Pregnancy outcome after in utero exposure to baclofen: an ENTIS collaborative study (Baclofen and pregnancy)

Study type

• Study type:
  Non-interventional study
• Scope of the study:
  Assessment of risk minimisation measure implementation or effectiveness

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Study drug International non-proprietary name (INN) or common name:
  BACLOFEN

Population studied

• Age groups:
  Adults (18 to < 46 years)
• Special population of interest:
  Pregnant women
• Estimated number of subjects:
  434

Study design details

• Main study objective:
  To assess the rate of major malformations associated with baclofen exposure during the first trimester of pregnancy
• Outcomes:
  Rate of major malformations, Intrauterine growth retardation (IUGR) prematurity rate (< 37 gestational weeks)Rate of elective terminations of pregnancy (ETOPs). Description of postnatal symptoms after baclofen exposure throughout pregnancy
• Data analysis plan:
  Each baclofen exposued pregnant patient is matched to 3 controls with non-teratogenic exposure, according to age, gestational age at inclusion, year of counseling, and TIS or country.Statistical analysis.- Continuous endpoints comparison: Student's t test. - Categorical endpoints comparison: χ² test or Fisher's exact test when assumptions for χ² are not met. - If a difference is pointed out: logistic regression analysis taking into account all identified possible confounding factors.- Statistical significance set at P value of less than 0.05 (two-sided). With 100 exposed cases the study has a 80% power of detecting a 3.5-fold increase in malformation rate, assuming a 3% baseline risk.