there are rare and unusual types of twins that exist beyond the standard
identical and fraternal twins that we all know and love. after hearing about a
few of these rare types of twins I was so fascinated that I dove into the
depths of the Internet to learn about various different types of twins
I am basically a PhD at this point on twin studies so rather than keep all of
this useless but cool information to myself I decided to share with y'all
today but before we get into it I have to shamelessly plug my channel please
like and subscribe for more my weekly videos and if you are a current
subscriber thank you so much I really do appreciate you guys before we get into
the rare types of twins I first want to go over the two more common types of
twins identical and fraternal twins and how they form it's important to have
this background information so that you can better understand the rare types of
twins later on in this video first the most common types of twins there are are
fraternal twins. fraternal twins are conceived when the mother drops more
than one egg in a cycle let's say two eggs in this scenario if two eggs get
fertilized by sperm in that cycle it results in fraternal twins fraternal
twins are genetically the same as any other brother-sister relationship they
are just conceived at the same time that's why fraternal twins can look
different from each other they can be boy girl twins because they were
conceived with completely separate eggs and completely separate sperm the next
most common type of twins are identical twins or monozygotic twins meaning they
started from a single zygote identical twins happen when one egg is fertilized
by one sperm and then somehow three miracles and magic the fertilized egg
splits to create two separate people with the same DNA scientists don't even
know what causes the egg to split create identical twins it is completely
random as far as they can tell now that you have gotten my internet phd rundown
of how fraternal and identical twins come into existence let's get into the
fun rare types of twins the first rare type of twin is through
eternal super 2nd ation twins aka twins with different fathers now how
do these types of twins happen you may wonder ok I will not get to sciency
having you guys today the point of this video is to break it down so it's easy
for everyone to understand this is not a research paper by any means I am NOT a
scientist doctor anything smart really I am your fun fact friend the way that
twins with different fathers occur in case any of you just cannot fathom how
this could ever happen is the woman in this scenario would need to drop more
than one egg in her cycle to be able to conceive fraternal twins then said lady
would need to have intercourse with more than one man in her fertile window the
sperm from one man would fertilize one egg the sperm from the second guy third
for I'm not judging here sperm from another guy would then fertilize the
second egg and boom twins that are genetically half siblings this would be
the greatest episode of Maury of all time can you imagine you
the next rare type of twins are conjoined twins conjoined twins happen
in about one and every two hundred thousand live births according to the
University of Maryland conjoined twins are genetically identical twins
literally the only difference between conjoined twins and identical twins is
when the egg splits again identical twins occur when one single fertilized
egg splits and develops into two individuals anywhere from three to
twelve days after conception the embryonic layers will split to form
identical twins according to the Mayo Clinic it's believed that one the embryo
splits later than this usually between thirteen to fifteen days after
conception separation stops before the process is complete and the resulting
twins are conjoined as someone with identical twins myself it's crazy to
think that it's literally just a few days difference in one the egg splits
that creates such a life-altering result an example of conjoined twins that you
may have heard of are Abby and Brittany that had a reality show for a little bit
on TLC the next rare type of twins occur through something called super
meditation aka getting pregnant once you are already pregnant this is very rare
there are only a few documented cases ever of this occurring in order for this
to happen three uncommon things have to take place
first the woman would need to ovulate after she is already pregnant which the
body typically doesn't do when you're pregnant
your body releases hormones that are supposed to prevent further ovulation
next the second egg would need to be fertilized by sperm and last the
fertilized egg would then need to travel and implant itself into an already
pregnant womb a couple examples that I was able to find on health line about
this in 2005 a woman had undergone IVF to become pregnant with twins the doctor
noticed during an ultrasound that she was actually pregnant with triplets the
third fetus was to be three weeks younger than its
siblings the doctors concluded that another fertilization and implantation
took place naturally weeks after the IVF procedure the next case that I found is
in 1999 there was a report of a woman who is believed to have experienced
super fedot ation spontaneously the fetuses were found to be four weeks
apart the woman went through a normal pregnancy with both babies and they were
born healthy then max rare types of twin I'm going to go over I have to first
show you this meme because 99.99% of the time it is a valid meme and it's
hilarious that people even ask this question but the meme is are your boy
girl twins identic but there is actually such thing as boy-girl identical twins
out there so these crazy people who ask parents with boy girl twins if they are
identical they might actually be geniuses probably not though
but maybe maybe we should give him the benefit of the doubt according to health
line identical twins can be different sexes these twins begin as identical
male twins like all males they both have XY chromosomes instead of XX the way
females do very soon after the egg splits into a genetic mutation causes
one twin to lose its Y sex chromosomes changing it to be just X and then
nothing since there is only one x chromosome the female twin has a
condition called Turner syndrome so it is a little bit different than the
traditional girl/boy twins that have the xx and XY sex chromosomes females with
Turner syndrome I mean they are they are females they have the sex organs that
females have they they would just suffer with some other conditions
I would google it if I were you again I'm not a doctor I don't know all the
details of Turner syndromes but that is how you would get boy-girl I done
twins the next rare and unusual type of twins are mirror image twins mirror
image twins aren't necessarily a new category of twins they are identical
twins that have characteristics that mirror each other for example one twin
is left-handed one is right-handed they may have hair whirls or parts on
different sides one may have a unique mole on one side of their face and the
other hazard on the opposite side in extreme cases that are very rare mirror
image twins will display something called situs inversus where internal
organs such as the heart liver lungs stomach are situated on the opposite
anatomical side for one of the twins according to a very well family article
it's theorized that mirror image twinning occurs when the egg splits
later nine to twelve days post conception but not late enough that
conjoined twins form many mirror image twins also display characteristics of
other late splitting monozygotic or identical twins and are also
monochorionic mono amniotic twins in the womb so mono mono twins both share the
same placenta and they are in the same sac so if you aren't pregnant or if you
are a mono mono twin where you shared a sac with your twin there is a chance
that you could be a mirror image twin but there is not an easy way to test to
see if you are a mirror image twin you would just have to figure it out based
on the visual characteristics that you could see that mirror each other or
again in the extreme case where one of the twins has situs inversus that would
be a way to figure it out the next rare type of twin that we're gonna go into
are semi identical twins this occurs when one egg is fertilized by two sperm
before splitting DNA wise these twins would be semi identical because they
would match a hundred percent on the mom side because they started from one egg
but then on the father's side since there were two sperm that fertilized the
egg there would be a mishmash where some of the DNA would
match some of it wouldn't on the father side again I am NOT a doctor or
scientist or anything really that super-smart but from my understanding
the twins depending on each individual scenario and how the egg splits will
share 50 to 100 percent of the paternal DNA and it just is kind of a
free-for-all between what genetic material goes into each resulting embryo
if you enjoyed this video please be sure to let me know in the comments below I
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also be sure to check out the description area below where I will have
link to other videos that I recommend and the links and articles to the
information I found in this video like subscribe share and do all the things
see you in the next video bye