Why would my RE schedule my IUI less than 24 hours after HcG trigger (no natural LH surge)?

My IUI was scheduled at 14 hours post HcG trigger.  My LH had not begun to surge . . negative OPK's and confirmed with a blood test that it was very low (3.9).

I took my HcG trigger on CD13 at 10:00 p.m. as my largest follie was 21mm and a few others were close in size.  My E2 levels were super high at 10,000 CDN (2,700 US), and I took only 1/2 the HcG trigger (5,000 units).

My RE did not explain to me why they did my IUI 14 hours post trigger, and I can't find much information to back this timing up.

Did this happen to anyone else?  What could be the reasoning behind it?

I'm driving myself nuts doing research and trying to figure this out - - wish I could get an answer out of them!!

Lindsey

[Elaine Brown, MD]

Hi!
I will give you my best guess, since obviously I can't know what your MD was actually thinking.

The interval of peak fertility is actually the 24 hours before the egg is ovulated.
The HCG shot (which simulates the LH surge) causes the ovum to mature and rupture--ovulate almost exactly 36 hours later.

So, he was probably trying to ensure that the sperm were ready and waiting for the egg as soon as it was released.   Data suggest that is a good idea.  Also, sperm can survive for up to 3 days in the female reproductive tract, so better to be early than to miss the big event!

Hope this helps!
Dr B