AU: Safety has not been established during pregnancy. Tetracyclines are considered safe for use during the first 18 weeks of pregnancy (16 weeks postconception); use should be avoided during the second and third trimesters of pregnancy.
UK: Use is contraindicated; use is not recommended unless considered essential.
US: The manufacturer makes no recommendation regarding use of the immediate-release products during pregnancy; use of the extended-release products is not recommended.

AU TGA pregnancy category: D
US FDA pregnancy category:
-Most formulations: D
-Immediate-release oral capsules: Not assigned.

Risk summary: Use of this drug in pregnant women may cause fetal harm.

Comments:
-If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential harm to the fetus.
-Use of tetracyclines after the first 18 weeks of pregnancy may affect the formation of the baby's teeth and cause discoloration.

Animal studies have revealed evidence of embryofetal toxicity, including toxic effects on skeletal formation. Bent limb bones were observed in fetuses of pregnant rats and rabbits given doses of 30 mg/kg/day and 100 mg/kg/day, respectively; mean fetal body weight was reduced when pregnant rats were given doses of 10 mg/kg/day. There are no controlled data in human pregnancy; however, this drug crosses the placenta and may cause fetal harm.

Congenital anomalies including limb reduction have been reported rarely during postmarketing experience. When used during tooth development (second half of pregnancy) tetracyclines may cause permanent yellow-grey-brown discoloration of the teeth; this side effect is more common during prolonged use but has been seen after short-term therapy. Enamel hypoplasia has also been reported.

Tetracyclines used during the last trimester form a stable calcium complex throughout the human skeleton.

AU TGA pregnancy category D: Drugs which have caused, are suspected to have caused or may be expected to cause, an increased incidence of human fetal malformations or irreversible damage. These drugs may also have adverse pharmacological effects. Accompanying texts should be consulted for further details.

US FDA pregnancy category D: There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

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.

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Tetracyclines have been considered contraindicated during breastfeeding due to possible staining of infants' dental enamel or bone deposition of tetracyclines; however, a close review of available literature suggests harmful effects are unlikely with short-term use of this drug during lactation as milk levels are low and infant absorption is inhibited by the calcium in breast milk.

According to some experts, this drug should be avoided; the nursing infant's teeth may be stained with prolonged maternal therapy.

After a single 200 mg oral dose in 2 patients (time postpartum not provided), a peak milk level of 0.8 mg/L was reached 6 hours after dosing. Milk levels averaged between 0.5 and 0.8 mg/L during the 12 hours after dosing; a total of 18 mcg was excreted during this time.

After using this drug (100 mg twice a day) for almost 4 years, a woman developed galactorrhea after taking perphenazine, amitriptyline, and diphenhydramine; the breast secretion was black. In another woman (who produced occasional small amounts of breast milk during the 18 months after weaning), expressed milk had become black 3 to 4 weeks after starting 150 mg/day orally; iron levels in her milk were more than 100 times higher than iron levels found in normal milk and her mammogram was normal. In both cases, macrophages containing a black, iron-containing pigment were found in the milk; the pigment is thought to be an iron chelate of this drug or 1 of its metabolites.

LactMed: Short-term use is considered acceptable; as a precaution (theoretical), prolonged or repeat courses should be avoided throughout breastfeeding.
-According to some authorities, use is contraindicated; according to other authorities, a decision should be made to discontinue breastfeeding or discontinue the drug, taking into account the importance of the drug to the mother.

Excreted into human milk: Yes

Comments:
-The effects in the nursing infant are unknown; the infant should be monitored for rash and possible effects on the gastrointestinal flora (e.g., diarrhea or candidiasis [thrush, diaper rash]).
-According to some authorities, permanent tooth discoloration may occur in developing infants; enamel hypoplasia has been reported.
-Black discoloration of breast milk has been reported with this drug.
-Tetracycline, a related drug, is considered compatible with breastfeeding by the American Academy of Pediatrics.

See references