Twins With Different Birthdays

No - I'm not kidding!

Note: I have deliberately anonymised this account to provide a small amount of confidentiality.

Twins run very strongly in my wife's family: she's a twin, and her grandmother was a triplet. So it wasn't such a great surprise when we found out that she was pregnant with twins (not that that made the prospect any less daunting!).

What did turn out to be unusual was the boys' arrival, as they were born 18 days apart. (We didn't know they were going to be boys, but we do now, so I will speak in the knowledge which we din't have at the time.)

How does this happen? Well, first a little twins biology. Everyone knows there are identical or non-identical (fraternal) twins. What many - if not most - people who aren't twins or who don't have twins in their family don't know is the genetics and biology behind the different types of twins.

Firstly, every conception has essentially the same statiscal likelihood of producing identical twins (normalising for age, any fertility drugs, etc). Identical twins occur when a single fertilised egg splits into two to form two foetuses with the same DNA.

Fraternal twins on the other hand, occur when the mother produces more than one egg at a time (exept of course in IVF). This phenomenon is called multiple ovulation, and while it appears to be more common in older mothers, it is an hereditary genetic trait. Accordingly, a woman who carries the gene has a very high chance of producing fraternal twins, as do any daughters she may have. Her sons may carry the gene, but of course they don't produce the eggs, so they can't contribute much to the twin production process. If they have daughters, however, those girls will have a high chance of producing fraternal twins. And so it goes.

So, to our story. Premature arrival in twins is not uncommon; about 36-37 weeks is generally considered full-term. That knowledge provided scant comfort when Twin 1 broke his waters at 29 weeks, as this is clearly well before any version of "full-term" and the baby has not reached a stage of development where health - let alone survival - are assured. (There are risks associated with childbirth for both mother and baby even with modern technology all the way up until full-term, so the fragility of a very early baby cannot be overstated.)

Anyway, off to the hospital we went, with my wife in no state of happiness whatsoever, and me trying to maintain some semblance of calm. We got there and were advised that the doctors would deliver a shot of a steroid to the baby try and delay the arrival for 24 hours in order to allow his lungs to develop so he would have as good a chance as possible of breathing when he came out. They also said he was likely coming early as he wasn't receiving a full supply of blood (and associated oxygen, nutrients, etc).

The doctors said they would have to deliver him by caesarean section the following morning, so next morning arrived and there we were, waiting for the anaesthetists, and for my wife to be wheeled off to the theatre. Various nurses and the like were coming and going well past the time when some sort of action should have started, so we asked what was going on. Next surprise: "oh, the baby is too far advanced, so we're going to have to deliver it naturally." Conceptually that was fine (aside from the obvious concerns about the early arrival), but again it was a bit of a surprise!. Anyway, about an hour later (~10am) we had baby Louis, who popped into the world and gave a squeak, started breathing and off he went, apparently hale and hearty - albeit at 1.1kg very small and fragile.

So we began to wait. We were in the delivery room with about 10 other people: paediatricians, neonatologists, the obstetrician, nurses of varying flavours. And they were all waiting too. Pretty shortly the paediatric team for Louis left, and the crowd was a bit smaller. Then after half an hour or so the team for Twin 2 said "we won't be far away, but we've got other things to do", then eventually the obstetrician said "well if I leave the other one will surely come!" so off he went. Come 7pm however, still pregnant, and now began the seige.

The paediatricians and neonatologists said "well, the first one came out, and he's alright, so let's have the other one out and we can look after it, too." But the obstetrician said "I'm resonsible for this pregnant woman, and the safest place for her baby to be at this stage of the pregnancy is in he belly." Second twins - particularly when born early - often have problems as a result of the first twin initiaing labour and the second one coming when hey aren't ready.

So the hospital brought me a bed in the delivery room, and we (or I) went to sleep. In the morning the obstetrician came back and pronounced that mother is no longer in labour. Accordingly she had to be moved out of the delivery ward to wait somewhere else. This presented a small problem as she was the first person ever in the hospital to qualify for postnatal as well as prenatal! They opted for prenatal as she was still pregnant, but of course she was the only "mother to be" with a baby downstairs!

Hmm. Just looked up the definition of twins:

American Heritage Dictionary - (www.dictionary.reference.com)

twin (twĭn)

n.

1. 1. One of two offspring born at the same birth.

By that definition the boys aren't twins. I remain to be convinced.

Aha! Here's a better one:

The American Heritage Science Dictionary - (www.dictionary.reference.com)

twin (twĭn)

1. 1. One of two offspring born of a single gestation. Identical twins result from the division of a fertilized egg. Fraternal twins result from the fertilization of two separate eggs at the same time.

Makes the first one wrong, really.

Anyway, thus the waiting began for our second baby.

This was a period of high anxiety for all concerned. Our obstetrician - a specialist in multiple pregnancies for over 20 years - had never encountered a case such as this, and neither had anyone else in the hospital. (One nurse seemed to recall having heard of it!) So this was a learning experience for everyone. As we were about to discover, being part of learning experiences for medical professionals and hospital staff is not a pleasant experience (which is not to say that they weren't extremely professional; they absolutely were, in particular the obstetrician, who bore the highest risk exposure in the process of course.) One of the nurses described to us that our file was like a telephone book: every time our obstetrician had seen us he proceeded to consult with a worldwide panel of experts in various medical specialisations, and the results were added to the compendium.

I like to put this situation (the case outside the experience of medical staff involved) in a bit of analytical context. We all live our lives - professional, personal, social, etc - within what statisticians call "bounds of uncertainty". What this means is that we have a pretty high expectation on a day to day and minute to minute basis that anything that may occur will not be entirely unexpected. In a typical statistical analysis there is about a 67% chance that an event will occur within two standard deviations of the mean. This means that if the average egg weighs 50g, two-thirds of all eggs will weigh between say 40 and 60 grams (I'm making these precise numbers up for illustrative purposes).

In our daily lives it means that there is a certain probability that the sun will shine, or that the phone will ring, or that we will bump into Dave, or whatever. Conversely the likelihood of something unexpected happening is generally pretty small. And for the most part, something unexpected happening will usually be manageable anywyay. However when events outside peoples' expectations do occur, they can react very strangely, as most people do not like surprises.

In the medical professional situation all this has a special meaning. If something unexpected happens, that is not good news, as people do not necessarily have the training or procedures in place to respond to a situation, which of course brings with it potentially very dire consequences. (Unlike in almost any other profession: if something unexpected happens and we don't deal with it appropriately, lives are unlikely to be lost!)

Accordingly, medical professionals typically operate within much higher bounds of uncertainty. A doctor wants to have a very high level of confidence that in his average working day he is highly unlikely to see anything he hasn't either seen before, or at the very least been specifically trained to deal with.

The point of this long-winded explanation is that everyone's stress levels in the hospital were extremely high (not just ours!). My wife had her blood pressure and hers and the baby's heart rates monitored every 4 hours for the next 18 days. You can imagine how relaxing that alone was, never mind the fact that there was never more than 4 consecutive hours sleep allowed in any one night! (The sound of your baby's heartbeat goes from being exciting and reassut=ring when heard through the ultrasoud to being monotonous to the point of physical pain when listened to for 10-20 minutes every 4 hours!)

Of course during the time she was in hospital my wife had many visitors, but even this began to develop associated stresses. Everyone was naturally fascinated by the situation, but after being asked the same questions 10 times they began to drag a bit. I actually produced a list of questions with snappy answers headed "please do not enter without first reading the below q&a re: the occupant", which I was prevented from attaching it to the door as it was a bit too snappy for my wife's liking!

Things finally started to relax a little bit after two weeks, but the tension cranked up again on the seventeenth night in hospital when the nurse came to take these results, and it took over an hour of attachment to the monitors and they couldn't get a decent reading. It turned out this was the precursor to the next day's events. I got a call at 7am the next morning to say the baby was on the way.

All was much more relaxed this time, as mother and baby had been being so closely monitored for such an extended period, but of course these things never go smoothly. In the delivery room everything was relaxed and baby was on his way when my wife was given a shot of penicillin. This was the same drug she had been taking for the previous two weeks while in hospital as insurance against infection, but at this critical juncture she had an anaphylactic (allergic) reaction. This means that she was unable to breathe and is quite a serious situation. Baby's heart rate plummeted, and the tension went back up fifteen notches. A shot of adrenaline suppressed my wife's reaction, but the obstetrician said we could wait only a very short while (less than 5 minutes) to see if we could get the baby out naturally, and otherwise he would have to do an emergency caesarean.

This was a defining moment in the story in more ways than one. Baby's life hung in the balance, but that had conceivable been the case for the entire time. What was more interesting to me was our obstetrician's coolness. This was the only time when I was aware that he was under stress, and that only from an intangible reading of the tension in the room, but he went about his business almost without a hint of how serious the situation was.

After a few very short moments with baby's heart rate not changing and him not advancing far enough to start breathing on his own, the caesarean was ordered. Ten minutes later twin 2, Fred, was born at 32 weeks weighing 1.3 kg - hardly a monster, but nearly 20% bigger than his brother.

I met the obstetrician in the neonatal unit a short while later and his greeting was "you owe me more than a drink"!

Louis and Fred are now healthy three year-olds who have suffered no long-term effects of their tumultuous arrival in the world, for which we thank all those involved in the process of their arrival and subsequent care.