Multiple large cohort and registry studies indicate that the use of ibuprofen and other nonsteroidal anti-inflammatory drugs (NSAIDs) during early pregnancy is significantly associated with an increased risk of miscarriage or spontaneous abortion.
Papers [0] and [2] directly investigate the relationship between ibuprofen/NSAID use during pregnancy and spontaneous abortion/miscarriage, concluding that there is a statistically significant positive association. No provided papers refute this relationship.