In animal studies, embryo-fetal deaths and an increase in diaphragmatic hernias were observed in rats administered this drug daily during the period of organogenesis at oral doses approximately 6 times the maximum recommended human dose (MRHD). In addition, structural abnormalities (e.g., septal defects, ribs fused, sternebrae fused and sternebrae misshapen) were observed in rabbits given daily oral doses during the period of organogenesis at approximately 2 times the MRHD. In animal studies, administration of prostaglandin synthesis inhibitors has been shown to increase pre- and postimplantation loss. In published animal studies, prostaglandin synthesis inhibitors have been reported to impair kidney development when administered at clinically relevant doses. There are no controlled data in human pregnancy. Published reports of NSAID use at about 30 weeks gestation and later in pregnancy have shown NSAIDs may cause premature closure of the fetal ductus arteriosus. Through 2017, the US FDA has received 35 reports of low amniotic fluid levels or kidney problems in mothers who took NSAIDs while pregnant. Five newborns died; 2 had kidney failure and confirmed low amniotic fluid, 3 had kidney failure without confirmed low amniotic fluid. The low amniotic fluid started as early as 20 weeks of pregnancy. There were 11 reports of low amniotic fluid levels during pregnancy and the fluid volume returned to normal after the NSAID was stopped. The medical literature has reported low amniotic fluid levels with use of NSAIDs for varying amounts of time, ranging from 48 hours to multiple weeks. Complications of prolonged oligohydramnios may include limb contractures and delayed lung maturation. In some postmarketing cases of impaired neonatal renal function, invasive procedures such as exchange transfusion or dialysis were required. In other cases, the condition was reversible within 3 to 6 days of stopping the NSAID and in these cases reappeared when the same NSAID was restarted.

NSAIDs may delay or prevent rupture of ovarian follicles which has been associated with reversible infertility in some women. The withdrawal of NSAID therapy should be considered in women with difficulties conceiving or who are undergoing investigation of infertility.

TGA pregnancy category B3: Drugs which have been taken by only a limited number of pregnant women and women of childbearing age, without an increase in the frequency of malformation or other direct or indirect harmful effects on the human fetus having been observed. Studies in animals have shown evidence of an increased occurrence of fetal damage, the significance of which is considered uncertain in humans.
US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D, and X are being phased out.

Contraindicated last trimester of pregnancy
Between 20- and 30-weeks' gestation: Limit dose and duration of use

AU TGA pregnancy category: B3
US FDA pregnancy category: Not assigned

Risk Summary: Use of nonsteroidal anti-inflammatory drugs (NSAIDs) in pregnant women can cause premature closure of the fetal ductus arteriosus and fetal renal dysfunction leading to oligohydramnios and, in some cases, neonatal renal impairment. Embryofetal risks of NSAID use in women in the first or second trimesters of pregnancy are inconclusive. Embryo-fetal deaths and an increase in diaphragmatic hernias were observed in rats administered this drug during the period of organogenesis.

Comments:
-NSAID use in pregnancy prior to 20 weeks gestation should be based on a benefit-risk assessment; some authorities recommend avoiding NSAIDs throughout pregnancy whenever possible.
-If NSAID use is necessary between 20- and 30-weeks' gestation, limit use to the lowest effective dose for the shortest duration possible; ultrasound monitoring of amniotic fluid should be considered if NSAID use extends beyond 48 hours; if oligohydramnios occurs, discontinue NSAID and treat appropriately.
-NSAID use is not recommended in women attempting to conceive as it may impair female fertility.

See references

Benefit should outweigh risk

Excreted into human milk: Yes

Comments:
-Low levels of this drug are excreted in breastmilk and are not expected to cause adverse effects in breastfed infants.
-Some authorities advise women to discontinue nursing or to discontinue the drug, considering the expected benefit of the drug to the mother because of the potential for adverse reaction in nursing infants.

Limited data has shown this drug is excreted into human milk in low levels. Data from 3 published reports estimate the average daily infant dose to be 10 to 40 mcg/kg/day, which is less than 1% of the weight-based therapeutic dose for a 2-year-old. In 2 breastfed infants (17 and 22 months of age) whose mothers took this drug 200 mg orally twice daily for many weeks, blood samples taken 4 hours after a maternal dose were undetectable (less than 10 mcg/L). No infant side effects were observed in these infants.

See references