title: What is the normal pattern of uterine involution? An investigation of postpartum uterine involution measured by the distance between the symphysis pubis and the uterine fundus using a paper tape measure.
abstract: OBJECTIVE
  To describe normal postnatal uterine involution in a small sample of healthy primiparous women, and estimate the proportion who have a decline in the distance between the symphysis pubis and the uterine fundus (S-FD) slow enough to have the potentiality to trigger further clinical action, using currently accepted criteria for intervention.
  
  
  METHODS
  A maternity unit in the south of England that has approximately 6000 deliveries per annum and the related community areas.
  
  
  METHODS
  Daily measurement of the S-FD was carried out in 28 healthy women from within 18 hours of delivery until the uterine fundus was no longer palpable abdominally. Graphs showing the daily measurements and correlation coefficients were used to describe involution. The proportion of healthy women who would have been identified as healthy by the screening method was estimated (its specificity).
  
  
  RESULTS
  Considerable variability was found in the pattern of uterine involution that was experienced by the women who had a normal puerperium. The measurement of the S-FD has a low specificity with only 6 of the 28 women (21.4%; 95% CI 8.3% to 40.9% having had no episodes of the S-FD declining slowly (less than 1 cm over three days). There was a weak, positive correlation between the S-FD measurement on day one and the day on which the uterus ceased to be palpable (r = 0.426, P = 0.03). No relationship was found between method of baby feeding and the day on which the uterus ceased to be palpable.
  
  
  CONCLUSIONS
  The measurement of S-FD using a paper tape measure should not form part of routine postpartum assessment.
authors.affiliation: University of Southampton, Princess Anne Hospital, Hants, UK.
authors.forename: E R
authors.initials: ER
authors.lastname: Cluett
authors.forename: J
authors.initials: J
authors.lastname: Alexander
authors.forename: R M
authors.initials: RM
authors.lastname: Pickering
mesh_terms: D000293:Adolescent; D000328:Adult; D000886:Anthropometry / Q000295:instrumentation / Q000379:methods*; D015400:Clinical Nursing Research; D005260:Female; D006801:Humans; D009730:Nursing Assessment / Q000379:methods*; D049590:Postpartum Period / Q000502:physiology*; D011247:Pregnancy; D011630:Pubic Bone / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014599:Uterus / Q000502:physiology*