Tuesday, January 21, 2014

The normal thickness of the uterine wall during pregnancy

In his trial testimony, Dr. Brian Peterson said this about Laci's uterus as he observed it during the autopsy.

PETERSON: Sure. The uterus, in the first place, from the lowest portion of the uterus where it connects to the vagina, to the uppermost portion, the fundus, measured 23 centimeters. That would be roughly ten inches. As I said, normally, a uterus in the non-pregnant state may be the size of a golf ball. So an inch and a half or so. In greatest dimension, this is substantially larger. In the non-pregnant state, the uterus is almost solid muscle. There is obviously a cavity on the inside of it. But just to feel it, to make a section across, it is a relatively solid muscle. This uterus was markedly thin. The thickest, and I measured the wall of the uterus in several locations. The thickest was two millimeters, very small, all the way to nothing. Up near the top of the uterus it actually been, to my eye, abraded, and was open. So up there there was no wall. So the thickness of the wall ranged from nothing to two millimeters. So, in summary, what we have is a uterus that's much larger than a normal, non-pregnant uterus. The wall is much thinner. And as I put those two things together, I determined that that had been a pregnant uterus.

And then later he said,

PETERSON: Well, in terms of why it was the uterus there, perhaps, and other organs weren't, smooth muscle organs like the uterus in a woman, and the prostate gland in a man, tend to be relatively protected down in the pelvis, relatively resistant to degradation. So oftentimes there could be a lot of other parts missing, we'll still have that to help us determine the sex of the person. I guess that would be the main forensic significance. As I said, my other conclusion, based on the uterus, because it was enlarged and was thin, it had been pregnant. Now, at the point that I got this body, there was nothing left in the uterus. So there was no baby in there. There was no placenta in there. But the uterus remained enlarged from having been pregnant.

What he does not say is how thick a pregnant uterus normally is, especially at 32-33 weeks, Laci's stage of pregnancy on December 23, 2002.  The Defense team, and subsequently the jury, had no way to digest the information that the uterus wall was thin, 2mm at the thickest, because it had nothing to compare it to. 

I found a 1998 study that provides the information the Jury needed to draw a correct conclusion about the thinness of the uterine wall.  "Myometrial Thickness in Pregnancy: Longitidunal Sonographic Study",  is a study using ultrasound to measure the thickness of the uterine wall in 28 patients at different times during the course of their pregnancies.  These were normal pregnancies.  No difference was noted between women in their first pregnancy or in multiple pregnancies.  Laci was in her first pregnancy.  Average age of the women was 28 years, with the range from 19 to 41 years.  Laci was 27 years old.

Figure 3

Uterine wall thickness (in mm) during pregnancy. The continuous line represents the mean and the dashed lines represent the upper and lower 95% confidence intervals.  A, Anterior lower segment; B, mid-anterior wall; C, fundal wall; D, posterior wall; E, right wall; F, left wall. 
Click on the chart to enlarge it.  If you still have trouble reading it, here's a summary in data form. 

A:  7.4 mm with a standard deviation of 1.8 mm
B:  9.13 mm with a standard deviation of 1.6 mm
C:  9.48 mm with a standard deviation of 1.5 mm
D:  10.06 mm with a standard deviation of 1.9 mm
E:  8.95 mm with a standard deviation of 1.6 mm
F:  9.05 mm with a standard deviation of 1.5 mm

There's a substantial difference between the thickness of a normal uterine wall during pregnancy, and the 0-2 mm thickness of Laci's.

Dr. Peterson should have provided this information in his autopsy report, and Mark Geragos should have consulted an expert to see what it meant.  If it makes a difference in Scott's favor, as I suspect it does, Scott was entitled to have that information presented to the jury. 

If Dr. Peterson wasn't familiar with the subject, he should have done some research.  He had time between when he did the autopsy and he completed his report. 

Sunday, January 12, 2014

The debris line revisited

There's been a good healthy conversation going at George Barwood's facebook group https://www.facebook.com/#!/groups/ScottPetersonOpen/ about debris lines.  If you have not signed up for that group, I suggest you do.

One member saw the photo of People's 100, with all the water on the mudflat (Conner Recovery Site) and wondered if Conner could have come in from the North and then floated to where he was found, explaining why he was above (or North) of the debris line.  This question had been asked before by one of Scott's supporters who had been told by a friend that the mudflat floods at high tide.   

I addressed this issue on my December 5, 2004 Field Trip to the Conner Site.  The plain and simple truth is a 5.88 tide just does not produce the water on the mudflat that a 6.39 tide does.  You can go to my Field Trip for that day and see that there just is no channel of water, from any direction, that could have brought Conner to his resting place.  None.  If you do not wish to go through the entire page, these 2 pictures should settle it.  The balloons represent the approximate place where Conner was found.  Click each of the photos to enlarge.

12-5-04, 5.85 feet
12-5-04, 5.95 feet
Moreover, a 6.39 high tide is a rarity on the mudflat.  Here are the statistics for the period from December 24, 2002 to April 14, 2003:

217 high tides recorded

46 high tides (21%) at or above 6.05 feet

33 high tides (15%) at or above 6.39 feet

The high tide on April 13, 2003 was only 5.88 feet.  How could anyone possibly look at these statistics and not call Distaso a blatant liar. 

Now to deal with the question of whether Conner could have floated to where he was found from the North.  No he could not have.  The water level simply wasn't high enough on April 13, 2003.  But for those who insist on believe People's 100 depicts the Conner Site as it looked on April 13, 2003, in spite of the abundance of evidence that it does not, this information should disabuse you of the notion that Conner could have washed or floated from the North to his resting place.  Yes, that's right.  Even in tides as high as 6.39, he would not have washed or floated from the North. It just could not happen.

I made a Field Trip to the Conner Site in August 2009 with a couple of friends.  We wanted to see what happens to debris lines as the tide gets higher and higher during a spring tide -- if heavier/larger objects would stay with the lighter/smaller objects.  And we also wanted to see if objects could wash or float from the North to the South. 

We scheduled the trip at the beginning of a Spring tide.  The tides follow a pattern of increasing daily in height, then decreasing daily in height.  Spring tides are when the gravitational pull is the highest and thus the tides reach their highest levels.  Our plan was to visit the Site, lay down some debris among and in front of the rocks in the breakwater, stay until the debris line had formed, and then return the next day to photograph the debris line, as we had other sites to visit and it would be quite late before the water receded enough for us to photograph the debris line.  The high tide on the 15th peaked at 6.47 feet, above the 6.39 high tide depicted in People's 100.

Here are the debris lines we observed on those days. 
12th -- we found this debris line already in place.  Tide peaked at 6.033. 
13th -- debris line formed from all of the seaweed from the 12th plus the objects we laid down.  Tide peaked at 6.132.  It formed a continuous line, with large/heavy objects right in with the small/light objects.  
We placed a big stick to mark approximate location Conner rested, and measured the distance to the debris line to be 28".

14th -- tide peaked at 6.26.  Debris line reached the Conner marker.  Large/heavy and small/light debris form one continuous line.   

15th -- tide peaked at 6.47, and debris line was North of the path, along the ridge that separates the North from the South. 
It seems obvious to me that none of this debris washed or floated in from the North.