Multiple births and maternal mental health from pregnancy to 5 years after birth: A longitudinal
population-based cohort study
Sammanfattning
Background: There is a lack of population-based studies on multiple births and maternal mental
health. Having a high-risk pregnancy by bearing two or more children is a stressful life event, and the
challenges of parenting two or more children probably also lead to a high level of parental stress.
There are a few results on multiple births and maternal mental health from studies on in vitro
fertilization samples. The only previous cohort study on multiple birth and maternal mental health
included a single measure of depressive symptoms at 9 months postpartum. We aim to estimate the
relative risk for depression and anxiety after multiple birth in a population-based prospective cohort
study while adjusting for factors prior and subsequent to fertilization.
Methods: We used data from 87,807 pregnancies included in the Norwegian Mother and Child Cohort
study. Information on multiple birth was retrieved from the Norwegian Medical Birth Registry, and
maternal mental health was assessed at 17th and 30th week of gestation and 0.5, 1.5, 3, and 5 years
postpartum. There were 1,842 plural births included in the study (i.e. 1,821 twin births and 21 higher
order births). We predicted maternal mental health at each time point, subsequently adjusting for 1)
factors prior to fertilization (e.g. maternal age and in vitro fertilization); 2) factors during pregnancy
(e.g. hypertensive states); 3) factors at delivery (e.g. cesarean section); 4) child-related postnatal
complications (e.g. intracranial hemorrhage); and 5) concurrent depression or anxiety after
pregnancy.
Results: Adjusted for antecedents of plural birth, mothers expecting a plural birth had a normal risk
for anxiety (RR=1.05; 95% CI 0.92-1.20) and depression (RR=1.02; 95% CI 0.89-1.16) at 17th week of
gestation. However, plural birth was associated with maternal depression at 1.5, 3, and 5 years
postpartum and maternal anxiety at 3 years postpartum. The trend was for the association to
increase across time, and mothers of multiplets had a significant higher risk for depression at 5
years (RR=1.77; 95% CI 1.33-2.35). Fully adjusted the RR for depression was 1.51 (95% CI 1.10-2.08).
By adjusting depression for concurrent anxiety, and vice versa we found the effect of multiple
pregnancy to be specific to depression and not anxiety.
Conclusions: Mothers expecting multiplets have normal mental health during pregnancy. After birth
there is an increasing risk for depression up to 5 years of age. Our findings indicate that more is
simply more, and mothers of multiplets have need for additional support several years postpartum