Lithium and Pregnancy (511/1700)

A 26yo woman had bipolar disorder for 10yrs and is on Lithium for it. She is symptom free for
the past 4 years. She is now planning her pregnancy and wants to know whether she should
continue taking lithium. What is the single most appropriate advice?
a. Continue lithium at the same dose and stop when pregnancy is confirmed
b. Continue lithium during pregnancy and stop when breast feeding
c. Reduce lithium dosage but continue throughout pregnancy
d. Reduce lithium gradually and stop when pregnancy is confirmed
e. Switch to sodium valproate




































answer: D

Lithium in pregnancy (1):

• lithium is teratogen - increases the incidence of Ebstein's anomaly by a factor of 10 to 1:2000 births.
• increased associated miscarriage risk with lithium treatment during pregnancy.
• reported rate of major congenital malformations is around 4-12% in babies exposed in utero to lithium

Other drugs used in the management of bipolar affective disorder and there incidence of major congenital malformatons if used in pregnancy are (2):

• 5-6% in valproate-exposed babies have major congenital malformations
• 2.3-5.3% in carbamazepine-exposed babies have major congenital malformations
  • compares with a rate of 2.4-4.5% in the general population

The period of highest risk for organ malformation is the first 8 weeks of pregnancy
Any female of child-bearing potential should receive appropriate advice about contraception

• she should be encouraged to plan her pregnancies and should be advised carefully about the benefits and risks of the various treatment options open to her should she decide to try to become pregnant
  • options may include gradual discontinuation of some or all medication before conception, or switching to agents with lower risk to the fetus, or continuing with existing treatment
  • she will also need advice about antenatal diagnosis of fetal abnormality if she decides to remain on drug treatment
  • physiological changes during the pregnancy may necessitate dose adjustment to ensure that therapeutic serum concentrations are maintained

All drugs used in the treatment of bipolar disorder are secreted in breast milk in varying degrees, but the risks to the newborn baby are uncertain (2)
NICE have stated that (3):

• lithium should not be routinely prescribed for women, particularly in the first trimester of pregnancy (because of the risk of cardiac malformations in the fetus) or during breastfeeding (because of the high levels in breast milk)
• if a woman taking lithium is planning a pregnancy, and is well and not at high risk of relapse, she should be advised to stop taking the drug because of the risk of cardiac malformations in the fetus
• if a woman who is taking lithium becomes pregnant:
  • if the pregnancy is confirmed in the first trimester, and the woman is well and not at high risk of relapse, lithium should be stopped gradually over 4 weeks; it should be explained that this may not remove the risk of cardiac defects in the fetus
  • if the woman is not well or is at high risk of relapse, the following should be considered:
    • switching gradually to an antipsychotic, or
    • stopping lithium and restarting it in the second trimester if the woman is not planning to breastfeed and her symptoms have responded better to lithium than to other drugs in the past, or - continuing with lithium if she is at high risk of relapse
• if a woman continues taking lithium during pregnancy, serum lithium levels should be checked every 4 weeks, then weekly from the 36th week, and less than 24 hours after childbirth; the dose should be adjusted to keep serum levels towards the lower end of the therapeutic range, and the woman should maintain adequate fluid intake
• women taking lithium should deliver in hospital, and be monitored during labour by the obstetric team. Monitoring should include fluid balance, because of the risk of dehydration and lithium toxicity (in prolonged labour, it may be appropriate to check serum lithium levels