The FDA considered the following data:
Prescription NSAIDs and miscarriage
The FDA reviewed five observational studies that evaluated the risk of the spontaneous loss of a pregnancy before the 20th week with NSAID use. Three were retrospective and subject to the associated limitations of this study design; the other two were prospective but did not produce consistent results. Based on their evaluation of these observational studies, the FDA believes that the weight of evidence is inconclusive regarding a possible connection between NSAID use and miscarriage.
Opioids and neural tube defects
The FDA reviewed two retrospective case-control studies that reported opioid exposure in early pregnancy was more common in mothers of infants with neural tube defects. Bother studies were susceptible to similar study limitations (for example use of maternal interviews and possible recall bias) and the FDA concluded further investigation is needed before they can determine whether the weight of evidence supports the presence of an increased risk of neural tube defects related to opioid exposure in early pregnancy. If there is such an increased risk, this would represent only a small absolute increase as the absolute risk of neural tube defects in the general population is low.
Paracetamol and ADHD
The FDA evaluated one prospective cohort study that reported an increased association between paracetamol use in pregnancy and ADHD in children. The study had a number of methodological limitations that make the findings difficult to interpret, and the FDA believe that the weight of evidence regarding this possible connection is currently inconclusive.
Due to the potential methodological limitations and/or the conflicting results noted in the reviewed evidence, the FDA was unable to draw any reliable conclusions and as a result their recommendations on how pain medicines are used during pregnancy will remain the same at this time. Healthcare professionals are advised to continue to follow the existing recommendations in current drug labels and discuss with each patient the benefits and risks of analgesic use during pregnancy, which may differ among patients and by treatment indication.
Abstracts from the UK Teratology Information Service (UKTIS) on use of paracetamol and NSAIDs during pregnancy are available at the links below. Abstracts on a number of different opioids (e.g. morphine; codeine) are also available.