Does Lamotrigine Cause Infertility in Women?
No, lamotrigine does not cause infertility in women. The available evidence from multiple clinical guidelines and research studies consistently demonstrates that lamotrigine has no adverse effects on female fertility.
Evidence from Clinical Guidelines
The most authoritative guideline evidence directly addresses this question:
The CDC Medical Eligibility Criteria for Contraceptive Use (2010) explicitly states that "no drug interactions have been reported among epileptic women taking lamotrigine and using the LNG-IUD" 1, indicating lamotrigine does not interfere with reproductive function or hormonal contraception.
Unlike enzyme-inducing anticonvulsants (phenytoin, carbamazepine, barbiturates), lamotrigine does not affect sex hormone metabolism or binding proteins 1. This is a critical distinction, as enzyme-inducing anticonvulsants can reduce biologically active sex hormone levels and potentially affect fertility 1.
The American Academy of Pediatrics guidelines confirm that lamotrigine is listed among anticonvulsants that do not decrease contraceptive efficacy, further supporting its lack of reproductive toxicity 1.
Fertility Outcomes in Women with Epilepsy
While women with epilepsy may experience reproductive dysfunction, this is primarily related to:
- The epilepsy itself (particularly temporal lobe epilepsy affecting hypothalamic-pituitary function) 1
- Other anticonvulsants, especially valproate, which is associated with polycystic ovary syndrome (PCOS), hyperandrogenism, and menstrual irregularities 1
- Seizure activity causing hormonal disruptions 1
Lamotrigine is not implicated in these reproductive endocrine disorders 1.
Research Evidence on Fertility
A prospective study found no difference in fertility rates between women with epilepsy attempting pregnancy and healthy controls, suggesting that well-controlled epilepsy with appropriate medications does not impair fertility 2.
Pregnancy registries have consistently shown lamotrigine to be among the safest antiepileptic medications, with reassuring data on both maternal and fetal outcomes 3, 4, 5.
Important Caveat: Animal Study Limitations
One animal study 6 reported fertility effects in male rats given lamotrigine, but this finding:
- Has not been replicated in human studies
- Involved male animals (not directly applicable to female fertility)
- Used dosing that may not reflect human therapeutic levels
- Contradicts all human clinical evidence and guidelines
This animal data should not influence clinical decision-making for women, as human evidence consistently demonstrates safety 1, 3, 2.
Clinical Implications
Women taking lamotrigine who wish to conceive can be reassured that the medication does not impair fertility 1, 7. In fact:
- Lamotrigine is considered a preferred anticonvulsant for women of childbearing age due to its favorable safety profile 3, 2
- Maintaining seizure control with lamotrigine during pregnancy planning is important, as uncontrolled seizures pose greater risks than the medication itself 7, 2
- Folic acid supplementation (>400 mcg/day) should be started early in women planning pregnancy 2