In which position does the baby lie inside the uterus?

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Discussion Overview

The discussion revolves around the various positions a fetus can occupy inside the uterus during pregnancy, including the implications of these positions for birth and development. Participants explore different fetal orientations, their changes over time, and the impact of gravity on these positions.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants suggest that both the images presented in the discussion can be correct, as the fetus can rotate and adopt various positions.
  • Others note that babies can be in multiple positions, including breech and posterior, during birth, with some sharing personal experiences of their own births.
  • It is mentioned that at term, fetuses typically adopt one of several common positions, with left and right occipitoanterior being the most frequent.
  • Several participants highlight the fetus's ability to change orientation multiple times during development, raising questions about the necessity of these movements for normal development.
  • There are references to studies on fetal development under microgravity conditions, suggesting that gravity may influence fetal orientation and development.
  • Some participants express caution regarding the extrapolation of bioreactor studies to real gravitational effects, emphasizing the complexity of environmental influences on development.
  • Humorous anecdotes about space travel and the challenges of microgravity are shared, illustrating the less glamorous aspects of scientific research in space.

Areas of Agreement / Disagreement

Participants generally agree that fetuses can occupy multiple positions and change orientation during development. However, there are competing views regarding the implications of these movements and the role of gravity, leading to an unresolved discussion on the necessity and impact of fetal orientation.

Contextual Notes

Limitations include the lack of consensus on the necessity of fetal movements for development and the challenges in separating the effects of gravity from other environmental factors in studies.

sameeralord
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Hello everyone,

But I watched a video on youtube that showed another way.That video suggested a pic like this
19681_10489_5.jpg


Is the top pic wrong and my final pic right! Thanks! :smile:
 
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The foetus/baby has it's head facing down but can rotate from side to side as I understand. So both pictures are correct.
 
Babies can be in many different positions even when entering the birth canal. They can be feet first (breech). Most babies are born face down, but my oldest was born face up (posterior) and almost drowned on the amniotic fluid, she was in intensive care for the first 24 hours and I couldn't even see her.
 
That poster is only a representation of one of the more common lies in a term pregnancy.

Pre-term they can be almost any position at all, but at term, space dictates they bring themselves into one of 18 lies with left occipitoanterior (your poster) and right occipitoanterior being most common and demonstrated in perhaps 70% of term pregnancies.
 
sameeralord said:
Hello everyone,

I'm confused about this. This pic shows like this

Something interesting, is that the fetus will change their orientation (with respect to gravity) several specific times during development.

http://www.ncbi.nlm.nih.gov/pubmed/7875103

It's not clear if fetal motion/orientation is required for normal development, but it would be very interesting if it was.
 
Andy Resnick said:
Something interesting, is that the fetus will change their orientation (with respect to gravity) several specific times during development.

http://www.ncbi.nlm.nih.gov/pubmed/7875103

It's not clear if fetal motion/orientation is required for normal development, but it would be very interesting if it was.

There has been work to investigate development under microgravity conditions which have shown that there is a difference
http://www.ncbi.nlm.nih.gov/pubmed/20946105
As well as studies showing altered gene expression in stem cells
http://www.ncbi.nlm.nih.gov/pubmed/20528675

Considering the sensitivity of cell behaviour to environmental conditions it would not surprise me that orientation with respect to gravity was a large factor in development.
 
Andy Resnick said:
Something interesting, is that the fetus will change their orientation (with respect to gravity) several specific times during development.

Gravity has a huge impact. Women carrying babies in a breech or transverse lie are often advised to go swimming as the weightlessness can often stimulate baby to finally move into a position more conductive to vaginal delivery.
 
tanyaeasley said:
Gravity has a huge impact. Women carrying babies in a breech or transverse lie are often advised to go swimming as the weightlessness can often stimulate baby to finally move into a position more conductive to vaginal delivery.

True! (Wife is a doula. Has seen this happen.)
 
Andy Resnick said:
Something interesting, is that the fetus will change their orientation (with respect to gravity) several specific times during development.

And the feeling of a fetus somersaulting in an already tight belly is outside of anything I had ever experienced .

From direct experience, my answer to "In which position does the baby lie inside the uterus?"

"All of them."
 
  • #10
lisab said:
And the feeling of a fetus somersaulting in an already tight belly is outside of anything I had ever experienced .

From direct experience, my answer to "In which position does the baby lie inside the uterus?"

"All of them."
Yeah, you go to bed with your belly sticking out in one direction and you get up and it's in a completely different shape.
 
  • #11
ryan_m_b said:
There has been work to investigate development under microgravity conditions which have shown that there is a difference <snip>

Considering the sensitivity of cell behaviour to environmental conditions it would not surprise me that orientation with respect to gravity was a large factor in development.

tanyaeasley said:
Gravity has a huge impact. Women carrying babies in a breech or transverse lie are often advised to go swimming as the weightlessness can often stimulate baby to finally move into a position more conductive to vaginal delivery.

ryan_m_b's response was more along my line of thought. Clearly gravity has an impact on gross movement, but what is interesting (from my perspective) is the role of mechanosensation in organ/organism development. Bones, in particular, remodel themselves extensively in response to external body forces. The inner ear (otoliths, for example) has a lot of interaction with gravity as well. Finally, the lungs and sinus cavity develops mucus transport *out*- that is, a particular direction is selected. To me, it's striking that the (human) fetus undergoes abrupt changes in orientation around 5 weeks, 18 weeks, and 22 weeks (IIRC- I can't find a single useful reference...) that may coincide with certain embryonic developmental checkpoints.

That said, one should be very careful about extrapolating bioreactor studies to true gravitational effects. In particular, bioreactors still have a lot of fluid shear stress impacting the cells which is difficult to separate out from reduced gravity experiments carried out on the shuttle or ISS.
 
  • #12
Andy Resnick said:
That said, one should be very careful about extrapolating bioreactor studies to true gravitational effects. In particular, bioreactors still have a lot of fluid shear stress impacting the cells which is difficult to separate out from reduced gravity experiments carried out on the shuttle or ISS.

Definitely, I feel that the naming of certain bioreactors as "microgravity simulating" is a huge misnomer. I heard a while ago that squids have been sent to the ISS, I wonder if they are looking at development.
 
  • #13
ryan_m_b said:
I heard a while ago that squids have been sent to the ISS, I wonder if they are looking at development.

Well, with all those arms they could assemble a CO2 scrubber in about 30 seconds...
 
  • #14
ryan_m_b said:
Definitely, I feel that the naming of certain bioreactors as "microgravity simulating" is a huge misnomer. I heard a while ago that squids have been sent to the ISS, I wonder if they are looking at development.

http://mad-as-a-marine-biologist.tumblr.com/post/5897432457/spacesquid

Usually they are looking at embryo development (or single-cell issues)- here's C. elegans:

http://www.space.com/6938-worms-space-study-microgravity.html

Insects have flown, bacteria flown *outside* the shuttle to examine radiation-damage issues. A good story- mice were flown recently, but they all died from hypothermia on orbit- when they peed, the urine soaked into their fur rather than what normally happens. A colleague spent a year devising a urine collection system for the follow-on experiment... not as glamorous as working on the space toilet, but there you go.
 
  • #15
Andy Resnick said:
... not as glamorous as working on the space toilet, but there you go.
Certainly not glamorous if you get a "teeny tiny error" resulting in "Classified Materials Turbulence"... :biggrin:
 
  • #16
DaveC426913 said:
Certainly not glamorous if you get a "teeny tiny error" resulting in "Classified Materials Turbulence"... :biggrin:

Once I was down at JSC and got a tour of the facility, including the space toilet trainer unit. The trainer unit has a camera that points *up*, tied into a (hopefully) closed-circuit TV channel so the astronaut can verify that they are "centered and sealed". It's a standing joke that if the crewperson is a jerk, the video will be leaked to the public.

Naturally, of the whole tour, the space potty was the star attraction. :)
 
  • #17
Andy Resnick said:
not as glamorous as working on the ...ething that's glossed over in a lot of Sci-fi
 
  • #18
Thanks for everyone who replied :smile:
 

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