Although it would exist, I think it's very difficult to see on an ultrasound at only 6 weeks? I have no personal experience with this, but I know most of the internet sites I've read so far say that six-week ultrasounds don't show the placenta well because it's too small.
The spelling and grammar errors do lead me to be a bit suspicious of the findings, but medical know-how and ability to speak English well are not necessarily related - it's clearly not peer-reviewed or someone would have fixed the poor fellow's grammar, but that doesn't necessarily mean it's inaccurate either.
To be honest, and here's where I show my bias, the thing that makes me the most suspicious is that this study is from out of High Level, Alberta. That is a small, horrible town. It has very little to recommend it, and it is a total backwater. I have a strong bias against that town, having worked out of it more than once. I have a hard time believing that any new finding of value could come out of that town. But that is a completely ridiculous reason to distrust it, and I know it. Especially because my observations of that town lead me to believe that probably the doctors there get to deal with more pregnancies than almost anything else (except perhaps alcoholism, but most people don't go to the hospital for that). I really can't get past the town . . . I hate knowing I'm prejudiced, and knowing it's unfair, and being unable to keep it from seeping into my consciousness.
It's an interesting idea, and not completely impossible . . . our bodies are not perfectly symmetrical, and it is the baby's genetic code that determines placental growth - it's conceivable that there is some chemical or other difference between the two sides of a uterus, and that Y chromosomes could have a gene that encourages or discourages attachment in those differing conditions. It doesn't sound overly likely to me, but that's no basis for judging science.
I read the methods and results (after the incredibly long and irrelevant front matter), and it looks pretty clear-cut. But it also looks sloppy - the main results table has an error, where the "male-right" table and the "female-left" table both are labeled "right" throughout - neither one is labeled left. It's funny, I have a husband who makes lots of spelling and grammar errors and sometimes substitutes words, and I know he does it even when he knows exactly what he's talking about, but the inability of the author to find someone to proofread his stuff makes me think he isn't all that careful.
I love the idea of us asking our u/s technicians which side the placenta is looking like it's on, and then seeing if it lines up with our baby's sexes! Ooh, citizen science!
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