Sometime in the second trimester, my OB told me that I had to stop sleeping on my back. This was a major concern to me since that is the only way I slept pre-pregnancy and I hated the idea of my sleep being even more disturbed. Her explanation was short, that the weight of the baby, uterus and all that fluid could cut off the blood supply to me and the baby. Sufficiently scared, I went home and did some research just to get a better understanding.
One of your body’s biggest veins, the Inferior Vena Cava, transports the blood back to your heart from essentially every part of your body below your chest. And it runs just beneath the uterus. When your baby gets bigger, laying flat on your back can cause that vein to be collapsed under the weight of the uterus, which means that the blood doesn’t get back to your heart, so less blood is able to be pumped and you and your baby are both without the amount of blood you need to function.
Despite my doctor’s warnings, everyone was quick to tell me not to worry, and that they slept on their backs their whole pregnancy without consequences. I felt somewhat reassured, but made every effort to sleep on my sides, occasionally waking up on my back out of habit. But last night I got a really great eye opener about how serious this is.
At about 2am I woke up from a dead sleep and I knew immediately that something was wrong.
I was on my back, which happens from time to time, but everything felt…well, terrible. I was really hot, but also had this weird clammy feeling, I had clearly already been sweating. I was extremely nauseous even though my stomach didn’t really hurt like anything was wrong, my heart was racing, I was short of breath and I was about as dizzy as I’d ever been. I sat up in bed and within a few minutes, it all got better, though the headache that followed was a real treat. It took me a few minutes to put the pieces together.
It seems that I had done exactly what my doctor warned me about. I had every classic symptom of supine hypotensive syndrome (note that on wikipedia they list slow heartbeat not rapid, but it turns out that it starts with a rapid one and progresses to a slow one. Which means I probably noticed it early.) And in case you wondered, it was absolutely awful, but there was also something comforting about it.
On the one hand, the experience was nothing short of terrifying. Waking up and knowing something is wrong, but not knowing what is an awful, helpless feeling. But on the other, my body did exactly what it was supposed to do. It woke me up, got me to change positions before more serious damage could be done.
Today and all night the baby happily kicked away, reminding me that all was as it should be. But you can bet that I’ll be making a renewed effort to stay on my sides. I’d rather have hip pain every day for the rest of my life than a repeat performance of last night, no question.