Two studies testing timing

[rainbowflower]

Here are the links to two really interesting studies I've found which tested timing:

"Timing of Sexual Intercourse in Relation to Ovulation — Effects on the Probability of Conception, Survival of the Pregnancy, and Sex of the Baby"

Results
In a total of 625 menstrual cycles for which the dates of ovulation could be estimated, 192 pregnancies were initiated, as indicated by increases in the urinary concentration of human chorionic gonadotropin around the expected time of implantation. Two thirds (n = 129) ended in live births. Conception occurred only when intercourse took place during a six-day period that ended on the estimated day of ovulation. The probability of conception ranged from 0.10 when intercourse occurred five days before ovulation to 0.33 when it occurred on the day of ovulation itself. There was no evident relation between the age of sperm and the viability of the conceptus, although only 6 percent of the pregnancies could be firmly attributed to sperm that were three or more days old. Cycles producing male and female babies had similar patterns of intercourse in relation to ovulation.

http://www.nejm.org/doi/full/10.1056...99512073332301




"Sex ratio associated with timing of insemination and length of the follicular phase in planned and unplanned pregnancies during use of natural family planning."

In the context of ongoing debate over the determinants of sex ratio, the authors used data from a multinational study of pregnancies among natural family planning (NFP) users to investigate the association between timing of conception or follicular phase and length and the sex ratio at birth. They also explored whether a pregnancy's planned or unplanned status affects those associations. A multicenter, prospective study of pregnancies among women using NFP was conducted. The women maintained NFP charts of their conception cycles, recording acts of intercourse and signs of ovulation such as cervical mucus changes and basal body temperature. Charts were used to identify the most probable day of insemination relative to the day of ovulation and length of the follicular phase of the cycle. The sex ratio (number of males per 100 females) for 947 singleton births was 101.5, not significantly different from the expected value of 105. The sex ratio did not vary consistently or significantly with the estimated timing of insemination relative to the day of ovulation, with the estimated length of the follicular phase, or with the planned or unplanned status of the pregnancy. Study findings suggest that manipulating the timing of insemination during the cycle cannot be used to affect the sex of offspring.

http://www.ncbi.nlm.nih.gov/pubmed/9647580

[Sassy]

Hhhmmmmm - well, everyone always says timing is the least important factor!

[rainbowflower]

agree, and figure 4 in the first link ( http://www.nejm.org/action/showImage...332301&iid=f04 ) seems pretty conclusive...

[zanacal]

agree, and figure 4 in the first link ( http://www.nejm.org/action/showImage...332301&iid=f04 ) seems pretty conclusive...

All over the place! Thanks for posting

[LolaInLove]

Thanks for posting, Rainbow! All in the diet, baby!

[happyheart]

Great post!! I will be dtd through ovulation and am happy to hear this.

[2pinkNoblue]

once I think I have made a plan then i read conflicting info it makes me think its all up to chance!

[zanacal]

With timing, that's the conclusion most of us have come too - that there's just too much conflicting information for it to matter so why worry about it and why not concentrate on the aspects where there's more evidence (like diet!).

[love being a mummy]

once I think I have made a plan then i read conflicting info it makes me think its all up to chance!

I am feeling the same way. The more I read, the more conflicting advice I see, and I am starting to think that maybe we can't control it at all. It's just luck, chance, fate. Maybe getting our DG is just a coincidence.

[nuthinbutpink]

I am feeling the same way. The more I read, the more conflicting advice I see, and I am starting to think that maybe we can't control it at all. It's just luck, chance, fate. Maybe getting our DG is just a coincidence.

You have to focus on your diet and eating habits. There actually is a fair amount of research in this area and it is all consistent even going back to the French Gender Diet. Timing is not effective for swaying.