Untreated TB in pregnancy is associated with an increased risk of miscarriage and major fetal abnormality, and treatment of pregnant women. The US guidelines recommend omitting PZA when treating TB in pregnancy; the UK and WHO guidelines make no such recommendation, and PZA is commonly used in pregnancy. There is extensive experience with the treatment of pregnant women with TB and no toxic effect of PZA in pregnancy has ever been found. High doses of RMP (much higher than used in humans) causes neural tube defects in animals, but no such effect has ever been found in humans. There may be an increased risk of hepatitis in pregnancy and during the puerperium. It is prudent to advise all women of child-bearing age to avoid getting pregnant until TB treatment is completed.