The MHRA 2022 safety warning: What the evidence shows
In April 2022, the UK Medicines and Healthcare products Regulatory Agency (MHRA) issued a formal Drug Safety Update based on a large observational registry study of more than 2,700 pregnant women across the Nordic countries (Denmark, Finland, Sweden, and Norway) who were prescribed Pregabalin during early pregnancy.
| Pregnancy Group | Rate of Major Birth Defects | Absolute Risk Context |
|---|---|---|
| General Population (Unexposed) | 4.1% (approx 4 in 100) | Baseline background risk of congenital anomalies in the general population. |
| First-Trimester Pregabalin Exposure | 5.9% (approx 6 in 100) | A small but statistically significant increase in risk (roughly 2 extra cases per 100 live births). |
The congenital malformations observed included structural defects affecting the nervous system, eyes, face (cleft palate), heart, and urinary system. The MHRA concluded that Pregabalin should not be used during pregnancy unless the benefit to the mother clearly outweighs the potential risks to the unborn child.
Why you must never stop Pregabalin abruptly
Sudden cessation can cause severe harm to both mother and baby:
- Breakthrough seizures: If you take Pregabalin for epilepsy, sudden withdrawal can provoke prolonged status epilepticus seizures, which deprive the fetus of oxygen and carry high maternal and fetal mortality risks.
- Severe autonomic withdrawal: Profuse vomiting, dehydration, extreme maternal tachycardia, and hyperthermia can destabilize the pregnancy.
- Acute mental health crisis: If taken for generalised anxiety, sudden stopping can cause severe panic, suicidal ideation, and acute psychiatric decompensation.
Instead, call your GP surgery or maternity unit for a same-day appointment. Your doctor will carefully weigh the risks and, if appropriate, plan a controlled, gradual reduction or switch you to a safer alternative.
Pregnancy planning and effective contraception
Under UK prescribing guidance:
- Women of childbearing potential should use effective contraception while taking Pregabalin.
- Pregabalin does not interact with the contraceptive pill, patches, injections, or hormonal implants.
- Pre-conception review: If you are planning to become pregnant, speak to your specialist at least 3 to 6 months before trying to conceive. This allows time to evaluate whether Pregabalin is still needed, slowly taper off the drug, or optimize non-pharmacological therapies before conception occurs.
Does Pregabalin affect male fertility or fathering a child?
Men frequently ask whether taking Pregabalin can harm a baby they father:
- Pre-clinical animal studies showed reversible reductions in sperm motility and mild testicular changes at high doses.
- However, large human observational studies have found no evidence of an increased risk of congenital birth defects in children fathered by men taking Pregabalin.
- If you are a man taking Pregabalin and have concerns about fertility, speak with your GP.
Breastfeeding safety and infant monitoring
Pregabalin passes into human breast milk, but only in relatively small quantities (the relative infant dose is estimated at approximately 0.2% to 0.3% of the maternal weight-adjusted dose).
The decision to breastfeed involves balancing the substantial nutritional, immunological, and bonding benefits of breast milk against potential medication exposure:
- Healthy, full-term babies: Many women breastfeed successfully while taking moderate doses of Pregabalin under paediatric supervision.
- Premature or low-birth-weight infants: Extra caution is required because an infant’s immature kidneys clear Pregabalin much more slowly.
- What to monitor in the infant:
- Excessive sleepiness, difficulty waking the baby for feeds
- Weak sucking reflex or poor weight gain
- Unusual floppiness (hypotonia) or breathing pauses
If you observe any of these symptoms in your baby, seek urgent paediatric advice.
Specialized UK pregnancy resources
- Bumps (Best Use of Medicines in Pregnancy): Free, evidence-based leaflets for expectant mothers maintained by the UK Teratology Information Service (medicinesinpregnancy.org).
- UK Teratology Information Service (UKTIS): National clinical toxicology service advising NHS healthcare professionals on fetal medication safety (uktis.org).
- NHS Perinatal Mental Health Teams: Specialized regional services supporting pregnant and postpartum women taking psychiatric medicines.