# How does surrogate pregnancy make a fetus different than with biological mother? **URL:** \ **Category:** Factual Questions\ **Created:** [February 11, 2021, 1:55am UTC](https://boards.straightdope.com/t/how-does-surrogate-pregnancy-make-a-fetus-different-than-with-biological-mother/932651 "2021-02-11T01:55:24Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Velocity](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/velocity/32/18006_2.png) [@Velocity](https://boards.straightdope.com/u/Velocity)\ **Post date:** [February 11, 2021, 1:55am UTC](https://boards.straightdope.com/t/how-does-surrogate-pregnancy-make-a-fetus-different-than-with-biological-mother/932651/1 "2021-02-11T01:55:24Z")
Suppose you have a couple - Mr. and Mrs. Smith - and then due to various issues, they need a woman to do the surrogate pregnancy on their behalf instead (we’ll call the surrogate Ms. Doe.) The zygote that gets implanted in Doe’s uterus would be the Smith’s - and so would only ever have Smith DNA in it - but in which ways would Doe’s body cause the fetus to develop differently than if it had been in Mrs. Smith’s uterus for those nine months? Presumably, a pregnant woman is putting a lot of her hormones into the fetus, or otherwise imprinting the fetus biologically in some way that would be different than had the fetus been inhabiting some other woman’s uterus all that time. (Things like diet, lifestyle habits, the mother’s health or other attributes might affect it). How would this baby turn out differently by being incubated in Woman A’s uterus vs. in Woman B’s uterus? ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [February 11, 2021, 2:17am UTC](https://boards.straightdope.com/t/how-does-surrogate-pregnancy-make-a-fetus-different-than-with-biological-mother/932651/2 "2021-02-11T02:17:04Z")
Do you have evidence that it does? ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [February 11, 2021, 6:12am UTC](https://boards.straightdope.com/t/how-does-surrogate-pregnancy-make-a-fetus-different-than-with-biological-mother/932651/3 "2021-02-11T06:12:19Z")
> [@Velocity](#): > > How would this baby turn out differently by being incubated in Woman A’s uterus vs. in Woman B’s uterus? For a start, the provable differences: chimeric cells in the child, derived from the mother, and the short term effect of maternal immunity. The other differences – epigenetics, hologenome effects, Lamarckian inheritance etc, aren’t disproved, but are difficult to prove. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [February 11, 2021, 8:23am UTC](https://boards.straightdope.com/t/how-does-surrogate-pregnancy-make-a-fetus-different-than-with-biological-mother/932651/4 "2021-02-11T08:23:16Z")
> [@Melbourne](#): > > but are difficult to prove. Doesn’t seem so hard. Use IFV, induce twinning via embryo bisection, then implant one in the original mother and the other in a surrogate. Repeat a hundred times and see what happens. Ok, maybe not _one hundred_ percent ethical, but doable in principle. ---
**Author:** ![DemonTree](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/demontree/32/8646_2.png) [@DemonTree](https://boards.straightdope.com/u/DemonTree)\ **Post date:** [February 11, 2021, 8:31am UTC](https://boards.straightdope.com/t/how-does-surrogate-pregnancy-make-a-fetus-different-than-with-biological-mother/932651/5 "2021-02-11T08:31:03Z")
If the surrogate mother has already been pregnant with boys and the baby is a boy, he may be more likely to be gay: > **[Fraternal birth order and male sexual orientation](https://en.m.wikipedia.org/wiki/Fraternal_birth_order_and_male_sexual_orientation)** > > Pages for logged out editors learn more > > Fraternal birth order has been correlated with male sexual orientation, with a significant volume of research finding that the more older brothers a male has from the same mother, the greater the probability he will have a homosexual orientation. Ray Blanchard and Anthony Bogaert first identified the association in the 1990s and named it the fraternal birth order effect. Scientists have attributed the effect to a prenatal biological mechanism, sin... There’s also the effects of diet and whatever else the mother is exposed to while pregnant: > **[Course Hero](https://www.coursehero.com/study-guides/boundless-psychology/prenatal-development/)** ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [February 11, 2021, 10:13am UTC](https://boards.straightdope.com/t/how-does-surrogate-pregnancy-make-a-fetus-different-than-with-biological-mother/932651/6 "2021-02-11T10:13:37Z")
> [@Dr.Strangelove](#): > > Doesn’t seem so hard. Use IFV, induce twinning via embryo bisection, then implant one in the original mother and the other in a surrogate. Repeat a hundred times and see what happens. > > Ok, maybe not _one hundred_ percent ethical, but doable in principle. If you use the same two mothers all 100 times, you only need two consent forms and you’re good. ---
**Author:** ![FlikTheBlue](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fliktheblue/32/10972_2.png) [@FlikTheBlue](https://boards.straightdope.com/u/FlikTheBlue)\ **Post date:** [February 11, 2021, 12:48pm UTC](https://boards.straightdope.com/t/how-does-surrogate-pregnancy-make-a-fetus-different-than-with-biological-mother/932651/7 "2021-02-11T12:48:25Z")
> [@Velocity](#): > > Presumably, a pregnant woman is putting a lot of her hormones into the fetus, or otherwise imprinting the fetus biologically in some way that would be different than had the fetus been inhabiting some other woman’s uterus all that time. (Things like diet, lifestyle habits, the mother’s health or other attributes might affect it). How would this baby turn out differently by being incubated in Woman A’s uterus vs. in Woman B’s uterus? Those things will of course have some contribution. As one extreme example, fetal alcohol syndrome or other drug use would of course have an impact. But in general, with two women with otherwise similar lifestyles, diet, exercise regimen, toxic exposures, medical history including exposures to viruses, etc., there isn’t any evidence to point to specific different outcomes that one would expect. ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [February 11, 2021, 1:38pm UTC](https://boards.straightdope.com/t/how-does-surrogate-pregnancy-make-a-fetus-different-than-with-biological-mother/932651/8 "2021-02-11T13:38:00Z")
> [@Riemann](#): > > If you use the same two mothers all 100 times, … You do realize how long that will take, right? 😱 ---
**Author:** ![PoppaSan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/poppasan/32/189_2.png) [@PoppaSan](https://boards.straightdope.com/u/PoppaSan)\ **Post date:** [February 11, 2021, 5:23pm UTC](https://boards.straightdope.com/t/how-does-surrogate-pregnancy-make-a-fetus-different-than-with-biological-mother/932651/9 "2021-02-11T17:23:39Z")
minimum 900 months. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [February 11, 2021, 5:52pm UTC](https://boards.straightdope.com/t/how-does-surrogate-pregnancy-make-a-fetus-different-than-with-biological-mother/932651/10 "2021-02-11T17:52:32Z")
> [@Dr.Strangelove](#): > > Doesn’t seem so hard. Use IFV, induce twinning via embryo bisection, then implant one in the original mother and the other in a surrogate. Repeat a hundred times and see what happens. > > Ok, maybe not _one hundred_ percent ethical, but doable in principle. You could do it using rats. Interesting experiment. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [February 13, 2021, 12:35am UTC](https://boards.straightdope.com/t/how-does-surrogate-pregnancy-make-a-fetus-different-than-with-biological-mother/932651/11 "2021-02-13T00:35:52Z")
> [@Keeve](#): > > You do realize how long that will take, right It’s IVF. That’s the whole point of IVF …