When should lithium be stopped and restarted during the third trimester of pregnancy?

Management of Lithium During the Third Trimester of Pregnancy

Lithium should be temporarily discontinued 24-48 hours before anticipated delivery and restarted 6-12 hours postpartum at a reduced dose to minimize neonatal complications while maintaining maternal mood stability. 1

Lithium Management in Late Pregnancy

When to Stop Lithium

• Discontinue lithium 24-48 hours before planned delivery (scheduled cesarean section or induction) or upon admission for spontaneous labor 1
• This brief discontinuation is associated with only slight maternal lithium level fluctuations (around 0.20 mEq/L) while reducing neonatal exposure 1
• Complete lithium discontinuation during pregnancy is not recommended due to high risk of maternal relapse 2

Monitoring During Third Trimester

• Monitor lithium blood levels weekly during the third trimester due to physiological changes affecting lithium clearance 2
• Target therapeutic lithium levels should be maintained until planned discontinuation before delivery 3
• Avoid sodium-restricted diets and diuretics during pregnancy as they can increase lithium levels and risk of toxicity 4

Risks of Continued Lithium Use Through Delivery

• Lithium completely crosses the placenta with a mean umbilical cord/maternal lithium ratio of 1.10 1
• Approximately 56% of neonates exposed to lithium at delivery present with transient acute complications 1
• Neonatal hypotonia is the most frequent complication, with higher lithium levels (0.178 mEq/L higher) associated with increased risk 1
• Other potential neonatal complications include respiratory distress, lethargy, poor feeding, and transient thyroid abnormalities 2, 5

Restarting Lithium Postpartum

• Resume lithium 6-12 hours after delivery 1
• Consider a higher therapeutic target level postpartum due to very high risk of relapse during this period 2
• Early postpartum relapse rate is approximately 6% when following this protocol 1
• Careful monitoring of lithium levels is essential in the immediate postpartum period due to rapid physiological changes 2

Special Considerations

• Delivery should ideally take place in a specialized hospital where psychiatric and obstetric care for the mother and neonatal monitoring can be provided immediately after birth 2
• High-resolution ultrasound with fetal anomaly scanning at 20 weeks is recommended for pregnancies with lithium exposure 2
• Most clinical guidelines discourage breastfeeding for women taking lithium due to potential infant exposure 2

Alternative Approaches

• For women with severe bipolar disorder who cannot safely discontinue lithium even briefly, maintaining treatment through delivery may be necessary 5
• In such cases, the lowest effective dose should be used, with close neonatal monitoring for complications 5
• The risk-benefit assessment must guide clinicians and patients in the decision to continue lithium during delivery 5