A little about Twin to Twin Transfusion Syndrome

During that last week at work I was rushing to get tasks ticked off my list but I grew increasingly uncomfortable. I really hoped I was just being a first time mother hypochondriac and that it wasn't anything serious. I asked pregnant friends if they ever felt tight across their tummy. I even rang the midwives for a chat, but I guess I played it down, describing my symptoms but not mentioning just how scared I felt.

I wasn't really sleeping at night. I struggled to find a comfortable position. Sitting up in the car or at my desk was awful, it caused a continuous dull ache below my bump. One day I remember realising that the babies movement seemed to be weaker. I lay down on the (dirty) carpet under my desk and felt reassured when I felt stronger kicks against the pressure of the floor.

There was of course a scary possibility at the back of my mind. It had been there nearly the whole pregnancy. We found out very early on, at about 6 weeks, that we were expecting twins. We had sat basically speechless while my obstetrician showed us those two tiny babies and their heartbeats. I had asked him if he was joking, whilst Rob wanted reassurance there were only two! A couple of weeks later my Doctor shared another piece of news; the babies were sharing a placenta, confirming I was carrying identical twins. I asked him if this brought any added risks. He admitted that yes, one condition could develop, twin to twin transfusion syndrome (TTTS), but only about 15% of monochorionic (shared placenta) twin pregnancies developed TTTS. My Doctor reassured us that he would keep an eye on the babies frequently via ultrasound to ensure if it happened it was caught early, but not to worry too much as there were treatments.

That weekend I made the mistake of googling TTTS, and immediately wished I hadn't. I felt sick enough as it was with morning sickness, but reading about the possible outcomes of TTTS made me feel even worse. 

I quote wikipedia "As a result of sharing a single placenta, the blood supplies of monochorionic twins can become connected, so that they share blood circulation; although each foetus uses it's own portion of the placenta, the connecting blood vessels within the placenta allow blood to pass from one twin to the other. The blood can be transferred disproportionately from one twin (the donor) to the other (the recipient). The transfusion causes the donor twin to have decreased blood volume, retarding it's development and growth, and also decreased urinary output, leading to a lower than normal level of amniotic fluid. The blood volume of the recipient twin is increased which can strain the foetus' heart and eventually lead to heart failure. The recipient twin has a higher than normal urinary output, which leads to excess amniotic fluid. In early pregnancy (before 26 weeks) TTTS can cause both foetus' to die or lead to severe disabilities. The cause of TTTS is not known."

We tried not to dwell on the possibility of TTTS, but we approached each ultrasound with as much dread as excitement. With each good scan Rob and I relaxed a little. So as I grew increasingly uncomfortable during that week my vain hope that the babies had just gone through a growth spurt was fading. In hindsight I wish I had gone to the Doctor earlier, but I doubt this would have changed the outcome at all. I had no idea that within a week we would be parents.

A photo from the 12 week scan, showing the two babies. The diagonal line is the membranes of their separate amniotic sacs.