Natural childbirth. A review and analysis.

A review and critique of the literature relating to the effectiveness of psychoprophylaxis (natural childbirth) is made. Based on this review, it is concluded that a variety of methodologic errors have confounded the measurement of treatment effects. An outline of these issues is presented, and it is pointed out that an elucidation of the relationship between treatment and outcome cannot occur until researchers become aware of certain factors that are essential to the validity of their experiments. These factors include the following: 1) the use of a random assignment of subjects to treatment and control groups; 2) the inclusion of a group of controls that receive an attention-placebo treatment; 3) the utilization of obstetricians who are unaware of the type of preparation their patients have received; 4) a careful specification of the details of each treatment procedure; and 5) the utilization of psychologic tests that are appropriate for the purpose of measuring pain and anxiety reduction.