Depression in Pregnancy

Women have a lifetime risk of depression of about 1 in 4 and it is most prevalent during their reproductive years. Much emphasis has been placed on the detection and treatment of postnatal depression (due to its morbidity in mother and child), but antenatal depression is actually more frequent, and about half of postnatal depression appears to start antenatally.

Pregnancy and depression inevitably interact:¹

• Pregnancy is a major psychological as well as physiological event:
  • With an excess of chronic life stressors, women may find themselves unable to cope with the additional demands of pregnancy.
  • Many women, particularly those living in poverty or already with many dependent children, will view pregnancy with ambivalence or negative feelings.
  • Issues or memories surrounding poor parenting or abuse women have suffered may reassert themselves and cause distress.
  • Relationships are often under pressure - domestic violence increases during pregnancy.
• Pregnancy-related sex-steroids increase activation of the hypothalamic-pituitary-adrenal axis (the cortisol stress system) which is associated with depression. Some investigators have suggested that high levels of cortisol may effect fetal brain development and be associated with altered temperament and behaviour.²
• Many women stop antidepressant medication due to concerns about potential harm to their developing fetus - this underlies high rates of relapse in pregnancy.³
• Depressed women are more likely to smoke and drink alcohol and less likely to attend for antenatal care - one behavioural pathway mediating poorer obstetric and neonatal outcomes.

Estimates suggest:

• 7% women are depressed outside the perinatal period.
• 7-15% of women in developed countries are depressed in pregnancy compared to 19-25% in economically poorer countries.
• 10% women are depressed postnatally.
• Rates of relapse in pregnant women with a history of recurrent mood disorder may be up to 50%.

Risk factors⁴

Women experiencing social or economic adversity are most likely to experience antenatal depression. Risk factors include:

• History of mood and anxiety disorders
• History of postnatal depression
• History of premenstrual dysphoric disorder
• Family history of perinatal psychiatric illness
• History of childhood abuse
• Poor social support
• Unplanned pregnancy
• Single motherhood
• Large number of existing children
• Domestic violence or marital conflict
• Young age

NICE⁵ advises against using single risk factors to predict individuals at risk of antenatal mental illness but some centres are devising composite scores to identify those at high psychosocial risk.⁶

The signs and symptoms of antenatal depression are as for depression in general. However, if one focuses on somatic symptoms (eg fatigue, insomnia, appetite changes), pregnancy symptoms may mask those of depression, particularly in the first trimester. Thus, the psychological symptoms (eg anhedonia, hopelessness, guilt) may be more reliable during pregnancy.
DSM-IV recognizes postpartum-onset mood disorders but does not refer specifically to depression during pregnancy.

Identifying antenatal depression is potentially difficult - women are reluctant to acknowledge 'difficult' emotions rather than the 'bloom' expected in pregnancy and many of the biological symptoms of depression can also be attributed to the pregnancy itself. NICE guidelines⁵ suggest that health professionals (whether midwives, GPs, health visitors or obstetricians) should screen pregnant women at first contact and at booking with 2 questions:

• During the past month, have you often felt bothered by feeling low, depressed or hopeless?
• During the past month, have you often been bothered by having little interest or pleasure in doing things?

If the woman answers 'yes' to either of the above, then a third question should be asked:

• Is this something you need or want help with?

Use of other self-report measurement tools such as the Edinburgh Postnatal Depression Scale (EPDS), Hospital Anxiety and Depression Scale (HADS) and the Patient Health Questionnaire-9 (PHQ-9) may be helpful in further assessment or for monitoring of response to treatment.

Women with depression and those caring for them need to balance risks to the woman's health and a potential fetus' development:

• The risk to fetus and neonate posted by medication. There appears to be an increased incidence of congenital malformations associated with some psychotropic medications. Since these are such rare events, it is often difficult to confidently quantify the risk or establish causation.
• The risk of untreated mental illness.
• The risk of abrupt cessation of current medication.

Since there is concern about the risk associated with antidepressant use during pregnancy, the threshold for use of psychological treatments is much lower at this time.

Refer women with recurring depression or bipolar disorder at the outset of pregnancy to perinatal psychiatric services for specialist management. Where these are not available, use general psychiatric services.
Guidelines⁵ recommend treatment options dependant on severity of depression, past history of affective disorder and maternal preference. Availability of psychological treatments has obvious implications.

Watchful waiting

Where an individual has had mild depression treated with antidepressants and is pregnant/intends to become pregnant, withdraw the drugs gradually and monitor regularly.

Self help

Suggested for where intervention is required for mild depression. Possibilities include:

• Guided self help
• Computerised cognitive behavioural therapy (C-CBT)
• Exercise⁷

Alternatives, where available, would be non-directive counselling ('listening visits') or brief psychological treatment (usually 4-6 sessions of CBT or IPT).

Interpersonal psychotherapy (IPT) and cognitive behavioural therapy (CBT)

Shown to be effective for milder cases in one small trial, but evidence is extremely limited.⁸ Also time to response is longer than with medication. Psychological treatments may be considered for moderate or severe depression where a woman opts for this in preference to drug treatment or in combination with antidepressant medication.

Antidepressants^9,5

Care is needed in prescribing to women of child-bearing age but with antidepressants consider:

• Tricyclics are considered lower risk than newer antidepressants during pregnancy but have a higher fatal toxicity index than SSRIs.
• Fluoxetine is the SSRI with the lowest risk in pregnancy.
• Imipramine, nortriptyline and sertraline are present in breast milk at relatively low levels whilst citalopram and fluoxetine are present at much higher levels.
• Paroxetine should be stopped if planning a pregnancy or as soon as possible in an unplanned pregnancy as it appears to be most risky amongst antidepressants for congenital malformations, in particular fetal heart development.
• Venlafaxine increases blood pressure during pregnancy and has a higher toxicity in overdose compared to SSRIs and some tricyclics. In general the advice is to avoid mirtazapine, reboxetine, moclobemide or venlafaxine.
• All antidepressants carry the risk of withdrawal or toxicity in the neonate. Normally this is mild and self-limiting.

Antidepressant use is an option in moderate or severe depression or in mild depression that has failed to respond to other measures or with a past history of severe depression.

ECT⁵

Where depression is severe and treatment resistant, strategies include a trial of a different single drug or ECT. Lithium augmentation should be avoided.

Antenatal stress or depression is associated with increased risk of:

• Miscarriage - this may be mediated by antenatal exposure to antidepressants
• Preterm delivery
• Increased pregnancy symptoms, pain relief in labour and worse obstetric outcome¹³
• Low birth weight - may be due to confounding variables¹⁴
• Poor infant growth

Early detection of depression during pregnancy and its adequate treatment is critical to avoid its persistence into the postpartum period and sequelae such as impaired mother-infant attachments and the consequences this has for children. Exposure to tricyclic antidepressants or fluoxetine in pregnancy does not appear to adversely affect cognition, language development, or the temperament of preschool and early-school children whilst maternal depression is associated with less cognitive and language achievement by their children.¹⁵ There is no current evidence to suggest that treatment of antenatal depression alters obstetric and neonatal outcome, however.

Whilst women are at generally low risk of suicide during pregnancy,¹⁶ it is now the most common cause of maternal death in the year following birth in the UK¹⁷ so improving awareness of perinatal mental health problems, in all their diversity, is important.

Women with pre-existing affective disorder

• All women with affective disorders of reproductive age and potential, should have family planning discussed as part of their routine care. Where women with a past history of severe or resistant depression are planning to become pregnant, referral to specialist psychiatric services for pre-conceptual advice is appropriate.
• The decision to stop or continue medication should be an informed decision made by the woman with access to available evidence and risk assessment. Decision making supports can be useful^18,5

Women with depressive symptoms⁵

Where a woman experiences depressive symptoms that do not meet diagnostic criteria but do significantly interfere with her personal or social functioning:

• If she has not had a previous episode of depression, consider increasing social support during pregnancy and the postnatal period with regular informal individual or group based sessions.
• If she has had a previous episode of depression, consider offering brief psychological treatment (4-6 sessions) such as IPT or CBT.