When I have a kid, I want to put him in one of those strollers for twins, then run around the mall looking frantic. ~Steven Wright
Twin ~ from the German twine meaning two together. Gemellology ~ the study of twins.
Theo & Dino, our monogyzetic twins ~ meaning they started life as one egg that had a difference of opinion early on. These are the rarest of the usual twin pairings & though most people refer to them as *identical twins* the term is misleading. Yes, they experience nearly identical brain wave patterns, & share the same DNA, & blood group but they have different fingerprints, different personalities & slightly different body build. There is a scientific basis for these differences ~ all to do with how the egg deals with the mother's DNA & far too complicated for a science moron like myself to attempt to explain in layman terms.
My usual bodyweight before menopause was 7 stone [98 pounds] on a 5'5'' frame. I nearly doubled my weight during this pregnancy & was lumbering around at a whopping great 13 1/2 stone! That's a 182 pounds people! I looked & felt like a beached whale or a galleon under full sail ~ & this is why so many twin pregnancies are considered full term at 36 weeks. Very few of us carry our babies past 37 weeks. The pressure on the uterus is just too great. To say nothing of the bladder!
The stats for having identical twins are quite high though the overall rate of twinning has increased dramatically thanks to fertility drugs. However Nigeria has the highest incidence of twinning in the world because they like yams & yams apparently contain an estrogen like follicle stimulating hormone. They also have more identical than fraternal twins, which is unusual. Identicals are rarer than fraternals & not governed by maternal genetics. I don't think China likes yams. They have the lowest twinning rate. The rest of us just put it down to God!
People are fascinated by twins. Shopping with young twins is not advisable. Every stranger you meet will stop you so they can coo & tell you their twin story. I have never been talked to so much in my life & dreaded going out with the boys in tow. A five minute stop could easily turn into 5 hours! When you are breastfeeding this can become messy & distressing.
Why this fascination? I guess most people are intrigued by the 25% percent of twins that *mirror~image*. I mean, how bizarre is that? Even ordinary identicals draw attention & it has it's uses. I well remember a teenaged Theo throwing a brand new shirt to his brother & saying, in all seriousness,"Here. Try this on so I can see how I'll look in it." He did the same thing with haircuts as I recall! But that's only 25%; the rest aren't mirror images of each other & twinning is remarkably even~handed falling pretty neatly into 1/3 identicals, 2/3 fraternal & of those parings 1/2 of all identicals will be boys & the others will be girls. Fraternal twinning neatly divides into 1/3 boy/boy pairings, 1/3 girl/girl pairings & 1/3 boy/girl pairings.
There is plenty of weird stuff about twins & that's before you get into all the stuff everyone has heard about of twins separated at birth! There's the *vanishing twin*. We've actually experienced this one. Our oldest was a twin too but the developing embryo died very early on in utero & was reabsorbed into my body. This is actually not all that uncommon. The rate of fertilized twins is much higher than the actual birth rate would indicate but the majority leave almost no trace of ever having existed.
Then up to 22% of twins are lefties. That's more than double the general population. Or the bizarre fact they aren't always even born on the same day. Think midnight, people, though the longest gap was a whopping 85 days! Oh, & don't forget the really strange ones when different fathers fertilize different eggs. I find this one strange beyond belief because a woman's body actually welcomes the sperm of a long term partner over that of a stranger & her body will often *attack* foreign sperm. I'm sure it's more complicated than that or this phenomenon would never occur. Just the same...
Then there is the ideoglossia ~ the *secret language* of twins. Yep, we did this one too ~ & the boys taught it to Liddy. English is actually a 2nd language for Liddy. Personally I think it is probably a combination of littlies mispronouncing words & truncating their language. Lots of nouns & verbs, some adjectives but very little of anything else.
So we have: Fraternal twins
& identical twins...
& mirror image twins.
There are also super fecundation ~ that's when two ova from the same cycle are fertilized at different times.
There is mixed chromosome twinning~ when identical boys are conceived but one twin *loses* his Y chromosome resulting in a boy/girl pairing. The girl will always have Turner Syndrome.
There are co~joined twins & parasitic twins. Parasitic are beyond the realms of the weird & wonderful into the truly bizarre.
And my favourite ~ when an egg splits early & then gets fertilized separately! This can result in opposite sex pairings who share 75% of their DNA ~ lots more than fraternal twins usually do & can look very alike.
Elvis & Liberace were both twins but I am in good company. Shakespeare fathered twins ~ Hamnet & Judith. Even way back then artists chose strange names for their children. What sort of a name is Hamnet? Sadly he died young & by the 2nd generation Shakespeare's line had died out ~ but that is another post entirely.