Prevalence of postpartum depressive symptoms during the first 6 months postpartum: Association with maternal age and parity.
Depressive symptoms are common in postpartum women. The present study aimed to describe changes in the prevalence of depressive symptoms during the first 6 months postpartum, and their association with maternal age and parity.



A prospective cohort study was conducted with 3769 women at 13 hospitals in Japan. Depressive symptoms were measured during hospital stay and at 1, 2, 4, and 6 months postpartum, using the Japanese version of the Edinburgh Postnatal Depression Scale (EPDS). The effects of maternal age and parity were assessed by comparing four groups: younger primiparas (aged <35 years); older primiparas (≥35 years); younger multiparas (<35 years); and older multiparas (≥35 years). Data were analyzed using a mixed between/within-subjects analysis of variance, Cochran's Q tests, and chi-square tests.



Mean EPDS scores significantly decreased from 1 to 2 months postpartum in all groups. The proportion of women with EPDS scores ≥9 significantly decreased during the same period for primiparas but not for multiparas. Primiparas also had significantly higher EPDS scores than multiparas during hospital stay and at 1 month postpartum.



As we used convenience sampling, our study sample was not fully representative of Japanese mothers. This study was also limited by our focus on the postpartum period.



The first month postpartum represented peak prevalence for depressive symptoms. Primiparity was a risk factor for depressive symptoms only during the first month postpartum. Healthcare professionals should be sensitive to postpartum duration and parity when monitoring depressive symptoms.
Graduate School of Nursing, Chiba University, Chiba, Japan. Electronic address: iwthiroko@faculty.chiba-u.jp.
Hiroko
H
Iwata
Graduate School of Nursing, Chiba University, Chiba, Japan.
Emi
E
Mori
Graduate School of Nursing, Chiba University, Chiba, Japan.
Akiko
A
Sakajo
Graduate School of Nursing, Chiba University, Chiba, Japan.
Kyoko
K
Aoki
Graduate School of Nursing, Chiba University, Chiba, Japan.
Kunie
K
Maehara
Graduate School of Medicine, Nagoya University, Aichi, Japan.
Koji
K
Tamakoshi
D000328:Adult; D019052:Depression, Postpartum / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006801:Humans; D007564:Japan; D008423:Maternal Age; D009035:Mothers / Q000523:psychology* / Q000706:statistics & numerical data; D010298:Parity; D049590:Postpartum Period / Q000523:psychology*; D011247:Pregnancy; D015995:Prevalence; D011446:Prospective Studies; D013997:Time Factors