Hyperemesis and NVP

Question 1

Define NVP (SOMANZ)

Answer 1

nausea, vomiting and/or dry retchiing caused by pregnancy, with symptoms commencing in the first trimester without an alternate diagnosis. Severity is based on the PUQE 24 score
mil = 4-6
moderate = 7-12
severe= 13+

Question 2

Define Hyperemesis gravidarum

Answer 2

Nausea and/or vomiting caused by pregnancy leading to significant reduction of oral intake and weight loss of at least 5% compared with pre-pregnancy. With or without:

• dehydration
• electrolyte abnormalities

Question 3

Prevalence of NVP and HG?

Answer 3

~70% NVP

1.1% HG

Question 4

Etiology of NVP and HG?

Answer 4

Genetic predisposition - high incidence first degree relatives. Some genetic/protein abnormalities associated.

H Pylori OR 1.3.

More common female fetus, Asian, low SES, younger, multiple pregnancy

Question 5

Investigations recommended for initial workup for severe NVP or suspected HG?

Answer 5

SOMANZ:

1. Renal function, electrolytes
2. LFTS
3. TFTs
4. Obstetric ultrasound

Other: 
FBC, CRP, blood gas, urine culture and ketone. 
Faecal culture if diarrhoea
H. Pylori antigen. 
Weight

Question 6

When can women with HG/NVP be managed in the community? How often should they be assessed

Answer 6

• PUQE <13
• no other conditions: i.e. T1DM
• not requiring essential oral medications: severe epilepsy, transplant recipient

Review every 1-2 weeks with appropriate titration of therapy.

Question 7

Hyperemesis: Indicators predictive of repeat admission?

Answer 7

gestational age <9w
hospitalisation >2 days
HG during previous pregnancy

Question 8

Indicators for admission with HG or NVP?

Answer 8

• severe electrolyte disturbance
• AKI or renal impairment (creat >90)
• concurrent significant morbidity
• malnutrition/continuing significant weight loss despite therapy, or starvation ketoacidosis
• associated conditions requiring IP management (infection, haematemesis)

Question 9

Criteria for discharge after admission for HG or NVP?

Answer 9

appropriate oral or rectal pharmacotherapy is tolerated
adequate oral nutrition and hydration tolerated
management of concurrent conditions is completed

Question 10

Non-pharmacological interventions for NVP?

Answer 10

small frequent meals low in fat
acupressure P6 (acupressure band for minimum 12 hours per day)
B6
Ginger (RCOG)

Question 11

Principles of holistic management of NVP and HG?

Answer 11

1. interventions to reduce nausea, retching, vomiting
2. management of associated gastric dysmotility
3. Maintenance of hydration, fluid, electrolytes
4. Maintenance of adequate nutrition including provision of vitamins and supplements where required

NB iron and prenatal supplements can exacerbate symptoms. Try to continue iodine or folic acid if possible.

5. psychosocial support
6. monitoring and prevention of side effects and adverse pregnancy and fetal outcomes

Question 12

First line management of mild-moderate NVP?

Answer 12

ginger +/- B6

oral antihistamine + dopamine antagonist

Question 13

Management for moderate-severe NVP or inadequate response to initial treatment?

Answer 13

• IV/IM antihistamine or dopamine antagonist
• excessive sedation or inadequate resonse: add substitute PO/IV serotonin
• add acid suppression therapy

Question 14

Management of refractory NVP or HG?

Answer 14

• consider corticosteroids in addition to other antiemetics

- intensify acid suppression

Question 15

Evidence regarding ondansetron in pregnancy?

Answer 15

Serotonin receptor agonists most effective outside of pregnancy. In pregnancy some studies show metoclopramide equal to ondansetron.

Ondansetron:
Slight increased risk of
- cardiac defects OR 2.0 (1.3-3.1), not replicated in all studies.
- cleft lip, not palate OR 1.6 (1.1-2.3) = additional 3 per 10,000 births.
- renal genesis/dysgenesis (one study only, not replicated)

Question 16

Risk of cleft palate or lip with corticosteroid risk in pregnancy?

Answer 16

Although most teratologists counsel that systemic steroids given in the first trimester may increase the risk of oral clefts, the data remains conflicted, and even the most conservative estimates would quantitate the risk to be only one or two additional cases per 1,000 treated women

Question 17

What is the proposed mechanism of action of ginger and B6 in reduction in nausea and vomiting?

Answer 17

Ginger: weak effect on cholinergic M3 receptors and serotonergic 5HT3 and 5HT4 receptors in the gut. Decreases nausea only.

B6: inhibits H1 receptor, acts on vestibular system. Some inhibition of muscarinic receptors. Decreases nausea only.

Question 18

Dosing of ginger or B6?

Answer 18

Ginger: 250mg QID
B6: 10-25mg QID. Can cause sensory neuropathy. More effective when used with metoclopramide (doxylamine)

Question 19

Evidence for mirtazipine with NVP or HG?

Answer 19

tetracyclic antidepressant. Reduces NVP and depression at 7.5-45mg per day. SE dry mouth and sedation. Limited data suggests no increased risk congenital malformations.

Question 20

Evidence for transdermal clonidine for NVP?

Answer 20

One small study 12 women demonstrated significant improvement with 5mg clonidine patch.

Question 21

Obstetric complications associated with HG?

Answer 21

low birth weight OR 1.42 (1.27-1.58)
SGA OR 1.28 (1.02-1.6)
preterm birth OR 1.32 91.04-1.68)
preterm PET OR 2.09 (1.38-3.16)
placental abruption RO 3.07 (1.88-5.00)

some evidence indicates childhood impaired insulin sensitivity.