Exercise and Low Blood Pressure During Pregnancy: A Guide

Question
Hi Helene,
I am 5 months pregnant and have recently recovered from pretty severe bouts of morning sickness which had kept me from exercising during the first 4 months.  Unfortunately, now that I am over the morning sickness, I have started having trouble with low blood pressure, as low as 80/50.  I become dizzy, nauseated and on occasion throw up when it gets really low.  My heart rate often increases to the 120s when my blood pressure drops as well.  Today I was put on a modified diet to try to help raise my blood pressure, but I don't know what to do about exercising in the mean time.  My body craves exercise and I haven't been able to exercise for 4 months now due to excessive morning sickness and fatigue, and now that I'm finally getting over those, I really want to get moving again, but I don't know how to do so safely with hypotension throwing a wrench in the mix.  I feel so frustrated!  Do you have any suggestions?  Thank you.

Answer
Moderate level aerobic exercise increases blood pressure while you are doing it, so you don't need to worry about exercise causing your BP to fall further. But you will need to lengthen your post exercise cool down periods to prevent pooling of blood in the legs.

Pregnancy hormones increase vasodilation (this lowers blood pressure to help increase circulation) but this can lead to blood pooling in the legs if you stop exercising too abruptly. Venous return is passive. It's the large muscles of the legs and hips that push blood back up to the heart. So directly after aerobic exercise, when your heart rate is still slightly elevated, if you stop moving, you're likely to have blood pool in your legs, especially if you are already hypotensive.  You should avoid long periods of standing for the same reason too.

When (if) you start to feel a little dizzy, get moving.  Some pregnant women with this type of positional low blood pressure will also experience dizziness from prolonged periods of sitting too. To avoid this, elevate the feet when seated for long periods of time.

Swimming would also be a good choice for you (if you like it and have access to a pool) as the pressure of the water on the body helps to prevent fluid retention.

Start at an easy re-entry level, and slowly build up intensity to where you feel your workouts are "somewhat difficult."

Since your BP is already low, avoid prenatal yoga classes that include restorative poses and meditation as these may lower BP further. Flow style prenatal yoga is more appropriate for you.