MZ twin mamas

[DoomaYula]

The article here says MZ mono/di are the most common. Just curious, what were your twins?

Mine were mono/di.

[Gena 22]

I've heard that too. By a factor of something like: 30ish% are di-di, 60ish% are mono-di, and some rare number are mono-mono.

Makes sense. I think MZ twins can only be di-di if they divide in the first 1-3 days after conception. There's a longer time for mono-di, something like a week. Any division after 13 days or so is mono-mono.

Love the poll, interested to see what our little population has!

[LoisLane]

I vaguely remember reading that if the embryo splits day 0-3, it's di-di, days 4-8 is mono-di, days 9-12 is mo-mo, and after day 13 is conjoined. So those days are pretty evenly divided...

Maybe an embryo that make it to day 9 is just really unlikely to split? Or maybe some of those that split end up being miscarried? Hmmmm...curious!

[Gena 22]

Hmmm. I'd love better numbers on this. I posted as a di-di but I do have my doubts. I KNOW they had separate sacs. My MW had to break Baby B's water over a day after Baby A's broke on it's own.

In favor of di-di:

My peri was certain of it, and he and his office are well respected in our area.

I saw the membrane between the babies at our first u/s (19w). It was pretty thick.

What makes me doubt:

It get harder to tell as the weeks go on, and we only discovered Baby B at 19+ weeks.

At birth only one placenta came out and it sure looked like one all along and not fused. My very experienced MW wasn't sure. No clear answer from her.

My twins were a lb apart at birth - 5.12 and 6.11. That seems like a lot to me. And the weight difference has had lasting effects. The smaller twin has stayed smaller. She eats a lot less, and is very picky. Everything about her is different. I know this is uncool to say or think, but my Baby A is "normal." She's built like me, she acts like me. Baby B is a charming little sprite, charismatic and aloof, with a totally different approach to everything. From day one.

It's like Baby B was deprived a bit in utero and she learned to live differently, in a way that stuck.

How could that happen if they both had their own placentas and equal access to everything? Her cord was fine, I remember seeing that too.

[LoisLane]

Originally Posted by Gena 22

My twins were a lb apart at birth - 5.12 and 6.11. That seems like a lot to me. And the weight difference has had lasting effects. The smaller twin has stayed smaller. She eats a lot less, and is very picky. Everything about her is different. I know this is uncool to say or think, but my Baby A is "normal." She's built like me, she acts like me. Baby B is a charming little sprite, charismatic and aloof, with a totally different approach to everything. From day one.

It's like Baby B was deprived a bit in utero and she learned to live differently, in a way that stuck.

How could that happen if they both had their own placentas and equal access to everything? Her cord was fine, I remember seeing that too.

OT but had to say WHOA! This is *exactly* how it is with my two (MZ, mono-di) and I, too, have never given words to it because it somehow seems, well, weird or wrong or not cool. But with Baby A, well, I completely understand her (her strengths and her weaknesses). We are a lot alike. She makes sense to me even if some of my frustrations come from our similarities. I understand how to motivate and encourage her. I *get* her. But Baby B -- it's like she's been marching to her own polka since Day 1. She constantly surprises me and there are so many ways I just don't understand her at all (although I delight in her completely). She, too, is like a sprite or fairy -- and was almost a pound smaller at birth (had been squished for much of the pregnancy and was born double footling breech extraction) and she has stayed smaller throughout.

Anyone else with otherworldly Twin B's?

[Gena 22]

Otherworldly is just right. She's got the most amazing smile and impish looks, but is very introspective, sometimes surprisingly independent, sometimes needing extra protection.

She too was squeezed up under the monster placenta, and had an extra barrier to the world in utero. Baby A was right there on the outside, listening to and kicking at everything.

Hmmm, Liz. Wonder if the similarities are because of positioning? Or maybe mine were mono-di? Is this true navel-gazing?

[OGirlieMama]

Mine are di-di, which seems to be the least-well-understood format for MZ twins. I've met so many people with di-di MZs who were told that their twins were fraternal while they were still in utero.

My Baby B is totally otherworldly and extra-wacky. She and her sister were only 3 ounces apart at birth, but Katie (B) had more severe RDS and was on a ventilator for almost 2 weeks, and required oxygen for the first 5 months of her life. I usually attribute a lot of her particular traits to that, rather than to anything in utero. But she's definitely the crazier of my very-crazy-in-general girls.

[ShanaV]

Di-di MZ boys here.

I always found it so annoying that when people find out they're in separate sacs that we get "Oh, so they're fraternal!" It became so tiring to have to explain and re-explain ad nauseum that yes, it is possible for identical twins to split into two sacs, have two placentas, etc. We got a cheek swab DNA test done to determine zygosity, and their DNA is a match.

This always makes me think of the Olsen twins, cus they really look alike, yet they say they're fraternal. I really wonder whether they were di-di and people just assumed that meant fraternal. They don't look like just any ol' siblings do, which is DNA-wise what fraternal twins are anyway.

[MamaRabbit]

We were told fraternal with own sacs/placentas at the 12 wk ultrasound.

They came out MZ with their own sacs but shared placenta.

[DoomaYula]

Okay, so my babies switched places before birth -- the baby who was B for 32w became A, and vice versa.

B (who became A) was the donor in the TTTS scenario, so he didn't have as much of the placenta and he is DEFINITELY an otherworldly kid. His brother is fairly "normal," but he totally marches to his own beat and has his own issues that we deal with regularly. He's an interesting kid. In some ways he's easier -- he's much more sensitive and understanding -- and that can also be harder.

[kjoy2]

Originally Posted by Gena 22

My twins were a lb apart at birth - 5.12 and 6.11. That seems like a lot to me. And the weight difference has had lasting effects. The smaller twin has stayed smaller. She eats a lot less, and is very picky. Everything about her is different. I know this is uncool to say or think, but my Baby A is "normal." She's built like me, she acts like me. Baby B is a charming little sprite, charismatic and aloof, with a totally different approach to everything. From day one.

It's like Baby B was deprived a bit in utero and she learned to live differently, in a way that stuck.

How could that happen if they both had their own placentas and equal access to everything? Her cord was fine, I remember seeing that too.

Over here by your definition of 'normal' meaning 'like me'. GENA!!!!

My mono/di twins are completely different. Completely. They fight all the time b/c of it. The one that was smaller at birth by only a few ounces (who started as B but ended as A) is also more sensitive, more picky about everything. But IMO, that has much more to do with their innate personalities & their souls than it does with in-utero environment. Perhaps I'd feel differently had their been a severe case of TTTS or other cord issue or premature birth, who knows. In the end, it's an interesting case study in what forms a personality - DNA vs nature (interpreted more loosely here than strictly DNA) vs nurture. And as we should remember, even mono twins do not have the exact same DNA expressions.

[Gena 22]

I know that is bad to say, normal = like me. In some ways I mean it, in others I use it as short hand.

Guess I'm fascinated by the idea that "identical" twins can have different inborn personalities. So personality isn't exactly genetic - it's not in the DNA totally. And it's not post birth environment - our twins were different from day one. So where does that leave us? Who we are is because of the placement of the placenta and cord?

Yes, this is a chance to get all metaphysical, but I'd like a physical explanation too. Hmmm. One of those great mysteries.

[MamaRabbit]

In Having Twins by Elizabeth Davis, I remember reading her explanation for identicals never actually being truly identical. When the egg splits, it's the fragmental (mitochodrial?) DNA that is different and accounts for the slight differences.

[kjoy2]

Gena, we have souls. The universe sent you monozygotic twins to help you come to grips with this great mystery. Then it introduced you to me so that I could gently prod you into belief.

PS. Julian gently suggests you look at yourself and ask what you are and why. We just love you, darling.

[tink79]

di/di but the placentas were fused together. We were in the category of people told that they were fraternal because they were di/di, but they are identical. We had the dna test but we could have just saved our money and waited because there was no question after the first year, our baby B caught up and their features filled out.

[Gena 22]

Thank you for always setting me straight, momma!

[ChaoticMum]

Originally Posted by Gena 22

How could that happen if they both had their own placentas and equal access to everything? Her cord was fine, I remember seeing that too.

But you can never tell if they had equal access. One placenta may have been bigger, one cord may have been inserted just slightly more 'perfectly' etc etc. This can happen with mono/di's also - the cords may not be inserted so they share the placenta 'perfectly even' - this could account for one getting slightly less nourishment - not enough to be detrimental, but enough to change the way the brain grew. Etc etc etc etc

There are Sooooooooooooo many variables and then when you throw in the mitochondrial DNA that was mentioned it adds even more variables.

That being said, my mono/di Baby B is also my more impish and just seems to 'get things' slightly quicker. He was also the one that was crammed in while his brother seemed to stretch out, take what room he wanted etc. He was also the one who was more 'out there' with B being tucked up under the placenta which was fundally placed.

[nd_deadhead]

My mono/di twins are 16 years old. They were born at 39 weeks, weighing 7-14 and 8-0 pounds. They were a lot alike, and were on almost exactly the same schedule - right down to having poopy diapers at the same time - about every 5 days!

But as they grew, their personalities changed. While they were more alike than different for a long time, we could see that they approached things from different directions. B has always jumped in headfirst; J was more clingy, more likely to watch and see how things went for his brother before jumping in.

That difference becomes greater as they get older.