Therapy with methotrexate during pregnancy can be teratogenic. Some exposures are accidental while some follow treatment of an ectopic pregnancy. A woman of childbearing age receiving methotrexate should use contraception if treated with methotrexate.
Mechanism: folic acid antagonist
Risk factors for embryopathy:
(1) therapy during the first trimester
(2) high dose therapy
Anomalies may include:
(1) growth retardation
(2) skull malformations (microcephaly, forehead retrusion, synostosis)
(3) cardiac malformations (tetralogy of Fallot, other)
(4) failure of bone ossification
(5) scoliosis
(6) facial dysmorphism
(7) single umbilical artery
(8) pulmonary malformations
(9) gastrointestinal malformations
(10) genitourinary malformations (hypospadias, other)
(11) skeletal and limb anomalies (brachydactyly, hypoplastic thumb, clinodactyly, syndactyly, other)
(12) ophthalmic malformations (micropthalmia, other)
