There are other less common but arguably more serious anomalies which affect what is known as the craniospinal column. This is basically made up of the cranium (skull) and the spine. Abnormalities of the skull will range from the most serious anencephaly (where the skull is missing - a condition which is incompatible with life) through hydrocephaly (increased size of head) to microcephaly (small head).
This is a wide field in the sense that there are several "in between" anomalies, and a variety of underlying causes - which may be genetic, or even as a result of infections or alcohol abuse during pregnancy. There is also the fact that many of these conditions may be associated with other abnormalities elsewhere, such as the heart or the gut. It will therefore be presumptuous to say we have given answers to all pertinent questions on this. We have, however, tried to give clear answers to most of the obvious questions on this subject.
Whether a parent will choose to have a termination as a result of a diagnosis of a particular condition is a complex question. While there has been candid imparting of facts about which conditions are compatible with life (and which are not), there is a realization on our part that this is not the only important question in this situation.
Ultimately, the mother is the one who is going to have to live with the after-effects of her decision, whichever this might be. She is therefore the one best placed to know what she can be at peace with. One simple but profound "discovery" of the last twenty years is the fact that taking folic acid at no more than 5 mg daily before conception and during the early weeks of pregnancy dramatically reduces the chances of the baby being affected by spina bifida. It is a simple, inexpensive and safe preventative measure.
In the course of setting the record straight, the issue of hydrocephaly needs to be mentioned. This is widely but erroneously known as "water on the brain". In this condition the water is around rather than on the brain. The only abnormality is therefore the increase in the quantity of the fluid, a state of affairs that might stifle brain development.