Managing anorexia nervosa is a challenging area of mental health, requiring a multidisciplinary team approach to ensure both physical and mental health are considered as part of assessment, management and recovery. Anorexia nervosa is an eating disorder characterised by restriction of intake and low body weight, intense fear of weight gain and disturbance in body image. It can be associated with restricting and/or binging and purging behaviours. Body mass index (BMI) determines disease severity, with a BMI of 17–20 considered mild, 16–17 moderate, 15–16 severe and less than 15 extreme. It had been thought, for pregnancy to occur, AN needed to be in remission. However, this is not always the case. Unlike depression, anxiety and psychotic disorders, there is little guidance and research into anorexia nervosa and pregnancy. The most recent Australian National Guidelines for Perinatal Mental Health provide no mention of the assessment and management of eating disorders in pregnancy.¹

Case description

The patient was a 30-year-old G2P1 transferred from a tertiary general hospital to the maternal-fetal medicine unit of a tertiary O&G hospital at 24 weeks gestation. Transfer occurred to facilitate the ongoing management of her complex obstetric care. This entailed intensive multidisciplinary team involvement, including maternal-fetal medicine, midwifery, psychiatry, physician and dietetics weekly to fortnightly review.

The patient had a 15-year history of AN for which she had received minimal treatment in the past. Following the diagnosis of her second pregnancy, she was booked into a maternity service within a tertiary general hospital. Her antenatal care appeared unremarkable, despite noting her low BMI of 15 at the booking visit. Following the routine administration of the Edinburgh Postnatal Depression Scale (EPDS), she was referred for a mental health consultation at 20 weeks gestation. At this psychiatric consultation, it was recognised that her BMI remained low at 17, she had active symptoms throughout her pregnancy associated with anorexia nervosa, had insufficient weight gain over the 20 weeks of pregnancy, and had significantly lowered mood with associated risk. On physical examination, she had significant postural tachycardia, resting bradycardia, and postural symptoms. She had been restricting her dietary intake to well below normal requirements. She described purging up to twice daily with binging behaviour around three times per week. She did not use laxatives, exercise excessively or engage in other compensatory behaviours. She feared weight gain, with her self-worth heavily influenced by her body weight.

The patient also presented with significant depressive symptoms characterised by pervasively low mood, irritability, demotivation, low energy, initial insomnia, passive suicidal ideation, and feelings of being generally overwhelmed and unable to cope. She described long-standing generalised anxiety characterised by excessive worry. Her personality construct was notable for self-criticism and a focus on achievement. She did not meet the diagnostic criteria for any other mood, anxiety, trauma-based or psychotic disorder.

The patient’s eating disorder commenced when she was in her teenage years during a period of significant stress for her family. Strict restriction of her dietary intake gave her a sense of control when she otherwise felt helpless.

The patient had previously seen a psychiatrist, but had no recent contact with mental health services. She had never had an inpatient psychiatric admission and never received any intensive eating disorder treatment. She was previously trialled on fluoxetine once and found this helpful. There was no history of suicide attempts. Drug and alcohol assessment was unremarkable. There was a family history of both anxiety and depression.

Following her initial assessment by a psychiatrist, she was admitted to a general medical ward for 23 days where her physical health was stabilised. Hypokalaemia (2.7mmol/L) was present on the admission bloods. She received nasogastric tube (NGT) continuous feeds initially, with gradual progression to bolus feeds. Re-feeding syndrome was evident with the development of hypophosphataemia on re-feeding requiring replacement. Initial attempts to transition from nasogastric to oral intake were complicated by hypoglycaemia, with eventual successful introduction of meals and full diet. Unstable calcium levels were monitored and corrected throughout the admission.

Given the concerns about prolonged low weight over her pregnancy, with associated physiological and electrolyte disturbances and the potential effects on the fetal growth, her care was transferred to a tertiary women’s hospital with a maternal-fetal medicine unit. She was initially assessed as an inpatient and then discharged for weekly review. At each review, she was seen by obstetrics, midwifery, psychiatry, physicians and dietetics, with close collaboration between all of those involved in her care. Despite initial concerns expressed about the distance from home, the patient’s overall attendance at the antenatal clinic was very reliable.

Her obstetric history included an uncomplicated, term spontaneous vaginal delivery two years earlier of a 3.8kg baby. Routine antenatal investigations were all normal, including a low probability first trimester screen and an unremarkable second trimester morphology ultrasound.

Electrolyte studies throughout the pregnancy were normal following removal of the nasogastric tube at 24 weeks gestation. Low albumin, low total protein and low calcium levels were treated with oral supplementation and were well tolerated, with improvement to near normal ranges by the end of pregnancy.

Her tendency to restrict dietary intake appeared greatest during times of increased psychosocial stress. Serial growth scans of the fetus revealed plateauing fetal growth between the 26th and 28th gestational week, with the abdominal circumference falling from the 50th to the 10th centile. This correlated with a period of increased stress in the family environment, an associated reduction in clinic attendance and lack of weight gain. As maternal nutrition improved in the third trimester, abdominal circumference continued to track along the 10th centile with reassuring fetal Doppler studies.

The patient was provided with extensive psycho-education around the potential risks associated with restricted dietary intake on the developing fetus. Sertraline was up-titrated to 150mg, with good effect on depressive and anxious symptomatology. Towards the end of her pregnancy, she was further engaged with a perinatal clinical psychologist to facilitate treatment and support in the postpartum period.

Throughout the pregnancy, she reported anxiety around meal times and the occasional desire to purge, particularly related to the bodily sensations of nausea, bloating and fullness. These sensations were exacerbated during the latter part of the third trimester, with subsequent lack of maternal weight gain after 34 weeks gestation. In view of this, the patient was admitted for a two-day inpatient stay at 37 weeks gestation. The admission provided an opportunity to ensure physiological stability and optimised nutritional intake in preparation for delivery. Electrolyte and ECG monitoring were all unremarkable, with ongoing hypocalcaemia and low, but acceptable blood sugar levels recorded. A maternal ECG in the late third trimester was performed to ensure cardiac function would support vaginal delivery and reassuringly showed normal ventricular size and function.

An uncomplicated induction of labour occurred at 38+2 weeks of gestational age and the patient had a spontaneous vaginal delivery of a live male infant weighing 3.2kg (35th centile). She was assessed prior to delivery and postpartum by the mental health team. After discharge, she was supported with 10 days of midwifery group practice home visits. Two weeks after discharge, she was reviewed by a psychiatry and midwifery team at the hospital. She was well, reported no symptoms of depression or anxiety, had stable weight and her baby was thriving. She had commenced but then ceased breastfeeding, however, she felt supported by her visiting midwife in this decision. She also felt well equipped with adapting plans from dietetics around her diet and nutritional intake. Her postpartum follow up will include general practice, psychiatry, clinical psychology and dietetics.

Discussion

Anorexia nervosa in pregnancy is uncommon, with prevalence estimates from the UK and Norway at 0.05–0.5 per cent of pregnant women.² However, despite a low prevalence, there have been several large studies that have confirmed increased risks in pregnancy for women with eating disorders. For women with anorexia nervosa, this has included associations with slower fetal growth, low birth weight and small for gestational age, lower Apgar scores, and higher risk of neonatal resuscitation and perinatal death.³ Furthermore, poorer growth in offspring have been shown to continue across the first year of life.⁴ Anorexia nervosa is associated with a higher rate of depression and anxiety, including perinatal depression, and is also associated with low rates of breastfeeding.^{5 6}

This case report illustrates the risk of untreated anorexia nervosa on maternal morbidity and the potential for impact on fetal growth. Equally, it illustrates that with a coordinated approach across the key disciplines, a good outcome for mother and infant was able to be achieved. This positive outcome was not only pregnancy and neonatal parameters, but equally mental health, with a remission of depression and anxiety symptoms and a growing awareness and commitment to treatment for her eating disorder. This case also illustrates that beyond these tangible clinical outcomes was the less measurable, but equally important, aspects of engagement, support and collaborative care. This brought together a team that drew on expertise in midwifery care, maternal fetal medicine, obstetric medicine, dietetics and perinatal mental health.

Conclusion

In managing a pregnant woman with anorexia nervosa, there are key principles.[/note]Galbally M, Snellen M, Lewis A. Psychopharmacology and Pregnancy: Springer; 2016.[/note] These include:

• Ensuring there is a mental health referral to assess both the eating disorder, co-morbidity of depression and anxiety and also any impact on the developing relationship with the fetus/infant
• Regular monitoring of electrolytes, particularly for active purging behaviours
• Regular growth monitoring of the fetus, particularly for active restrictive behaviours
• Maternal ECG prior to delivery if there are concerns that an eating disorder has impacted on cardiac function
• Ensuring coordination of multidisciplinary care, including obstetrics, midwifery, mental health, dietetics and, when necessary, obstetric medicine
• Having a clear threshold for admission based on parameters of maternal health and fetal wellbeing that are likely to be affected by an eating disorder, which include maternal hypoglycaemia, bradycardia, Long QT syndrome, restrictive cardiac failure from cardiac atrophy, bone marrow dysfunction, especially neutropenia etc
• Long-term health, including assessing for peripartum osteopenia/osteoporosis.

1. Austin M-P, Highet N, Expert Working Group. Mental health care in the perinatal period: Australian Clinical Practice Guideline 2017. Guideline. In: Excellence CoP, editor. Melbourne 2017.
2. Watson H, Torgersen L, Zerwas S, et al. Eating disorders, pregnancy and the postpartum period: Findings from the Norwegian Mother and Child Cohort Study (MoBa). Norwegian Journal of Epidemiology 2014;24(1-2):51.
3. Linna M, Raevuori A, Haukka J, et al. Pregnancy, obstetric and perinatal health outcomes in eating disorders. American Journal of Obstetrics and Gynecology 2014;211(4):392.e1-.e8.
4. Perrin E, Von Holle A, Zerwas S, et al. Weight-for-length trajectories in the first year of life in children of mothers with eating disorders in a large Norwegian cohort. International Journal of Eating Disorders 2015;48(4):406-14.
5. Galbally M, Snellen M, Lewis A. Psychopharmacology and Pregnancy: Springer; 2016.
6. Ward V. Eating disorders in pregnancy. BMJ. 2008;336(7635):93-6.