"We do not disagree with the result reached by the District Court as to § 3(2). It is true that Doe and Roe clearly establish that the State may not restrict the decision of the patient and her physician regarding abortion during the first stage of pregnancy. Despite the fact that apparently no other Missouri statute, with the exceptions referred to in n 6, supra, requires a patient's prior written consent to a surgical procedure, [Footnote 7] the imposition by § 3(2) of such a requirement for termination of pregnancy even during the first stage, in our view, is not, in itself, an unconstitutional requirement. The decision to abort, indeed, is an important and often a stressful one, and it is desirable and imperative that it be made with full knowledge of its nature and consequences. The woman is the one primarily concerned, and her awareness of the decision and its significance may be assured, constitutionally, by the State to the extent of requiring her prior written consent."