cycle occurs around ovulation, when your ovaries release a mature egg for fertilization. This window varies from woman to woman, depending on the length and regularity of her menstrual cycles. For those with a 28-day menstrual cycles, ovulation usually occurs between days 13 to 15, with day 1 considered to be the first day of menstrual flow (not just spotting!).
An egg survives for about 12-24 hours after ovulation. Sperm, on the other hand, can stay alive in the body for 3 to 5 days, making a woman fertile for about a six-day window.
Best Time to Have Sex to Conceive
Because sperm lasts several days in the human body, and a woman’s egg only lasts a maximum of 24 hours, the best time to have sex in order to achieve a pregnancy is a few days before ovulation occurs. Couples should have sex at least every 2 days starting five days before ovulation until the day after ovulation.
To make the most out of each session of sexual intercourse, you need to know when you are ovulating. There are several methods to detect the start of ovulation.
Changes in cervical mucus. Cervical mucus can be an indicator of ovulation. Before ovulation, cervical mucus is dry and sticky. As ovulation comes closer, it may take on a creamier consistency. Right before ovulation, cervical mucus tends to take on the consistency of a raw egg white and may become more slippery. For some women, charting cervical mucus can help identify cycle patterns, however others may find it difficult to reliably detect changes month to month.
Charting Basal Body Temperature (BBT). Charting your BBT can help you detect patterns of ovulation. Most thermometers on the market can be used, as they generally measure temperature to the tenth degree. When taking your temperature every morning before you get up, you may detect a 0.4 degrees Fahrenheit increase after ovulation. As described above, a woman is actually most fertility prior to ovulation, so this method is most helpful to plan around upcoming cycles.
Ovulation Predictor Kits (OPK). These at-home tests allow you to predict when you will ovulate. The test works by measuring urinary luteinizing hormone (LH), a hormone that sharply rises mid-cycle to signal to the ovary to release an egg. Ovulation should occur in the 12 to 48 hours after you detect a rise in LH. The surge lasts up to 36 hours, meaning that the test is only positive for 1-2 days. Importantly, OPKs can be misleading in some women, particularly in those with polycystic ovarian syndrome.
Physical signs of ovulation. Physical signs of ovulation may vary for each woman, but may include light spotting, abdominal cramping, breast tenderness, and bloating.
If you’re experiencing trouble conceiving or suspect an infertility condition, you should consider consulting with a fertility specialist.
Article reviewed by: Dr. Ann Korkidakis, Boston IVF
Dr. Korkidakis is a valuable member of the Boston IVF physician team and is also a Clinical Fellow in Reproductive Endocrinology & Infertility at Beth Israel Deaconess Medical Center/Boston IVF. She graduated with honors from McGill University with a major in Anatomy and Cell Biology and went on to complete a medical degree at McGill University followed by a 5-year residency in Obstetrics and Gynecology at Queen’s University. She received training in Reproductive Endocrinology and Infertility from the University of British Columbia.
Her interest in promoting reproductive health and access to fertility care for all individuals needing assistance building their families led her to complete a Masters in Public Health at Johns Hopkins University. Her work on identifying the fertility needs of adolescents and young adults with cancer was awarded the Fertility Preservation Prize Paper at the American Society for Reproductive Medicine Annual Meeting.
Dr. Korkidakis is an active candidate for the American Board of Obstetrics and Gynecology, and a member of the American Society for Reproductive Medicine, the New England Fertility Society, Pacific Coast Reproductive Society, the Canadian Fertility and Andrology Society, and the American College of Obstetricians and Gynecologists. As a native of Canada, Dr. Korkidakis enjoys exploring this beautiful country with her family on her spare time.
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