Hyperemesis gravidarum Flashcards
Triad of HG (mnemonic):
WED
1. 5% prepregnancy weight loss
2. electrolyte imbalance
3. dehydration
severity of HG scale:
The severity can be assessed using the Pregnancy-Unique Quantification of Emesis (PUQE) score. This gives a score out of 15:
< 7: Mild
7 – 12: Moderate
> 12: Severe
management of HG:
simple measures:
1. rest and avoid triggers e.g. odours
bland, plain food, particularly in the morning
2. ginger
3. P6 (wrist)
4. acupressure
first-line medications
- antihistamines: oral cyclizine or promethazine
- phenothiazines: oral prochlorperazine or chlorpromazine
- combination drug doxylamine/pyridoxine: pyridoxine (vitamin B6) monotherapy is actually used commonly outside of the UK as a first-line treatment for NVP. However, pyridoxine monotherapy is specifically not recommended in the RCOG guidelines
second-line medications
1. oral ondansetron: ondansetron during the first trimester is associated with a small increased risk of the baby having a cleft lip/palate. The Medicines and Healthcare products Regulatory Agency (MHRA) advise that if ondansetron is used then these risks should be discussed with the pregnant woman
- oral metoclopramide or domperidone: metoclopramide may cause extrapyramidal side effects. It should therefore not be used for more than 5 days
mild cases: oral antiemetics managed at home
when should patients with HG be admitted?
- Unable to tolerate oral antiemetics or keep down any fluids
- More than 5 % weight loss compared with pre-pregnancy despite treatment with oral antiemetics
- Ketones are present in the urine on a urine dipstick (2 + ketones on the urine dipstick is significant)
- Other medical conditions need treating that required admission (eg she is unable to tolerate oral antibiotics for a urinary tract infection)
moderate-severe cases of HG (7-12 points on PUQE or >12)
Moderate-severe cases may require ambulatory care (e.g. early pregnancy assessment unit) or admission for:
- IV or IM antiemetics
- IV fluids (normal saline with added potassium chloride as excessive vomiting causes hypokalaemia)
- Daily monitoring of U&Es while having IV therapy
- Thiamine supplementation and folic acid to prevent deficiency (prevents Wernicke-Korsakoff syndrome)
- Antacids to relieve epigastric pain
- Thromboprophylaxis (TED stocking and low molecular weight heparin) during admission (This is due to the combination of pregnancy, immobility and dehydration.)
causes of nausea/vomiting in early pregnancy:
increased levels of beta-hCG:
a)multiple pregnancies
b) trophoblastic disease
c) Down’s syndrome
-nulliparity
-obesity
-family or personal history of NVP
-Smoking is associated with a decreased incidence of hyperemesis.
nausea and vomiting in pregnancy vs HG:
Nausea is a common symptom in pregnancy, particularly early on. Nausea and vomiting in pregnancy starts in the first trimester, peaking around 8 – 12 weeks gestation. The severe form of nausea and vomiting in pregnancy is called hyperemesis gravidarum. Hyper- refers to lots, -emesis refers to vomiting and gravida- relates to pregnancy.
Nausea and vomiting are normal during early pregnancy. Symptoms usually start from 4 – 7 weeks, are worst around 10 – 12 weeks and resolve by 16 – 20 weeks. Symptoms can persist throughout pregnancy.
Hyperemesis gravidarum is the severe form of nausea and vomiting in pregnancy. The RCOG guideline (2016) criteria for diagnosing hyperemesis gravidarum are “protracted” NVP plus:
- More than 5 % weight loss compared with before pregnancy
- Dehydration
- Electrolyte imbalance
A 28-year-old primigravida woman presents to the GP with severe nausea and vomiting. She is 10 weeks’ pregnant with twins and complains of having troublesome morning sickness. She is able to keep fluids down.
On examination, you see a loss of skin turgor and dry skin. Blood tests are sent off and you are awaiting the results.
Given the likely diagnosis, what is the best course of management?
A. Oral promethazine
B. Oral ondansetron
C. Oral chlorpromazine
D. Wrist acupressure
E. Oral metoclopramide
A. Oral promethazine
This patient has presented with hyperemesis gravidarum, defined by the triad of triad of 5% prepregnancy weight loss, dehydration and electrolyte imbalance. The condition affects 1% of pregnancies and is commonly seen at around 8–12 weeks of gestation. It is associated with multiple pregnancies, trophoblastic disease, hyperthyroidism, nulliparity and obesity. Antihistamines should be used first line for women with hyperemesis gravidarum to help control the nausea and vomiting, such as oral promethazine or oral cyclizine.
Not C: chlorpromazine
Oral chlorpromazine is a form of antipsychotic and is not used in hyperemesis gravidarum.
Not B: oral ondansetron
Ondansetron is a second-line medication, less favoured due to an increased risk of the baby having cleft lip/palate if used in the first trimester.
Not E: oral metaoclopramide
Metoclopramide is a second-line medication, as it may cause extrapyramidal side effects in mothers. It should therefore not be used for more than 5 days.
differentials for severe vomiting during pregnancy:
- Infections such as gastroenteritis, urinary tract infection, hepatitis and meningitis
- Gastrointestinal problems: Appendicitis, cholecystitis, bowel obstruction
- Metabolic conditions: Diabetic ketoacidosis, thyrotoxicosis (the term gestational thyrotoxicosis refers to a subset of hyperemetic patients with clinical and biochemical hyperthyroidism in early pregnancy. It is believed to result from circulating hCG with high biological activity. )
- Drug toxicity
- Molar pregnancy (abnormally high levels of beta-hCG due to gestational trophoblastic disease can cause severe nausea and vomiting)
complications of HG:
- Gastrointestinal problems: Mallory-Weiss tears, oesophagitis, malnutrition and anorexia
- Dehydration relating to ketosis and venous thromboembolism
- Metabolic disturbance such as hyponatraemia, Wernicke’s encephalopathy, kidney failure (acute kidney injury), hypoglycaemia
- Psychological sequelae such as depression, PTSD and resentment toward the pregnancy.
- If the condition is very severe, the foetus may be affected due to maternal metabolic disturbance.
- Foetal complications include low birth weight, intrauterine growth restriction and premature labour (severe NVP resulting in multiple admissions and failure to ‘catch-up’ weight gain may be linked to a small increase in preterm birth and low birth weight)
basic investigations for HG:
Bedside:
1. Basic obs
2. Abdominal Examination – look for signs of dehydration, abdominal examination
3. Accurate weight (& height): compare with pre-pregnancy weight (>5% loss significant)
4. Urine dip for ketones
5. PUQE score
Bloods – FBC, U&Es, LFTs, ABG, TFTs, thiamine levels, glucose
Imaging:
- USS to rule out molar pregnancy and multiple pregnancy
Body weight
2. Bloods: Us & Es
3. PUQE score
HG summary
wernicke korsakoff psychosis features (mnemonic)
Wernicke encephalopathy is acute and often reversible while Korsakoff syndrome is chronic and may be irreversible.
