Ovulation is the small window of time when a mature egg releases and a woman can become pregnant.  Ideally, ovulation occurs around 14 days after the first day of the period (if you’re already menstruating) due to adequate levels of Estradiol, LH, and FSH.  Historically, women that lived less modernly, would ovulate around the time of the Full Moon (approximately every 29.5 days).  Just like the Follicular Phase, Ovulation occurs prior to your very first period or before your cycle returns after postpartum or other times of amenorrhea (times when you aren’t having a period for multiple months).

The Hypothalamus and Pituitary Gland (located in your brain), and Ovaries communicate to ensure a balance of hormones are produced. When FSH has been able to quietly whisper to Luteinizing Hormone (LH) so that multiple follicles mature, the follicles release Estradiol, increasing this hormone to a moderate and sustained level.  This causes LH to receive the signal to surge just before ovulation.  At this point, vaginal mucous should be a slippery egg-white consistency, known as fertile-quality mucous.  This LH surge allows a follicle to complete its final maturation enough to rupture and release an ovum (the Latin word for egg).  If you begin testing with LH strips once you see fertile-quality cervical fluid, you should catch an LH surge (though this does not confirm ovulation).  When this surge occurs, within 16-36 hours an ovum can complete its final maturation and can release.  When, or if, ovulation occurs, the fiber-like strands that wave near the ovary encourage the ovum to move towards the fallopian tube where fertilization is now possible for the next 16-36 hours.  If conception does not occur within this approximate window, the egg will begin to disintegrate, and your body will begin to prepare for menses.

If sperm were present from five to seven days prior to, or 16-36 hours after ovulation, it is possible for fertilization to occur and pregnancy to begin (so obviously conception day isn’t always the day of intercourse).  The health of the sperm will determine how long they can survive and how far they can travel through cervical fluid to reach the egg in the fallopian tube.  Likewise, fertile-quality cervical fluid, and a vaginal pH between 3.5-4.5, will provide a supportive environment for sperm to travel with appropriate acidity, and a balanced vaginal microbiome.  As a side note, caffeine intake has been shown to make sperm travel faster; however, this caffeine intake may also mean that unhealthy sperm may be more likely to reach an egg for fertilization, contributing to an unhealthy pregnancy and conception.

Nutritional intake from both male and female equally contribute to this fertile balance.  Gut microbial balance is similar to vaginal microbial balance, which will affect cervical mucous.  Stress (which can be as simple as too much busy-ness or as complicated as mental abuse and lack of sleep) can encourage the body to delay ovulation when it is safer for a baby to be conceived.  All these influences on how difficult it may be to obtain a healthy pregnancy really make us take a look at our lifestyle choices in the year prior to conception.

If conception does occur, the cells of a new baby immediately begin to multiply and create genetic code that will determine the health of the placenta, the health of the pregnancy, and all the traits that this baby could potentially express.  Within seven days of ovulation, these cells (which are still roughly in the shape of a ball) will travel down the fallopian tube to implant.

Rarely, multiple follicles mature and release in the same cycle.  However, if this occurs, you may experience a twin, or more, pregnancy.  Multiple-gestation pregnancies are becoming more common with so many hormone-disruptors in our food and products, as well as artificial methods of conception.  This is also more common as women enter the peri-menopause stage of life (up to 10 years prior to menopause), when hormonal imbalance is more likely.

LAB TESTS

LH is the main mid-cycle hormone to test.  However, if Estradiol is too high at this time, it may suppress ovulation, so it can be good to check Estradiol if you don’t think you’re ovulating.  Monitoring cervical fluid, along with at-home LH urine strips, gives you a better idea of when to lab tests during mid-cycle, especially with irregular cycles.

Mid-Cycle Optimal Blood/Serum Values

FSH: 2.5-6.0 mIU/L

Estradiol E2: 150-750 pg/mL

LH: 21.9-56.6 mIU/L

LH/FSH Ratio: >1:1