Watch out this is long
I found this on babyzone:
Q: "I am currently about fifteen pounds underweight. Though I have very regular menstral cycles, my husband and I have had no luck in trying to conceive for the first time. We've been trying for seven months. Could the fact that I'm underweight be a factor in our problem?"
A: "Maybe! If an invidual is too far underweight, and therefore has a small percentage of body fat, menstrual cycles may become abnormal or even stop altogether. It would be interesting to know if the second half of your cycle, the part of the cycle after ovulation, is normal. A combination of a basal body temperature chart and a day 21 progesterone level should answer this question."
This is from am-i-pregnant.com:
"Q: During my last visit with my reproductive encrinologist, I was told I needed to gain weight. I'm 5 feet 3 inches tall and only weigh 98 lbs. I have heard that overweight women have some difficulty getting pregnant, but I assumed my weight was fine for conception. Should I slow down my exercise program? Thank you for your help!
A: Excessive exercise and dieting account for most of the ovulation disorders. Whether you are obese or underweight, your chances for a successful conception decrease. There needs to be a balance there, so your body does not feel "threatened" by poor nutrition or too many calories.
Normal Weight Ranges For Women:
Height - Small Frame - Medium Frame - Large Frame
4' 10" - 102-111 lbs - 109-121 lbs - 118-131 lbs
4' 11" - 103-113 lbs - 111-123 lbs - 120-134 lbs
5' 0" - 104-115 lbs - 113-126 lbs - 122-137 lbs
5' 1" - 106-118 lbs - 115-129 lbs - 125-140 lbs
5' 2" - 108-121 lbs - 118-132 lbs - 128-143 lbs
5' 3" - 111-124 lbs - 121-135 lbs - 131-147 lbs
5' 4" - 114-127 lbs - 124-138 lbs - 134-151 lbs
5' 5" - 117-130 lbs - 127-141 lbs - 137-155 lbs
5' 6" - 120-133 lbs - 130-144 lbs - 140-159 lbs
5' 7" - 123-136 lbs - 133-147 lbs - 143-163 lbs
5' 9" - 129-142 lbs - 139-153 lbs - 149-170 lbs
5' 10" - 132-145 lbs - 142-156 lbs - 152-173 lbs
5' 11" - 135-148 lbs - 145-159 lbs - 155-176 lbs
6' 0" - 138-151 lbs - 148-162 lbs - 158-179 lbs
Aside from extreme exercise and diet practices, there are eating disorders that affect ovulation and fertility in general...
Anorexia and intense exercise cause a woman's cycle to stop in it's tracks. This is known as "amenorrhoea", which means an absence of menses. There then comes a significant decrease of GnRH (Gonadotropin hormone) released from the Hypothalamus gland. Without GnRH, FSH (follicle stimulating hormone) and LH (luteinizing hormone), ovulation cannot occur.
Follow the advice of the reproductive encrinologist. Moderate your exercising and eat according to the nutrition chart your doctor will give you. If all fails, your doctor may send you to a nutritional specialist to put your weight back in normal range."
From babymed.com:
"Q: What are my chances of getting pregnant?
A: The simple answer is that there is a 20-25% chance each month of getting pregnant, a 50% chance getting pregnant after 5-6 months, and a 85% chance getting pregnant after 1 year.
However, this answer is really incomplete without taking into consideration your personal circumstances:
1. If you don’t ovulate, there is a zero % chance of getting pregnant
2. If he has no sperms, there is a zero % of getting pregnant
3. If you have had a tubal ligation, there is a zero % chance of getting pregnant
4. If you have severe tubal disease which has closed off your tubes, there is a zero % chance getting pregnant
5. If you are over 35 your chance of getting pregnant decreases by about 3 % each subsequent year
6. If you are under 35 and you have tried unsuccessfully to get pregnant for one year, your chances getting pregnant in the second yes are less than in the first year.
7. If you are 35 and over and you have tried unsuccessfully to get pregnant for 6 months, your chances getting pregnant in the next six months are less than in the first six months.
8. If your menstrual cycle is irregular your chances of getting pregnant are lower
9. If your corpus luteum phase is shorter than 12 days your chances of getting pregnant are lower
10. If you ovulate irregularly, on different days of the cycle, your chances of getting pregnant are lower
11. If you ovulate late in the cycle, after cycle day 21, mathematically you have a lower chance getting pregnant because there are less ovulations per year and also because implantation is less likely in a uterine lining that’s older than 3 weeks after the last menstrual period.
12. If you are underweight (BMI under 19.5) your chances of getting pregnant are lower
13. If you are underweight (BMI under 19.5) your chances of getting pregnant are lower
14. If you take certain medications (hormones or others) your chances getting pregnant may change
15. If you had surgery on your cervix your chances may be less
16. If you have an infection your chances may be less
17. If you use lubricants your chances may be less
18. If you have sex while standing or get up after sexual intercourse your chances may be less"
To calculate BMI:
a.) Convert body weight to kilograms.
Body weight (pounds) ÷ by 2.2 = weight in kilograms
b.) Convert height to meters
height (inches) ÷ by 39.37 = height (meters)
c.) Calculate BMI
weight (kilograms) ÷ by height in meters² = BMI
Hope some of this helps.
