Hyperemesis Gravidarum

Question 1

What is hyperemesis gravidarum?

Answer 1

Extreme form of nausea and vomiting

Question 2

It occurs in what percentage of pregnancies?

Answer 2

1%

Question 3

What is it thought to be due to?

Answer 3

Raised beta hCG levels

Question 4

Between what weeks of pregnancy is it most common?

Answer 4

8-12 weeks, but may persist up to 20

Question 5

What is it associated with?

Answer 5

Multiple pregnancies 
Trophoblastic disease
Hyperthyroidism 
Nulliparity 
Obesity

Question 6

What is associated with a decreased incidence of hyperemesis?

Answer 6

Smoking

Question 7

What symptoms occur?

Answer 7

Severe dehydration 
Deranged bloods
Marked ketosis
Weight loss
Nutritional deficiency

Question 8

When does NICE suggest that admission should be considered?

Answer 8

Continued nausea and vomiting, unable to keep down liquids or oral antiemetics
Continued nausea and vomiting with ketonuria and or weight loss > 5% body weight despite treatment with oral antiemetics
A confirmed or suspected comorbidity e.g unable to tolerate oral antibiotics for UTI
Lower threshold for admission if coexisting condition e.g DM

Question 9

The RCOG recommend what triad is present before diagnosing hyperemesis gravidarum?

Answer 9

5% pre pregnancy weight loss
Dehydration
Electrolyte imbalance

Question 10

How can the severity be classified?

Answer 10

The pregnancy-Unique Quantification of Emesis score

Question 11

What investigations should be done?

Answer 11

Urine dip - ketones, UTI
FBC - haematocrit 
U and E - dehydration and hypokalaemia 
LFT and amylase (raised ALT common in excessive vomiting in pregnancy) 
TFTs
USS - exclude GTD/ multiple pregnancy

Question 12

Why is there a thyrotoxicosis like picture?

Answer 12

The alpha subunit of hCG is the same as in TSH

Question 13

What differentials should be considered?

Answer 13

UTI - common in pregnancy that patient doesn’t have typical symptoms of UTI
Gastroenteritis
Appendicitis
Pancreatitis
Thyrotoxicosis
Tumours - giving positive pregnancy test, but patient not pregnant e.g teratoma, germ cell tumours, islet cell tumour, choriocarcinoma
Hydatidiform mole

Question 14

How is it managed?

Answer 14

Rehydration- not with glucose, replace potassium
Thiamine replacement and folic acid
Antihistamines first line (promethazine) or cyclizine, second line: ondansetron and metaclopramide
Ranitidine- especially if evidence of Mallory Weiss tear
Consider thromboprophylaxis if severe dehydration
Steroids - stimulate appetite
Rare cases: TPN/JEG, termination

Question 15

Why should rehydration not include glucose?

Answer 15

Can precipitate Wernicke’s encephalopathy

Question 16

What complications can occur?

Answer 16

Wernicke’s encephalopathy 
Mallory Weiss tear 
Central pontine myelinolysis
Acute tubular necrosis 
Fetal: small gestational age, pre term birth