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Nausea and Vomiting in Pregnancy – OSCE Case

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A 26-year-old woman who is currently pregnant with twins attends the early pregnancy antenatal clinic with nausea and vomiting. Work through the case to reach a diagnosis.

UK Medical Licensing Assessment (UKMLA)

This clinical case maps to the following UKMLA presentations:

  • Nausea
  • Normal pregnancy and antenatal care
  • Pregnancy risk assessment
  • Vomiting
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Presenting complaint

“I’ve really been struggling with being sick.”

History of presenting complaint

How far along in your pregnancy are you?

“I am 18 weeks and 3 days today”

How long have you been experiencing nausea and vomiting?

“Almost since I found out I was pregnant at about 8 weeks!

On an average day, for how long do you feel nauseated or sick to your stomach?*

“Almost all day – from when I wake until late in the evening, around 10pm, when I can usually eat prior to falling asleep”

On average in a day, how many times do you throw up?*

“Probably 5-6 times”

On an average day, how many times do you retch or dry heave without throwing anything up?*

“Probably another 5-6 times”

What have you tried to control the nausea and vomiting so far?

“My midwife recommended ginger tea and plain crackers, but that hasn’t helped. My GP prescribed me promethazine and then ondansetron, but I’m struggling to keep these down”

Have you experienced anything like this before?

“In my last pregnancy, my nausea settled by 12 weeks, but this is relentless. With the twins this time, everything is so much more intense…”

Have you experienced any associated symptoms, such as diarrhoea, burning or stinging with urination, or a fever?


*These three questions form the Pregnancy-Unique Quantification of Emesis (PUQE – yes, really) criteria, a validated tool for quantifying the severity of nausea and vomiting in pregnancy.

In addition to a thorough obstetric and gynaecological history, the following areas should be addressed:

How have you been feeling in yourself? How has your mood been?

“I’ve been tired, with a toddler at home and the constant nausea, but otherwise okay. I’m fortunate to have a supportive partner and family.”

Have you started to feel the baby move yet, and if so, have you noticed a pattern?

“I’ve started to feel some flutters, but no strong movements yet.”

Have you noticed any fluid loss or bleeding from down below?

“No, not that I’ve noticed”

Have you experienced any tightenings?

“No, not yet”

Have you noticed any burning or stinging when you pass urine or any abnormal discharge?


Do you have any questions for me?

“Is there anything we can do to make this stop?”

It is also important to consider if a woman could be experiencing intimate partner violence. Unfortunately, for too many women, domestic violence commences or escalates significantly during pregnancy. Although it is generally not necessary to cover this during every routine antenatal visit, it may be appropriate to ask an open-ended question such as “How are things going at home?” to commence this conversation.

Clinical examination

Examination findings


  • HR 82
  • BP 100/65 mmHg
  • Temperature 37.0oC
  • RR 12
  • Oxygen saturation 96% on air
  • Weight – 58kg, from a pre-pregnancy weight of 64kg

Fluid status

  • Dry mucous membranes noted

Abdominal examination

  • Abdomen soft, non-tender (not peritonitic, no flank/suprapubic tenderness)
  • Fundus palpated below the umbilicus (appropriate for dates)
  • Bowel sounds heard 
  • Fetal heartbeat heard, ~155bpm
  • Basic observations, particularly blood pressure
  • Measurement of symphyseal-fundal height from 20 weeks gestation
  • Abdominal palpation to assess fetal lie and presentation
  • Fetal heart auscultation from 12 weeks gestation: this is most commonly done using a handheld Doppler, but in case of twin pregnancy, bedside ultrasound may be required (to ensure both hearts can be visualised separately)
  • Consider checking and recording maternal weight to ensure appropriate weight gain
  • Consider urinalysis, if clinical history is significant for dysuria or any other concerns


Bedside investigations

Laboratory investigations

A CTG is not indicated in this case because of her gestation (<23 weeks); the foetal heart auscultation performed in the physical examination section suffices.

If the patient did not yet have a confirmed intrauterine pregnancy, performing an ultrasound to exclude molar and multiple/higher-order pregnancies would be appropriate.

In cases of refractory nausea and vomiting in pregnancy, it may be appropriate to perform thyroid function tests (to exclude hypo/hyperthyroidism) and lipase (to exclude pancreatitis)

12 weeks

  • Dating ultrasound scan to confirm a viable intrauterine pregnancy and identify higher order/multiple pregnancies, performed at 6-10 weeks
  • Antenatal blood tests, including FBC, iron studies, blood group and screen, rubella +/- varicella immunity, serology for hepatitis B/C + HIV + syphilis, TFTs
  • Urinalysis, microscopy, and culture
  • First-trimester screening (optional), generally either performed as combined first-trimester screening (nuchal translucency ultrasound + PAPP-A, BhCG, blood tests) OR non-invasive prenatal screening + an early anatomy scan

24 weeks

  • Detailed morphology ultrasound scan, typically performed between 18-20 weeks

28 weeks

  • Oral glucose tolerance test, which may be performed from 24 weeks if risk factors for gestational diabetes are present. Local guidelines vary, and some health services may use an alternative test (such as HbA1c) instead
  • Consider repeat FBC, iron studies, blood group, and screen

36 weeks

  • Screening for Group B streptococcus may be offered, although local guidelines vary
  • A third-trimester ultrasound will generally also be recommended (often at ~32 weeks) in women with a low-lying placenta identified at their morphology ultrasound scan


  • Mild or moderate nausea and vomiting in pregnancy
  • Hyperemesis gravidarum
  • Intercurrent infection, such as a UTI or gastroenteritis
  • Diabetic ketoacidosis, in diabetic women
  • Surgical pathologies, such as appendicitis or a small bowel obstruction
  • Drug-induced nausea and vomiting, such as cannabis hyperemesis syndrome

Hyperemesis gravidarum is the most likely diagnosis here. It is diagnosed based on severe, prolonged nausea and vomiting PLUS the triad of dehydration, electrolyte derangement, and more than 5% of pre-pregnancy weight loss.


Investigation results

Random blood sugar

  • 5.4

Bloods [pregnancy-specific reference ranges]

  • FBC: Hb 110 [97-148], Platelets 260 [155-409], WCC 12.3 [5.6-14.8]
  • U&Es: Na+ 132 [129-148], K+ 3.1 [3.3-5.0], Creatinine 50 [35-71]
  • LFTs: ALP 120 [25-126], GGT 14 [4-22], AST 36 [3-33], ALT 37 [2-33]


  • Specific gravity 1.025
  • Positive for ketones (2+)
  • Negative for leukocytes and nitrites
  • Negative for protein

This patient requires admission for management of hyperemesis gravidarum. Her history, particularly her inability to tolerate oral intake despite trialling first and second-line anti-emetics, is concerning. Additionally, her 6kg weight loss represents a loss of ~9% of her pre-pregnancy weight.

The patient’s blood tests are also concerning. She is mildly hypokalaemic and requires electrolyte replacement. She also has mild transaminitis, which can be caused by hyperemesis gravidarum.

The urinalysis, particularly the high specific gravity and ketonuria, are concerning for dehydration. However, it is reassuring that her results do not match a UTI.

Many of these results would be abnormal in a non-pregnant woman of her age (including WCC, Hb, ALP), but are normal in her case due to the normal physiological changes that occur in pregnancy. An excellent guide to these changes can be found here. This highlights why it is essential always to consider pregnancy-specific reference values when assessing pregnant women.

Thiamine supplementation is important in severe nausea and vomiting in pregnancy to prevent the development of Wernicke’s encephalopathy.

Alongside fluid and electrolyte replacement and administration of parental antiemetics, thiamine replacement would form part of this patient’s management. It is particularly important to replace thiamine before administering IV dextrose or nutritional supplementation to avoid precipitating Wernicke’s encephalopathy.


  • Wernicke’s encephalopathy
  • Gastritis and peptic ulcer disease
  • Mallory-Weiss tear and haematemesis
  • Pre-term labour and low birth weight


Dr Jess Speller


  1. Royal College of Obstetricians and Gynaecologists. Green top guideline: The management of nausea and vomiting of pregnancy and hyperemesis gravidarum. Published in 2016. Available from: [LINK]
  2. Perinatology. Normal reference ranges for lab values in pregnancy. Available from: [LINK]


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