Risk Summary   
Use of NSAIDs, including flurbiprofen, during the third trimester of pregnancy increases the risk of premature closure of the fetal ductus arteriosus. Avoid use of NSAIDs, including flurbiprofen, in pregnant women starting at 30 weeks of gestation (third trimester). 

There are no adequate and well-controlled studies of flurbiprofen in pregnant women. Data from observational studies regarding potential embryo-fetal risks of NSAID use in women in the first or second trimesters of pregnancy are inconclusive. In the general U.S. population, all clinically recognized pregnancies, regardless of drug exposure, have a background rate of 2 to 4% for major malformations, and 15 to 20% for pregnancy loss. In animal reproduction studies, delayed parturition, prolonged labor, stillborn fetuses, and the presence of retained fetuses at necropsy occurred following treatment of pregnant rats treated with oral flurbiprofen throughout gestation until labor at less than 1-time the human dose of 300 mg/day. Embryofetal lethality was seen in pregnant rats and rabbits administered oral flurbiprofen during the period of organogenesis at exposures 0.03-times and 0.5 times, respectively, the human dose of 300 mg. No evidence of malformations were noted in rats, rabbits, or mice treated with flurbiprofen during the period of organogenesis at doses that were 0.8-, 0.5-, and 0.2-times the maximum human daily dose [see Data]. Based on animal data, prostaglandins have been shown to have an important role in endometrial vascular permeability, blastocyst implantation, and decidualization. In animal studies, administration of prostaglandin synthesis inhibitors such as flurbiprofen, resulted in increased pre- and post-implantation loss. 

Clinical Considerations   
Labor or Delivery   
There are no studies on the effects of flurbiprofen during labor or delivery. In animal studies, NSAIDS, including flurbiprofen, inhibit prostaglandin synthesis, cause delayed parturition, and increase the incidence of stillbirth. 

Data   
Animal data   
Pregnant rats were treated with oral doses of 0.05, 1, and 3 mg/kg flurbiprofen 14 days prior to mating through Gestation Day (GD) 16. Embryofetal lethality was seen at 1 mg/kg and above (0.03 times the maximum recommended human dose [MRHD] of 300 mg on a mg/m 2 basis). No maternal toxicity was evident at this dose. No malformations were seen in fetuses from pregnant rats administered flurbiprofen during the period of organogenesis at doses up to 25 mg/kg (0.8 times the MRHD on a mg/m 2 basis). Maternal toxicity (uterine hemorrhage, gastric ulcers) was observed at this dose. 

Pregnant rabbits were administered oral doses of 0.675, 2.25, and 7.5 mg/kg flurbiprofen from GD 1 through GD 29. Embryofetal lethality, but no evidence of teratogenicity, was seen at 7.5 mg/kg (0.5 times the MRHD of 300 mg on a mg/m 2 basis). Maternal toxicity (gastric ulcers and lethality) was observed at this dose. 

Pregnant mice were treated with oral doses of 2, 5, and 12 mg/kg flurbiprofen from GD 3 to 18. An increased incidence of fetal lethality occurred in the 12 mg/kg group (0.2 times the MRHD). All doses were associated with some evidence of maternal toxicity (placental hemorrhage). 

Pregnant rats were treated with oral doses of 0.2, 0.675, 2.25, 7.5, and 25 mg/kg flurbiprofen from GD 1 until labor. Delayed delivery, the incidence of stillborn pups, and decreased pup viability, were noted at doses of 2.25 mg/kg and higher (0.07 times the MRHD). These doses were associated with maternal toxicity (uterine hemorrhage, gastrointestinal ulceration, decreased body weight). 

Pregnant rats treated with oral doses of 0.4, 4, and 10 mg/kg flurbiprofen from GD 16 to labor, delayed parturition was seen at 0.4 mg/kg and above and stillborn pups were seen at 4 mg/kg and above (0.01-times and 0.13 times, respectively, the MRHD on mg/m 2 basis). Uterine hemorrhage, ulceration, and mortality were noted in dams at 0.4 mg/kg and above.