My fetus has just been diagnosed with macrocephaly and hydrocephalus?

Large Head. The head is larger than normal probably due to the hydrocephalus found on the ultrasound. A consultation with a pediatric neurosurgeon would be great to help you be ready to deal with this when the baby is born.
Fetal MRI! Fetal MRI should be performed to assess the etiology of all fetal hydrocephaly cases; depending on this you may discuss prognosis and treatment options with a pediatric neuro-logist/-surgeon, geneticist, neonatologist and maternal-fetal medicine specialist. At a minimum, i would anticipate and increased risk for cesarean section and need for neonatal head ultrasound and genetic/infectious testing.