Background
Depressive symptoms during pregnancy can have multiple adverse effects on perinatal outcomes, including maternal morbidity and mortality. The potential impact of antenatal depressive symptoms on maternal health care use, however, has been little explored in low and middle-income countries (LMICs). This paper investigates whether maternal health care utilisation varies as a function of antenatal depressive symptoms.

Methods
In a population-based cross-sectional survey, 1311 women in the second or third trimesters of pregnancy were recruited in Sodo district, Gurage Zone, southern Ethiopia. Depressive symptoms were measured using a locally validated version of the Patient Health Questionnaire (PHQ-9). The association between antenatal depressive symptoms and number of antenatal care (ANC) visits was examined using Poisson regression and the association of depression symptoms with emergency health care visits using negative binomial regression. Binary logistic regression was used to investigate the association of depressive symptoms with initiation, frequency and adequacy of antenatal care.

Results
At PHQ-9 cut off of five or more, 29.5 % of participants had depressive symptoms. The majority (60.5 %) of women had attended for one or more ANC visits. Women with depressive symptoms had an increased risk of having more non-scheduled ANC visits (adjusted Risk Ratio (aRR) = 1.41, 95 % CI: 1.20, 1.65), as well as an increased number of emergency health care visits to both traditional providers (aRR = 1.64, 95 % CI: 1.17, 2.31) and biomedical providers (aRR = 1.31, 95 % CI: 1.04, 1.69) for pregnancy-related emergencies. However, antenatal depressive symptoms were not significantly associated with initiation of ANC.

Conclusions
Increased non-scheduled ANC and emergency health care visits may be indicators of undetected depression in antenatal women, and have the potential to overwhelm the capacity and resources of health care systems, particularly in LMICs. Establishment of a system for detection, referral and treatment of antenatal depression, integrated within existing antenatal care, may reduce antenatal morbidity and treatment costs and promote efficiency of the health care system.