Cannabis is commonly used among pregnant women. It is unclear whether cannabis exposure
causes hemodynamic modifications in the fetus, like tobacco does.
This study aims to ascertain fetal blood redistribution due to intrauterine cannabis
This study was embedded in the Generation R Focus Study, a population-based cohort
of parents and children followed from pregnancy onwards. In late pregnancy, fetal
hemodynamics was assessed with ultrasound measurements in cannabis-exposed and non-exposed
fetuses. Pregnant women reported about substance use during pregnancy. A distinction
was made between continued cannabis use (n=9), cannabis use only in early pregnancy
(n=14), continued tobacco use (n=85), tobacco use only in early pregnancy (n=92),
and no tobacco or cannabis use during pregnancy (n=85).
Continued cannabis use was associated with an increased pulsatility and resistance
index of the uterine artery, while discontinued cannabis use was associated with a
decreased pulsatility, and resistance index, as compared to controls. Additionally,
continued cannabis exposure resulted in a significantly higher uterine pulsatility
index and uterine resistance index compared to tobacco exposure. Continued cannabis
use was found to be associated with a smaller aortic diameter, as well. No association
between intrauterine cannabis exposure and the fetal cerebral vascular system was
Our findings suggest that intrauterine cannabis exposure was associated with changes
in hemodynamic programming of the vascular system of the fetus in late pregnancy mainly
due to tobacco exposure, but intrauterine cannabis exposure did demonstrate a specific
effect on the uterine blood flow.
2010. Published by Elsevier Ireland Ltd.