8.1Pregnancy Risk Summary
GBCAs cross the placenta and result in fetal exposure. In human placental imaging studies, contrast was visualized in the placenta and fetal tissues after maternal GBCA administration. Based on animal studies, use of GBCAs during pregnancy may result in fetal gadolinium retention. Published epidemiological studies on the association between GBCAs and adverse fetal outcomes have reported inconsistent findings and have important methodological limitations (see Data ).
In animal reproduction studies, no teratogenicity was observed with repeated daily intravenous administration of gadoxetate disodium to rats during organogenesis at doses up to 32 times the recommended single human dose; however, an increase in preimplantation loss was noted at doses 3.2 times the single human dose. Post implantation loss was observed with repeated daily intravenous administration of gadoxetate disodium to rabbits on gestation days 6 through 18 at doses 26 times the recommended single human dose (see Data ) .
Because of the potential risks of gadolinium to the fetus, use EOVIST only if imaging is essential during pregnancy and cannot be delayed. The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.
Data Human Data Available data regarding exposure to GBCAs during pregnancy from published epidemiological studies are not sufficient to assess the risk of adverse fetal and neonatal effects that may be associated with GBCAs. A retrospective cohort study of over 1.4 million pregnancies in Ontario, Canada, comparing pregnant women who had a GBCA MRI to pregnant women who did not have an MRI, reported a higher occurrence of stillbirths and neonatal deaths in the group receiving GBCA MRI.
Limitations of this study include a lack of comparison with non-contrast MRI and lack of information about the maternal indication for MRI. Another retrospective cohort study of over 11 million pregnancies in the Medicaid database found no increased risk of fetal or neonatal death or Neonatal Intensive Care Unit admission when comparing pregnancies exposed to GBCA MRI versus non-contrast MRI. These two retrospective studies assessed a limited number of potential pregnancy outcomes and did not evaluate the full spectrum of potential fetal risk.
Animal Data Gadolinium Retention GBCAs administered to pregnant non-human primates (0.1 mmol/kg on gestational days 85 and 135) result in measurable gadolinium concentration in the offspring in bone, brain, skin, liver, kidney, and spleen for at least 7 months. GBCAs administered to pregnant mice (2 mmol/kg daily on gestational days 16 through 19) result in measurable gadolinium concentrations in the pups in bone, brain, kidney, liver, blood, muscle, and spleen at one month postnatal age.
Reproductive Toxicology Animal reproductive and developmental toxicity studies were done in rats and rabbits. Gadoxetate disodium was not teratogenic when given intravenously during organogenesis to pregnant rats at doses up to 32 times the recommended single human dose (mmol/m 2 basis). However, an increase in preimplantation loss was noted at 3.2 times the human dose (mmol/m 2 basis). Compared to untreated controls, rates of post implantation loss and absorption increased and litter size decreased when pregnant rabbits received gadoxetate disodium at doses 26 times the recommended human single dose (mmol/m 2 basis).
This occurred without evidence of maternal toxicity. Because pregnant animals received repeated daily doses of gadoxetate disodium, their overall exposure was significantly higher than that achieved with the standard single dose administered to humans.
