Psychiatric disease has been identified as a risk factor for adverse obstetric and neonatal outcomes, and suicide remains a leading cause of direct maternal death in the reports of the Confidential Enquiries into Maternal Deaths. As well as women with pre-existing psychiatric disease, it is estimated that 10-15% of mothers suffer from postnatal depression, and as many as 60% experience postnatal ‘blues’. The risk of admission to hospital with psychosis in the first 3 months after childbirth is more than 300 times greater than at other times.
Much of the challenge in providing effective care to women with psychiatric disease relates to the organisation and funding of services, and the identification of women at risk. Thus there is emphasis on attempting to identify women with a past history of mental illness antenatally, and routine screening questions on booking should include past history and risk factors, including family history. The anaesthetist’s involvement is usually restricted to caring for women who present peripartum or who have attempted suicide.
Problems and special considerations
Pre-existing psychiatric disease
Patients may be taking drugs that are affected by pregnancy, that have important maternal or fetal effects, or that affect anaesthesia. Women with bipolar disorder may be maintained on lithium or, less commonly, carbamazepine. Serial monitoring of plasma drug levels is particularly important for these drugs. Lithium may potentiate neuromuscular blockade (with both suxamethonium and non-depolarising neuromuscular blocking drugs). Women with schizophrenia are likely to be taking a variety of antipsychotic drugs, high doses of which can cause sedation and postural hypotension due to а-blockade. The latter is likely to be exacerbated by the physiological changes of pregnancy. Monoamine oxidase inhibitors (MAOIs) have a number of potential interactions, the most important of which concern pethidine and vasopressors. In addition, maternal anticonvulsant therapy may cause neonatal vitamin K deficiency, which may be associated with adverse effects such as haemorrhagic disease of the newborn. Some studies have suggested a link between untreated depression and hypertensive disease of pregnancy, an increased risk of bleeding or need for operative delivery.
Women who have been psychiatrically well and taking maintenance drugs may stop their medication when they become pregnant and present with recurrence of symptoms.
Many of the psychotropic drugs are relatively contraindicated during pregnancy, but a risk-benefit analysis must be made before changing or stopping such medication.
Women with psychiatric disease may lack capacity to give consent to treatment (see below). In acute mental states, they may also refuse treatments, disrupt the care of other patients and not follow feeding policies.
Postnatal psychiatric disease
Women who develop postnatal depression may not have had any warning symptoms or signs. Women with a past history of psychiatric disease or drug dependence may conceal this from obstetricians and midwives because of the perceived stigma of these conditions. Those with a previous history of postnatal depressive psychosis run a 50% risk of recurrence, classically at the same time postnatally as before. It is important for all healthcare professionals to maintain a high level of awareness of such disorders, and to ask all women at booking about previous psychiatric illness.
Substance abuse
Drug abuse is more common in North America than in the UK, but nevertheless it is an important cause of morbidity and mortality in the UK (see Chapter 147, Substance abuse). Mothers may conceal their use of recreational drugs, as they may feel that they will be judged, or for fear of being reported to the police or to child protection agencies. Liaison between the general practitioner, social services and maternity services is required.
Management options
Antenatal care
Women with poorly controlled psychiatric disease may default from antenatal care and may thus be at increased risk from undetected complications of pregnancy. They may exhibit hospital phobia and may lack insight into the need for medical care if pregnancy-related problems occur. Continuity of care, which enables a trusting relationship to be developed with one or two healthcare professionals, is vital. A perinatal mental health plan must also be in place and should be accessible to all healthcare professionals who provide care for the woman.
Antenatal discussion about the options for analgesia in labour and the possibility of needing anaesthesia for operative delivery is particularly important, and such discussions should be documented and witnessed by the woman’s partner, and a third party if possible. There must be discussion between the psychiatrist, obstetrician, general practitioner and the woman herself about continuing drug therapy throughout pregnancy. Women who are maintained on drug therapy should be monitored regularly to ensure that the pregnancy- related increase in blood and plasma volume does not result in subtherapeutic drug levels.
Labour and delivery
Regional analgesia and anaesthesia are not contraindicated for women with psychiatric disease. Women with untreated or poorly controlled depression may subjectively experience more intense pain in labour and may therefore have an increased need for epidural analgesia.
Women taking an MAOI can receive ephedrine or phenylephrine to correct hypotension caused by regional anaesthesia, but smaller doses than usual should be used, as pressor responses may be exaggerated. Pethidine should be avoided, but fentanyl and morphine have both been used uneventfully.
There is a need for a high level of awareness among all healthcare professionals involved in intrapartum and postnatal care. Symptoms and signs suggestive of depressive illness must be treated promptly. Tri- and tetracyclic antidepressants, the selective serotonin reuptake inhibitor group of antidepressants and MAOIs may all be necessary in the treatment of both non-pregnancy-related and postnatal depression. Electroconvulsive therapy may also be indicated.
Women known to abuse illegal drugs should be treated with particular care. There are numerous interactions with medical drugs, and women frequently abuse multiple drugs.
Consent
A psychiatrist’s input may be invaluable in characterising a psychiatric patient’s illness and advising on her state of mind, though the decision on whether she has capacity should be made by the treating doctor, after considering such advice (see Chapter 169, Consent). The doctrine of necessity allows treatment to be administered without consent if she does not have capacity and this is in the patient’s best interests, but it cannot be assumed that what the obstetric team would wish to do always reflects the mother’s ‘best interests’, and a psychiatrist’s advice maybe useful here too. In the UK, the unborn fetus has no legal status or rights (though it may have moral ones).
If the mother is held in hospital under the Mental Health Act (1983), this only covers treatment of the primary mental condition and does not allow other treatments to be enforced unless they are considered to affect that condition directly.
Patients in whom consent may be problematic require multidisciplinary discussion antenatally in order to formulate a management plan. Often there is extensive discussion but the obstetric anaesthetist is not invited, so that the first contact he/she has may be when analgesia or anaesthesia is required.
Key points
• Psychiatric disease is common in pregnancy.
• A patient’s drug therapy requires careful monitoring during and after pregnancy.
• The possibility of substance abuse should always be considered.
• Difficulties with consent should be anticipated and plans made in good time.
Further reading
Cantwell R, Knight M, Oates M, Shakespeare J, on behalf of the MBRRACE-UK mental health chapter writing group. Lessons on maternal mental health. In Knight M, Tuffnell D, Kenyon S, et al.;
MBRRACE-UK. Saving Lives, Improving Mothers’ Care: Surveillance of maternal deaths in the UK 2011-13 and lessons learned to inform maternity care from the UK and Ireland Confidential Enquiries into Maternal Deaths and Morbidity 2009-13. Oxford: National Perinatal Epidemiology Unit, University of Oxford, 2015, pp. 22-41.
Gadot Y, Koren G. The use of antidepressants in pregnancy: focus on maternal risks. J Obstet Gynaecol Can 2015; 37: 56-63.
National Institute for Health and Care Excellence. Antenatal and Postnatal Mental Health: Clinical Management and Service Guidance. Clinical Guideline 192. London: NICE, 2014 (updated April 2018). www.nice.org.uk/guidance/cg192 (accessed December 2018).
Royal College of Obstetricians and Gynaecologists. Management of women with mental health issues during pregnancy and the postnatal period. Good Practice 14. London: RCOG, 2011. www .rcog.org.uk/en/guidelines-research-services/guidelines/good-practice-14 (accessed December 2018).