Because all fetal systems are growing and developing throughout the pregnancy, the fetal brain is also developing gradually. So there is a probability that hydrocephalus will not be detected in the fetus until 38 weeks of late pregnancy. Widening of the lateral ventricles or hydrocephalus in the fetus is often seen during a woman’s late pregnancy checkup, which is determined by ultrasound and magnetic resonance imaging (MRI). The brain of the fetus develops gradually throughout the pregnancy, so even if the tests in early and mid-pregnancy are normal, hydrocephalus may occur in late pregnancy. Hydrocephalus in the fetus can form for a number of reasons, the first of which is the production of too much cerebrospinal fluid. For example, something like diffuse choroidal hyperplasia of the choroid plexus can potentially lead to the production of too much cerebrospinal fluid. However, when fetal hydrocephalus is detected, it is recommended that a further MRI is needed, followed by a consultation at a prenatal diagnostic center to give a treatment plan.