Review Journal that Using Secondary Data Analysis: Pregnancy Intention and Postpartum Depression: Secondary Data Analysis from A Prospective Cohort

Review or Commentary on ‘Pregnancy intention and postpartum depression: secondary data analysis from a prospective cohort’      Secondary data refers to data that was collected by someone other than the user. Common sources of secondary data for social science include censuses, information collected by government departments, organisational records and data that was originally collected for other research purposes. Primary data, by contrast, are collected by the investigator conducting the research.      Secondary data analysis can save time that would otherwise be spent collecting data and, particularly in the case of quantitative data, can provide larger and higher-quality databases that would be unfeasible for any individual researcher to collect on their own. In addition, analysts of social and economic change consider secondary data essential, since it is impossible to conduct a new survey that can adequately capture past change and/or developments. However, secondary data analysis can be less useful in marketing research, as data may be outdated or inaccurate. Secondary data can be obtained from different sources: ·  information collected through censuses or government departments like housing, social security, electoral statistics, tax records ·     internet searches or libraries ·     progress reports      During pregnancy and early motherhood women have an increased risk of depression, which remains a significant contributor to maternal death rates in the UK (Oates, BJOG 2011;118:134–41). Postnatal depression (PND) is a form of clinical depression and includes symptoms of fatigue, diminished interest and pleasure in activities, social withdrawal, sadness and hopelessness in the period following childbirth. The problem of PND is widespread, and it is estimated that one in ten women will be affected by depression during any month in the first year after giving birth (Gavin et al., Obstet Gynecol 2005;106:1071–83).The consequences of depression during the postpartum period are not limited to the mother alone and it can lead to difficulties in mother–infant bonding, relationships and child development.   A number of risk factors for PND have been studied in efforts to improve identification, prevention and treatment for women at risk. The findings of this study highlight that pregnancy intention may be an important contributing factor to postnatal maternal depression, with unintended or unwanted pregnancies resulting in a three- to five-fold increase in risk. Interestingly, although for most women the risk of depression decreases over the first postnatal year, the authors report a higher risk at 12 months postpartum for women with unintended pregnancies and an increase in risk over time for women with an unwanted pregnancy. This emphasises that women who have unintended pregnancies may have a specific risk for more protracted depression following childbirth and require more long-term monitoring and treatment.   One of the strongest predictors of PND is a history of depression, and over 50% of women who experience depression during or following pregnancy are likely to have had an episode of depression in the 9 months before pregnancy (Dietz et al., Am J Psychiatry 2007;164:1515–20). However, many studies fail to measure mothers’ prenatal depression and therefore lack the ability to determine whether postnatal episodes of depression represent new onsets of depression or continuations of previous episodes. In this study, the absence of a measure of prepregnancy depression reduces the certainty of the directionality of the association between postpartum depression and unintended pregnancy, because women who are depressed may also be more likely to have an unintended pregnancy. Further studies of perinatal depression should endeavour to account for pre-existing depression as well as potential social patterning of PND in women with unintended pregnancies.    Nevertheless, given that unintended pregnancy is a likely risk factor for depression, awareness that a pregnancy was unintended should further prompt clinicians to screen for depression both during and after pregnancy. Approximately 50% of pregnancies are reported to be unintended and further research is warranted to determine the benefits of routine enquiries about pregnancy intention at antenatal visits.