An interesting observation: A note on taking research with a grain of salt

I thought this sub might be interested in something I found just now. I was interested to know if there was a correlation between fetal activity in the womb and baby/toddler activity. For instance, if a baby kicks all the time in the womb, are they a little hellion bouncing off the walls later (like my almost one-year-old)?

I didn't find any articles to answer this question (if you have it, please share!), but I did stumble upon this one (Sex differences in fetal activity and childhood hyperactivity).

From the abstract:

Background: Most studies have failed to identify significant sex differences in movement (or activity) during fetal development. However, the sample sizes and lengths of time fetuses were monitored in these studies have been limited.

Aim and methods: Using the recollections provided by a sample of 6,546 mothers, this study examines variations in fetal activity levels for every month of pregnancy. Evidence was also sought that fetal activity might be associated with hyperactivity/ hyperkinesis following birth. (I'm adding some more methodology: they asked mothers 20 years later to recall activity).

Results: By the fourth month of pregnancy, mothers reported that males were significantly more active in the womb than females. Also, fetal activity was positively correlated with hyperactivity following birth, especially for males.

Conclusion: Despite numerous prior studies derived from small samples failing to reveal significant sex differences in fetal activity, the present study demonstrates that males are about 10% more active than females during the latter two-thirds of pregnancy and are even more so following birth. Furthermore, even within each gender, fetal activity predicted hyperactivity in childhood, thus indicating that there must be a common biological root for variations in activity levels.

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Why is this interesting to me, aside from the shakiness of asking for recollections 20 years after the fact? Because other researchers (Karraker, Vogel, & Lake, 1995; Provenzano, & Luria, 1974) have found that parents tend to describe their own newborn baby girls and baby boys differently, including describing boys as more active.

Notice the final line of the conclusion in the abstract, "thus indicating that there must be a common biological root for variations in activity levels." MUST?! Nope. This is just bad scientific writing.

So I share this as an interesting stumbleupon and a quick reminder to think critically about the research you intake, including peer-reviewed research from good journals.

PS How would YOU have tagged this post?
 
@dundermifflinfarmer I think the only way to measure this would be surveying mothers who don't know the gender while pregnant.

I think it's probably completely gender bias in this survey, in my uneducated (no science or statistics degree) opinion.
 
@basilstaghare Still wouldn't account for variables such as position of placenta. Anterior placenta can affect how much movement felt by Mum.

Agree its just bad science with a heaping of gender bias
 
@4rwyn True, but unless there is a correlation between placenta position and sex this should be averaged out by a large enough sample size
 
@4rwyn Great point! I had an anterior placenta with my son so he felt very mellow...but I'm not sure if he really was or I just couldn't feel much.
 
@andrew36 Same here! Though my son as a baby is way more mellow than either of his sisters were, so maybe he was more chill before he was born, too. I will never know.
 
@basilstaghare I didn’t find out the gender while pregnant. This was my first pregnancy and I’m 7 months postpartum. I have no idea how I would describe my son’s activity level in utero because I have nothing to compare it to! I might have said he was highly active in utero, but my next pregnancy might give me a taste of what high activity actually feels like and I would change my mind. And of course, at that point, it’s likely so much time will have gone by that I will be misremembering my first pregnancy completely. It’s just such a difficult thing to gauge based on someone’s personal recollection!
 
@dundermifflinfarmer Really good post. This sub or just people can be almost a bit too reliant on finding any scientific article that backs their current view.... without critically analyzing the methodology, sample size, and definitions.

Even science (or should I say especially science) shouldn't be taken at face value, and should be open to valid critique.
 
@catherinenosleep Aw, thank you! And I totally agree. But it's not their fault, the way we teach science is inherently flawed. We tend not to leave room for ambiguity or change. Although to be fair, that does make it really hard to teach. I teach psych courses and it's difficult to stress that what I'm teaching is what the evidence points to right now and that they should still be critical, while maintaining their respect for the field and helping them learn the info well enough to pass the class. It's a tricky balance.
 
@catherinenosleep I think I am guilty of this. The problem is that if I was going to write an article or really look into something, it would take me several hours if not days to gather all the material I could, read it, evaluate it, etc.

A reddit post doesn't have that kind of time frame. If you waited days to respond to a reddit post, you'd never find it again, and nobody will ever see your reply to refute it, etc. Social media moves fast.

When I do respond on this sub I try to avoid commenting on topics I don't really know much about. If I do know about it, then it probably means that I have read studies, articles, or accumulated background knowledge in some other way, but I can't easily verify all of that long history in a single post. So if someone asks for a source, then I might google and select something that looks like it backs up what I'm saying. Which I know is bad practice. But I don't really know how else to do it on social media - if there is a public facing expert that I broadly trust, then I will tend to go looking for their material first, rather than just grabbing a random study. But I can't always remember where or how I learned something, and often it's from multiple sources anyway.
 
@cutin No yeah for sure. I understand, agree, and I am guilty of the same. There is definitely a balance....overly cautious will result in less discussion and sharing of ideas, which are really important and why this sub exists as well. And also the idea is that if you, or I, or anyone shares something...yeah we may not have a ton of time to thoroughly vet it, but someone else might and they can comment and share. And if everyone is open to ideas and thinks critically we will hopefully get to a better conclusion backed by sciencem
 
@catherinenosleep This is because science literacy is not great because it's hard to teach objective thinking when society is mostly ego driven. People like to find things that resonate with assumptions and bias they already hold. This leads to people using science like legal arguments to support points rather than a collection of observations that describe everything around us.
 
@dundermifflinfarmer All good points, but also… what are those mothers using as baseline reference for “normal” movement? I’ve had two kids, both of which felt - to me - to be very active in utero. My first is a hyper 4yo, my second is a sleepy newborn. I have no way of telling whether they were any more or less active in utero than the “average” fetus, because I only have those two experiences for reference.
 
@katrina2017 This is exactly how I feel. And yes, doctors did comment at scans "Wow, this baby is so active!" but probably they say that to everyone. My third was so wriggly he flipped from breech to back again at 37 weeks. But I don't know if he was unusually active. Maybe my womb was just unusually loose XD

It feels like a common comment is "My baby kicks me so much I wonder if he/she will be a footballer!"
 
@dundermifflinfarmer But active children who are boys are also tolerated as normal for their gender.
Meanwhile active children who are girls are percieved negatively as a reflection on the parents and parents are under pressure to calm them down.

There's heaps of research (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7002030/ for starters) that parents generally influence gender stereotypes. I would expect that unless exceptional parents recollection (!!) would be based on retroactive gender stereotypes as well.
 
@dundermifflinfarmer I'm only 7 months postpartum, and I couldn't tell you how active this baby was in utero, much less how active my 3 year old was in comparison. They're different genders, but the differences in pregnancies were minimal.
 
@fvp It's a stupid methodology. Although I can say, at 11 months pp, my baby was hella active in utero. Moving all day every day. I had constant motion sickness from her never-ending movement.
 
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