Main Findings
This large prospective study aimed to determine and distinguish the main
determinants of early and late PPD. While both forms shared some common
factors, several factors were specific to only one form of PPD. Another
important finding is that PPD is not only associated with psychiatric
risk factors (personal or family history), but also with childhood
trauma and stressful life events occurring during pregnancy and
delivery. More specifically, early PPD was associated independently with
a personal history of depression, emotional neglect during childhood,
stressful life events during pregnancy and concomitant chronic physical
disease. Late PPD was associated with unemployment, personal and family
history of mood disorder, emotional abuse during childhood, stressful
life events during pregnancy, emergency consultation during pregnancy,
and serious post-partum complications.
Stressful life events during pregnancy were associated with both early
and late PPD in our cohort, in accordance with previous studies (2,37).
However, the majority of women experience such stressful life events and
most do not develop PPD. In the present study, we took into account the
woman’s subjective experience for each stressful life event and
considered the real impact of each event. We have also revealed a
cumulative effect of these life events: each additional event increased
the risk of PPD. A cumulative effect of stressful life events in the
year before pregnancy has been shown to have an impact on depression
during pregnancy (38). This “dose-effect” is important in clinical
practice: the risk of PPD increases with each additional stressful
event.
The impact of childhood trauma on PPD was controversial: some studies
reported this association (44,45), while others did not (46,47). Our
study not only confirms that childhood trauma is associated with PPD,
but also shows that emotional neglect specifically has an impact on
early PPD, while emotional abuse is associated with late PPD. Further
research is needed to better understand this point.
As with early adversities, we have shown that recent stressful events
are also associated with PPD. Regarding obstetric factors before
pregnancy, only a concomitant chronic physical disease was associated
with early PPD. Infertility and assisted reproductive technology were
not associated with PPD, confirming recent findings (39,40). During
pregnancy, we highlighted that consulting in the emergency room is an
important factor associated with PPD. An Australian study found
consistent results, with more emergency room visits during pregnancy
among women requiring hospitalization for PPD (41). Whether this is due
to an underlying psychological condition, social stress factors,
pregnancy complications, or to the stress associated with the emergency
consultation itself is not known and needs further exploration. Finally,
perineal trauma had an impact only on early PPD, and this effect
disappeared with distance from childbirth; confirming the results of
Dunn et al. (42). In our study, episiotomy or cesarean section were not
associated with PPD. Data on C-section are conflicting (17,43,44).
Having a personal history of a psychiatric disorder was associated with
a higher risk of both early and late PPD, which is consistent with the
literature (17). One of the most strongly associated factors was a
personal history of depression, in line with published data (1,2,17,48).
Having a history of anxiety disorder was also associated with early and
late PPD although the final model did not retain it, as shown by
previous literature (19,49,50). In addition, a history of attempted
suicide increased the risk of early and late PPD in our study. In a U.S.
population study, a history of attempted suicide was associated with
perinatal depression with an adjusted OR of 3.79 (37).
Women with early and late PPD were both more likely to report a family
history of mood disorder than controls (53% and 60% vs. 47%
respectively). There was a significant difference between women with
late PDD and controls for family history of mood disorder disorders
(p<.001), but not between women with early PPD and controls,
suggesting a smaller effect of family history on early PPD. A recent
study based on Danish population-based registers found that parental
psychiatric history of depression, bipolar disorder or schizophrenia was
associated with postpartum psychiatric disorders, especially among women
with personal psychiatric history (51). For women with a psychiatric
history, the postpartum period appears to be a time frame of
vulnerability for depression, suggesting that genetic factors may play a
role in PPD.