Investigation of exacerbating factors for postpartum hair loss: a questionnaire-based cross-sectional study.

BACKGROUND: Although postpartum hair loss is believed to be common, there is little reliable information.

OBJECTIVE: We sought to examine the factors that were associated with postpartum hair loss and to elucidate factors correlated with its pathogenesis.

METHODS: We carried out a questionnaire-based cross-sectional study. The study participants were women who delivered at 2 facilities and filled the questionnaire 10-18 months after delivery. The survey questionnaire included baseline characteristics, pregnancy details, delivery, childcare, and extent of postpartum hair loss. We divided participants into 2 groups according to the absence or presence of postpartum hair loss and performed logistic regression analyses.

RESULTS: A total of 331 (21.0%) responses were analyzed; among these 304 (91.8%) women had postpartum hair loss. The average time for the start, peak, and end of hair loss was 2.9, 5.1, and 8.1 months, respectively. Women with hair loss had an earlier time of delivery, a lower birth weight, a higher preterm labor rate, and longer-term breastfeeding. Logistical regression analyses revealed that longer-term breastfeeding and preterm labor were independent predictors of postpartum hair loss. The adjusted odds ratio for postpartum hair loss in women who ended breastfeeding 6-12 months postpartum versus those who ended it after 12 months or more was 5.96 (95% confidence interval [CI] [1.68, 21.09]) and 6.37 (95% CI [1.95, 20.76]) compared with those who stopped breastfeeding within 6 months postpartum.

LIMITATIONS: Finer details such as pregnancy complications and delivery information may not be accurate since all results are based on questionnaire responses. There may be a sampling bias because women who suffer from postpartum hair loss may tend to participate more frequently.

CONCLUSION: Over 90% of women experienced postpartum hair loss. Our data show that long-term breastfeeding and preterm labor correlate with postpartum hair loss.