In plain words
Aortocaval compression happens when the growing uterus presses on the large blood vessels behind it. These are the aorta and the vena cava. Lying flat on your back can make this pressure worse. Blood flow to the heart and the baby can drop for a moment. You may feel dizzy, faint, short of breath, or sick to your stomach. Rolling to one side usually relieves it. Clinicians often advise side-lying positions in late pregnancy and during labor. If you faint, or your baby seems to move less when you lie down, call your provider right away. For a faint that does not recover, call 911.
The deeper version
Aortocaval compression is a in which the gravid uterus compresses the inferior vena cava and aorta, reducing venous return and cardiac output, usually from about 20 weeks onward. Hemodynamic effects are typically compensated by a sympathetic response, and symptomatic occurs in a subset of patients. Supine sleeping in late pregnancy has been associated with risk, with a population attributable risk near 6 percent reported in an individual participant data meta-analysis (Cronin and colleagues, 2019). The mechanism is presumed to be aortocaval compression, though it has not been directly established. Management is positional and clinical. The controversy concerns whether the association is causal, and how to counsel women who sleep on their backs without causing alarm.
Where it comes up
- Can't sleep: pregnancy insomniaPregnancy: Your Body
- Pushing and positions for birthGetting Ready for Birth
- Working while pregnantPregnancy: Mind and Life
What mothers here say about aortocaval compression
No one has posted under this term yet.
Sources
- Gordon A and colleagues — Supine sleep position and stillbirth risk in late pregnancy (2017)