The objective of this narrative review is to study the impact of pregnancy and childbirth on pelvic floor function as assessed by objective measurement techniques with quantitative data carried out during pregnancy and after childbirth. A literature search in MEDLINE and relevant and up-to-date journals from 1960 until April 2017 was performed for articles dealing with the impact of pregnancy and childbirth on pelvic floor function as assessed by objective measurement methods. Only studies describing objective measurement techniques. i.e., urodynamics, ultrasound (US), magnetic resonance imaging (MRI), Pelvic Organ Prolapse Quantification (POP-Q) system, and neurophysiologic tests carried out throughout pregnancy and after childbirth are included. Relevant studies presenting objective quantitative data are analyzed and briefly summarized. The number of studies meeting selection criteria was relatively few. Pregnancy, especially first pregnancy, is associated bladder neck lowering, increased bladder neck mobility, pelvic organ descent, decreased levator ani strength, and decreased urethral resistance. These changes are accentuated after vaginal delivery. Data on the impact of obstetrical and neonatal variables are transient and seem of less importance. Cesarean delivery is not completely protective. In most women, pelvic floor muscle function recovers in the year after delivery. Objective measurement techniques during pregnancy may allow identification of women susceptible to pelvic floor dysfunction later in life and offer the opportunity for counseling and preventive treatment strategies.
Keywords: Cesarean delivery; Childbirth; Objective measurement techniques; Pelvic floor function; Pregnancy; Vaginal delivery.