The most dangerous drug in the world: 'Devil's Breath' chemical from Colombia can block free will, wipe memory and even kill. 1  Scopolamine often blown into faces of victims or added to drinks.
To summarize, it appears the best position is left side, followed by right side. After 16 weeks it's best not to sleep on your back, and you probably won't sleep on your stomach. (One way to avoid sleeping on your back is to sew a tennis ball into the back of your pajamas; this works for people who snore, too).
Insomnia During Pregnancy: Snooze or Lose! Insomnia During Pregnancy: Causes and Treatment. You may lose sleep during pregnancy for a variety of reasons. Whatever the reason may be, it is important to understand that insomnia is not harmful to your baby. Insomnia during pregnancy is normal and affects approximately 78% of pregnant women. Insomnia is the perception of inadequate or poor-quality sleep.