As with most drugs, Betaloc ZOK should not be given during pregnancy and lactation unless its use is considered essential.
In general, β-blockers reduce placental perfusion, which has been associated with growth retardation, intrauterine death, abortion and early labour. It is therefore suggested that appropriate maternofetal monitoring be performed in pregnant women treated with metoprolol.
As with all antihypertensive agents, β-blockers may cause side-effects, e.g. bradycardia, in the foetus and in the newborn and breast-fed infant.
The amount of metoprolol ingested via breast-milk, however, seems to be negligible as regards β-blocking effect in the infant if the mother is treated with metoprolol in doses within the normal therapeutic range.