Fertile window tracking

Fertile window tracking

Fertile window tracking helps identifying the days in the menstrual cycle during which pregnancy is most likely.

What is the fertile window?

5 days before ovulation and the day of ovulation.

The sperm can live inside the female reproductive system for up to 5 days, the egg survives for up to 48 hours after ovulation.

That is why the fertile window is 6 days.

When does ovulation occur?

14 days before the expected menstrual cycle day.

In a 28-days menstrual cycle it occurs on day 14.

In a 30-days menstrual cycle it occurs on day 16.

In a 26-day cycle it occurs on day 12.

The ways to identify fertile period:

1. Calendar method:

• The cycle should be tracked for 3 months
• Estimate ovulation time based on average cycle length
• This method can’t be used in irregular cycles (the cycle has to be regular for at least 3 months)

2. Basal body temperature:

• Temperature slightly rises on the day of ovulation (up to 0.5 degrees Celsius)
• The temperature is taken daily before getting out of bed
• It detects ovulation after it happens, not before

3. Cervical mucus:

• At the time of ovulation cervical mucus is clear, slippery and stretchy in order to facilitate the movement of sperms

4. Ovulation predictor kits:

• Detect LH surge in urine
• If it was positive then ovulation will most likely happen within 36 hours
• Used to time intercourse

5. Artificial intelligence-based applications

6. Ultrasound tracking by a gynecologist starting on day 9 of the menstrual cycle and every few days

Factors that affect ovulation:

• Polycystic ovary syndrome
• Thyroid disease
• Stress
• Significant weight loss/gain
• Breastfeeding
• Perimenopause

These lower the chances of overall pregnancy

Percentage of pregnancy using fertile window tracking:

• Depends on timing, age and overall fertility health for both couples
• Women under 35: 25 % per cycle
• Women between 35-37 years: 20% per cycle
• Women between 38-40 years: 10% per cycle
• Women over 40 years old: less than 5%

Cumulative pregnancy rates:

• 70% within 6 months
• 85% within 12 months
• 90% within 24 months

These percentages are for healthy young couples with no fertility problems.

Dr Najeeb Layyous  F.R.C.O.G

Consultant Obstetrician, Gynecologist and Infertility Specialist