#189 Nausea and Vomiting of Pregnancy Flashcards
What is the prevalence of nausea during pregnancy? Vomiting and retching?
Nausea 50-80%
Vomiting and retching 50%
What is the recurrence rate of nausea and vomiting in subsequent pregnangies?
15-81%
What clinical score/index is there for nausea and vomiting of pregnancy that the score is associated with quality of life measures?
Pregnancy-unique quantification of emesis and nausea (PUQE)
Can early treatment of nausea and vomiting of pregnancy help prevent progression to hyperemesis gravidarum?
It may be beneficial
What questions are asked on the pregnancy-unique quantification of emesis and nausea assessment?
On average day, how long do you feel nauseated or sick to your stomach? On average day, how many times do you vomit? On average day, how many times do you have dry heaves?
What is the diagnostic criteria for hyperemesis gravidarum?
No single accepted definition exists. Clinical diagnosis of exclusion. Most common criteria: persistent vomiting not related to other causes, measure of acute starvation (large ketonuria), discrete measure of weight loss (usually at least 5% of prepregnancy weight)
What lab abnormalities might be seen in patient with hyperemesis gravidarum?
Electrolyte abnormalities, biochemical hyperthyroidism (low TSH, increased thyroxine), elevated liver enzymes (usually <300units/L), increased bilirubin (<4mg/dL), serum amylase or lipase (up to 5x normal levels)
What is the incidence of hyperemesis gravidarum?
Approximately 0.3-3% of pregnancies
What is the most common indication for admission to the hospital during first trimester?
Hyperemesis gravidarum
When does nausea and vomiting of pregnancy typically start?
Almost always before 9wks. Need to consider other etiologies if after 9wks
What GI conditions should be considered in the differential diagnosis of nausea and vomiting of pregnancy?
Gastroenteritis, gastroparesis, achalasia, biliary tract disease, hepatitis, intestinal obstruction, peptic ulcer disease, pancreatitis, appendicitis
What conditions should be considered in the differential diagnosis of nausea and vomiting of pregnancy related to the GU tract?
Pyelonephritis, uremia, ovarian torsion, kidney stones, degenerating uterine leiomyoma
What metabolic conditions should be considered in the differential diagnosis of nausea and vomiting of pregnancy?
Diabetic ketoacidosis, porphyria, Addison’s disease, hyperthyroidism, hyperparathyroidism
What neurologic conditions should be considered in the differential diagnosis of nausea and vomiting of pregnancy?
Pseudotumor cerebri, vestibular lesions, migraine headaches, tumors of the CNS, lymphocytic hypophysitis
What pregnancy-related conditions should be considered in the differential diagnosis of nausea and vomiting of pregnancy?
Acute fatty liver of pregnancy, preeclampsia
What theories of the etiology of nausea and vomiting have been proposed?
Hormonal stimulus (hcg and estrogen), evolutionary adaptation and psychologic predisposition
What hormones are though to be associated with nausea and vomiting of pregnancy?
hcg and estrogen
How does cigarette smoking affect the levels of hcg and estradiol during pregnancy?
Lower levels of both
How does cigarette smoking affect the risk of a woman to get hyperemesis gravidarum during pregnancy?
Decreases the risk (postulated due to decreased levels of hcg and estradiol)
Is there an association between women who have nausea and vomiting after estrogen exposure (eg high dose OCP taper) and risk of nausea and vomiting of pregnancy?
Yes. Those with n/v after estrogen exposure have increased risk of nausea and vomiting of pregnancy
What underlying psychiatric condition is associated with increased risk of hyperemesis gravidarum?
None! Evidence that n/v of pregnancy is caused by a conversion disorder or an abnormal response to stress is “questionable at best”
What are risk factors for development of hyperemesis gravidarum?
Increased placental mass (eg, advanced molar gestation, multiple gestation), history of motion sickness, migraine headaches, family history, personal history in prior pregnancy
What significant morbidities can be caused by nausea and vomiting of pregnancy?
Wernicke encephalopathy, splenic avulsion, esophageal rupture, pneumothorax, and acute tubular necrosis
What causes Wernicke encephalopathy?
Vitamin B1 deficiency
True or false, nausea and vomiting of pregnancy has led women to terminate a pregnancy?
True
Does mild to moderate vomiting during pregnancy affect the embryo/fetus?
Little apparent effect on pregnancy outcome
Does nausea and vomiting of pregnancy or hyperemesis gravidarum have association with rates of miscarriage?
Associated with lower rates of miscarriage
Is there an association between hyperemesis gravidarum and congenital anomalies?
No significant association
Is hyperemesis gravidarum associated with higher incidence of low birth weight and SGA infants?
Yes, according to a systematic review and meta-analysis
Is hyperemesis gravidarum associated with higher risk of premature infants?
Yes, according to a systematic review and meta-analysis
Is hyperemesis gravidarum associated with increased risk of perinatal or neonatal mortality?
No, according to large retrospective cohorts
How should you advise women with nausea and vomiting of pregnancy or hyperemesis gravidarum regardingpregnancy outcome?
Appropriate to reassure that the presence of these conditions most often portends well for pregnancy outcomes
What can be done prior to onset of nausea and vomiting of pregnancy to help prevent its occurrence?
Taking multivitamin at time of fertilization. Two studies found that those taking multivit at time of fert were less likely to need medical attention for vomiting
What dietary recommendations can be made to try and ameliorate nausea/vomiting of pregnancy?
Frequent, small meals. Avoiding spicy or fatty foods; eliminating supplemental iron and substituting folic acid for iron-containing prenatals. Eating bland or dry foods, high-protein snacks, crackers in AM. Intake of ginger (studies show improvement in nausea, not vomiting)
Are acupressure, acupuncture, or electrical nerve stimulation shown to improve nausea and vomiting in pregnancy?
Most studies report benefit, but many have significant flaws. Two largest, best-designed studies showed now benefit. Two systematic reviews found limited benefit with P6 accupressure but no benefit in P6 acupuncture or nerve stim.
True or false, better to treat n/v of pregnancy earlier rather than wait for resolution?
True, risk that n/v could progress to hyperemesis gravidarum.
What are all the delivery options for antiemetics?
oral, IV, rectal suppository, oral dissolvable tablet, transdermal patch, continuous subcutaneous microinfusion pumps (11-31% of patients with pumps had adverse effects)
What is the concern of parallel use of a dopamine antagonist and phenothiazine meds for nausea?
Increased risk of extrapyramidal effects (eg tardive dyskinesia) or rarely neuroleptic malignant syndrome
- dopamine antagonist (metoclopramide)
- phenothiazine (eg, promethazine, prochlorperazine, chlorpromazine)
What are signs and symptoms of neuroleptic malignant syndrome?
high fever, confusion, rigid muscles, and symptoms of autonomic nervous system instability. Life-threatening reaction.
What is the concern of parallel use of serotonin 5-HT3 inhibitors and phenothiazine meds for nausea?
Potential cardiac risk of QT interval prolongation.
- Serotonin 5-HT3 inhib = ondansetron
- phenothiazine (eg chlorpromazine)
What is first line therapy for nausea and vomiting of pregnancy?
Nonpharmacologic options: convert PNV to folic acid supplement, ginger capsules 250mg 4x/day, consider P6 acupressure with wrist bands
What are first line pharmacologic option(s) for nausea and vomiting of pregnancy?
Vitamin B6 (pyridoxine) 10-25mg PO w/ or w/o doxylamine 12.5mg PO, 3-4x/day.
OR
Vit B6 + Doxylamine 10mg/10mg two tabs oral qHS, up to 4 tabs per day (one in AM, one midday, two PM)
OR
vit B6 + doxylamine 20mg/20mg qHS. Up to 2 tabs per day, morning and bedtime.
What is the next step in management of nausea and vomiting of pregnancy if no improvement with vitamin b6 + doxylamine?
Add the following:
Dimenhydrinate (dramamine) 25-50mg q4-6h PO (max 200mg/day if also taking doxylamine)
OR
Diphenhydramine (benadryl) 25-50mg PO q 4-6h
OR
Prochlorperazine (compazine) 25mg q12h rectally
OR
Promethazine (phenergan) 12.5-25mg q4-6h, PO or PR
What is the next step in management of nausea and vomiting of pregnancy if no improvement w/ no dehydration with vit B6 + doxylamine in addition to dimenhydrinate or diphenhydramine or prochlorperazine or promethazine?
Add any of the following: Metoclopramide, 5-10mg q6-8h PO or IM OR Ondansetron 4mg PO q8h OR Promethazine 12.5-25mg q4-6h PO, PR, or IM OR Trimethobenzamide 200mg q6-8h, IM
What is the next step in management of nausea and vomiting of pregnancy, failing initial nonpharmacologic and pharmacologic management presenting with dehydration?
IV fluid replacement (thiamine IV 100mg initially and 100mg daily for next 2-3 days for women have vomited for more than 3 weeks). Add any of following: Dimenhydrinate, 50mg IV q4-6h OR Metoclopramide 5-10mg q8h IV OR Ondansetron 8mg q12h IV OR Promethazine 12.5-25mg q4-6h IV
What is next step in management for patient with nausea and vomiting, failed outpatient therapy, s/p IVF hydration and IV dimenhydrinate or metoclopramide or ondansetron or promethazine?
Add the following:
Chlorpromazine 25-50mg IV or IM q4-6h or 10-25mg PO q4-6h
OR
Methylprednisolone 16mg q8h PO or IV for 3 days. Taper over 2 wks, lowest effective dose. Limit total duration to 6wks.
What is a common side effect of taking a vitamin B6 and doxylamine combined medication?
CNS affects (sleepiness, tiredness, or drowsiness) in 28%
Is metoclopramide linked to increased risk of congenital malformations?
No
Between promethazine and metoclopramide, which is more effective at treating hyperemesis gravidarum and which has more side effects?
Similar efficacy at 24 hours. Promethazine had higher rates of drowsiness, dizziness, and dystonia
What are adverse effects of dopamine antagonists used for treating nausea and vomiting of pregnancy?
Dry mouth, drowsiness, dystonia, and sedation
What are common adverse events in using antihistamines for treatment of nausea and vomiting of pregnancy?
Sedation, dry mouth, lightheadedness, and constipation
What are the risks to the fetus of taking antihistamines for n/v during pregnancy?
No association with birth defects
Is ondansetron or metoclopramide more efficacious in treating hyperemesis gravidarum?
Similar efficacy
Is ondansetron or vitamin B6 plus doxylamine better at controlling nausea and vomiting?
Ondansetron was more effective in small double-blind RCT
What are common adverse effects of ondansetron?
Headache, drowsiness, fatigue, and constipation. Can prolong QT interval
For which patients taking ondansetron should you be concerned QT interval?
Underlying heart problems, hypokalemia, hypomagnesemia. On other QT prolonging medications. Family or personal hx of prolonged QT interval, heart failure.
Is ondansetron use associated with increased risk of birth defects?
Some studies show increased risk (cleft palate, heart defect) others show no increased risk. The absolute risk to any fetus is low. Should counsel each woman on available data, especially before 10wks
Is methylprednisolone (for treatment of nausea/vomiting) use associated with increased risk of birth defects?
Association with increased risk of oral clefts with first trimester use (1-2 cases/1000 treated women)
What should be considered in patients with persistent hyperemesis gravidarum who are unresponsive to standard therapy?
Gastric ulcer. Consider testing for Helicobacter pylori infection.
What type of feedings are first line if woman with hyperemesis gravidarum is not responsive to medical therapy?
Enteral tube feeding (nasogastric or nasoduodenal)
What is the complication rate with PICC lines placed for women with hyperemesis gravidarum? What complications?
About 50%. Line infection, cellulitis, mechanical line failure, pain, thromboemolism, bacteremia, sepsis
