title: Childbirth-related fatigue trajectories during labour.
abstract: OBJECTIVE
  This paper is a report on a study identifying trajectories of childbirth-related fatigue intensity changes over time and the influencing factors related to specific trajectory patterns.
  
  
  BACKGROUND
  Childbirth is a period of time that encompasses considerable physiological and psychological fatigue, often having an adverse impact on women in labour. Empirical studies on this issue are scarce. How childbirth-related fatigue changes over time, and factors influencing fatigue development, remain unclear.
  
  
  METHODS
  A prospective, correlational design with repeated measures was used. Data were collected by self-reported measures and laboratory analysis of blood specimens. From December 2004 to November 2005 a convenience sample of 209 low-risk pregnant Taiwanese women was followed throughout the labour process. Repeated measures of fatigue were analysed by using a semiparametric mixture model. Variables explaining trajectory class membership were identified by means of logistic regression.
  
  
  RESULTS
  Two distinct trajectories of childbirth-related fatigue were identified: low intensity (30.8% of women) and high intensity (69.2% of women). Fatigue level of both classes intensified following labour. The fastest period of fatigue-increasing rate was in the active phase. After birth, fatigue levels in the high-fatigue intensity class remained high. Primiparas in the high-fatigue intensity class experienced significantly more anxiety and higher lactate concentration at admission than the low-intensity class.
  
  
  CONCLUSIONS
  Caregivers should endeavour to prevent high levels of fatigue once women enter the labour phase. Women who present with high fatigue at onset of labour should be targeted for early intervention, especially in the period of rapid fatigue increase.
authors.affiliation: School of Nursing, China Medical University, Taichung, Taiwan. yalingt22@yahoo.com.tw <yalingt22@yahoo.com.tw>
authors.forename: Ya-Ling
authors.initials: YL
authors.lastname: Tzeng
authors.forename: Yu-Mei Y
authors.initials: YM
authors.lastname: Chao
authors.forename: Shu-Yu
authors.initials: SY
authors.lastname: Kuo
authors.forename: Yu Kuei
authors.initials: YK
authors.lastname: Teng
mesh_terms: D000328:Adult; D001007:Anxiety / Q000523:psychology*; D005221:Fatigue / Q000378:metabolism / Q000523:psychology*; D005260:Female; D006801:Humans; D007743:Labor, Obstetric / Q000502:physiology / Q000523:psychology*; D010147:Pain Measurement / Q000523:psychology*; D036801:Parturition / Q000502:physiology / Q000523:psychology*; D011247:Pregnancy; D013624:Taiwan