- Design
- Systematic review and random-effects meta-analysis of observational studies
- Population
- 554 women with bipolar I or II disorder across 8 studies
- Primary outcome
- Postpartum recurrence of mood episodes
- Effect
- Pooled recurrence 0.21 (95% CI 0.15–0.29) with lithium vs 0.41 (0.33–0.50) without
A systematic review and meta-analysis pooled eight studies of 554 women with bipolar I or II disorder that reported postpartum recurrence by lithium exposure, plus two studies of lithium discontinuation. Searches ran to April 2026, with random-effects pooling.
The pooled recurrence proportion was 0.21 (95% CI 0.15–0.29) in women on lithium and 0.41 (0.33–0.50) in those not on it. About half started prophylaxis during pregnancy. The discontinuation studies pointed the same way.
The authors themselves flag the main weakness: women were not randomised, so those who took lithium may have differed in severity, support or engagement. The direction fits existing practice, which already treats the postpartum weeks as the highest-risk window in bipolar disorder. The useful step is planning prophylaxis with psychiatry before delivery, not after the first relapse.
- Identify bipolar disorder at booking and refer early for joint perinatal psychiatry planning.
- Decide before delivery whether lithium prophylaxis will be continued or started, and who will monitor levels.
- Plan for the fluid shifts around delivery, when lithium levels can change quickly.
- Arrange early postpartum mental health review, as the first weeks carry the highest relapse risk.
Why it matters
It puts a rough number on postpartum relapse risk to use when counselling a woman with bipolar disorder about prophylaxis.
Don't overread it
The groups were not randomised — confounding by indication could inflate the apparent benefit.
The statistics, in plain English
The two confidence intervals (15–29% and 33–50%) do not overlap, so the difference is unlikely to be chance. But these are pooled proportions from observational groups, not a randomised comparison, so part of the gap may reflect who chose lithium rather than what lithium did.
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