Maternal Lithium Therapy and Polyhydramnios
| Title: | Maternal Lithium Therapy and Polyhydramnios |
|---|---|
| Authors: | Ang, Matthew S.; Thorp, M.D., James A.; Parisi, Valerie M. |
| Publisher: | Obstetrics & Gynecology |
| Date Published: | September 01, 1990 |
| Reference Number: | 338 |
Lithium is widely used in the treatment of bipolar affective disorders, and teratogenic effects include cardiovascular abnormalities, notably Ebstein anomaly. The most common side effect in the patient taking lithium is polyuria, a form of nephrogenic diabetes insipidus. We report the case of a manic-depressive gravida on lithium therapy who developed polyhydramnios in her last trimester. Because lithium crosses the placenta, we postulate that, by a similar mechanism, lithium may cause fetal polyuria which results in polyhydramnios.
This translation by the NDI Foundation is to assist the lay reader. To provide a clear, accessible interpretation of the original article, we eliminated or simplified some technical detail and complicated scientific language. We concentrated our translation on those aspects of the article dealing directly with NDI. The NDI Foundation thanks the researchers for their work toward understanding and more effectively treating this disorder.
© Copyright NDI Foundation 2007 (JC)
The authors' patient developed polyhydramnios, an excess of amniotic fluid, in her last trimester. Since lithium crosses the placenta, and since at twenty weeks the fetus becomes the primary source of amniotic fluid production, the authors postulated that this woman's fetus may have acquired NDI from ingesting lithium circulating through his mother's body. The resulting fetal polyuria would be the cause of the excess of amniotic fluid.
The plasma half-life of lithium in an adult varies from 17 - 36 hours. It is longer in newborns. Due to the drastic decrease in the rate lithium clears from the blood during delivery, the authors' patient had elevated serum lithium ion levels during delivery. Because of the prolonged half-life of lithium in the newborn, the effect of lithium in the newborn's kidney will last several days. The current recommendation is that pregnant women decrease or discontinue lithium 7 - 10 days before delivery.