Nausea and Vomiting During Early Pregnancy
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Nausea and vomiting affect up to 80% of pregnant women. Symptoms are most common and most severe during the 1st trimester. Although common usage refers to morning sickness, nausea, vomiting, or both typically may occur at any point during the day. Symptoms vary from mild to severe (hyperemesis gravidarum).
Hyperemesis gravidarum is persistent, severe pregnancy-induced vomiting that causes significant dehydration, often with electrolyte abnormalities, ketosis, and weight loss (see Abnormalities of Pregnancy: Hyperemesis Gravidarum).
Pathophysiology
The pathophysiology of nausea and vomiting during early pregnancy is unknown, although metabolic, endocrine, GI, and psychologic factors probably all play a role. Estrogen may contribute because estrogen levels are elevated in patients with hyperemesis gravidarum.
Etiology
The most common causes of uncomplicated nausea and vomiting during early pregnancy (see Table 4: Approach to the Pregnant Woman and Prenatal Care: Some Causes of Nausea and Vomiting During Early PregnancyTables) are
*
Morning sickness (most common)
*
Hyperemesis gravidarum
*
Gastroenteritis
Occasionally, prenatal vitamin preparations with iron cause nausea. Rarely, severe, persistent vomiting results from hydatidiform mole.
Vomiting can also result from many nonobstetric disorders. Common causes of acute abdomen (eg, appendicitis, cholecystitis) may occur during pregnancy and may be accompanied by vomiting, but the chief complaint is typically pain rather than vomiting. Similarly, some CNS disorders (eg, migraine, CNS hemorrhage, increased intracranial pressure) may be accompanied by vomiting, but headache or other neurologic symptoms are typically the chief complaint.
Table 4
Some Causes of Nausea and Vomiting During Early Pregnancy
Cause
Suggestive Findings
Diagnostic Approach
Obstetric
Morning sickness (uncomplicated nausea and vomiting)
Mild, intermittent symptoms at varying times throughout the day, primarily during the 1st trimester
Normal vital signs and physical examination
Diagnosis of exclusion
Hyperemesis gravidarum
Frequent, persistent nausea and vomiting with inability to maintain adequate oral intake of fluids, food, or both
Usually, signs of dehydration (eg, tachycardia, dry mouth, thirst), weight loss
Urine ketones, serum electrolytes, Mg, BUN, creatinine
If the condition persists, possibly liver function tests, pelvic ultrasonography
Hydatidiform mole
Larger-than-expected uterine size, absent fetal heart sounds and movement
Sometimes elevated BP, vaginal bleeding, grapelike tissue from cervix
BP measurement, quantitative hCG, pelvic ultrasonography, biopsy
Nonobstetric
Gastroenteritis
Acute, not chronic; usually accompanied by diarrhea
Normal (benign) abdomen (soft, nontender, not distended)
Clinical evaluation
Bowel obstruction
Acute, usually in patients who have had abdominal surgery
Colicky pain, with obstipation and distended, tympanitic abdomen
May be caused by or occur in patients with appendicitis
Abdominal imaging with flat and upright x-rays, ultrasonography, and possibly CT (if x-ray and ultrasound results are equivocal)
UTI or pyelonephritis
Urinary frequency, urgency, or hesitancy, with or without flank pain and fever
Urinalysis and culture
hCG = Human chorionic gonadotropin.
Evaluation
Evaluation aims to exclude serious or life-threatening causes of nausea and vomiting. Morning sickness (uncomplicated nausea and vomiting) and hyperemesis gravidarum are diagnoses of exclusion.
History
History of present illness should particularly note the following:
*
Onset and duration of vomiting
*
Exacerbating and relieving factors
*
Type (eg, bloody, watery, bilious) and amount of emesis
*
Frequency (intermittent or persistent)
Important associated symptoms include diarrhea, constipation, and abdominal pain. If pain is present, the location, radiation, and severity should be queried. The examiner should also ask what social effects the symptoms have had on the patient and her family (eg, whether she is able to work or to care for her children).
Review of systems should seek symptoms of nonobstetric causes of nausea and vomiting, including fever or chills, particularly if accompanied by flank pain or voiding symptoms (UTI or pyelonephritis); and neurologic symptoms such as headache, weakness, focal deficits, and confusion (migraine or CNS hemorrhage).
Past medical history includes questions about morning sickness or hyperemesis in past pregnancies. Past surgical history should include questions about any prior abdominal surgery, which would predispose a patient to mechanical bowel obstruction.
Drugs taken by the patient are reviewed for drugs that could contribute (eg, iron-containing compounds, hormonal therapy) and for safety during pregnancy.
Physical examination
Examination begins with review of vital signs for fever, tachycardia, and abnormal BP (too low or too high).
A general assessment is done to look for signs of toxicity (eg, lethargy, confusion, agitation). Complete physical examination, including pelvic examination, is done to check for findings suggesting serious or potentially life-threatening causes of nausea and vomiting (see Table 5: Approach to the Pregnant Woman and Prenatal Care: Relevant Physical Examination Findings in a Pregnant Patient With VomitingTables).
Table 5
Relevant Physical Examination Findings in a Pregnant Patient With Vomiting
System
Findings
General
Lethargy, agitation
HEENT
Dry mucosa, icteric sclera
Neck
Stiffness to passive flexion (meningismus)
GI
Distention with tympany
Absent or high-pitched tinkling bowel sounds
Focal tenderness
Peritoneal signs (guarding, rigidity, rebound)
GU
Flank tenderness to percussion
Uterus too large for dates
Absent fetal heart sounds
Grapelike tissue from cervix
Neurologic
Confusion, photophobia, focal weakness, nystagmus
HEENT = Head, eyes, ears, nose, and throat.
Red flags
The following findings are of particular concern:
*
Abdominal pain
*
Signs of dehydration (eg, orthostatic hypotension, tachycardia)
*
Fever
*
Bloody or bilious emesis
*
No fetal motion or heart sounds
*
Abnormal neurologic examination
*
Persistent or worsening symptoms
Interpretation of findings
Distinguishing pregnancy-related vomiting from vomiting due to other causes is important. Clinical manifestations help (see Table 4: Approach to the Pregnant Woman and Prenatal Care: Some Causes of Nausea and Vomiting During Early PregnancyTables).
Vomiting is less likely to be due to pregnancy if it begins after the 1st trimester or is accompanied by abdominal pain, diarrhea, or both. Abdominal tenderness may suggest acute abdomen. Meningismus, neurologic abnormalities, or both suggest a neurologic cause.
Vomiting is more likely to be due to pregnancy if it begins during the 1st trimester, it lasts or recurs over several days to weeks, abdominal pain is absent, and there are no symptoms or signs involving other organ systems.
If vomiting appears to be pregnancy-related and is severe (ie, frequent, prolonged, accompanied by dehydration), hyperemesis gravidarum and hydatidiform mole should be considered.
Testing
Patients with significant vomiting, signs of dehydration, or both usually require testing. If hyperemesis gravidarum is suspected, urine ketones are measured; if symptoms are particularly severe or persistent, serum electrolytes are measured. If fetal heart sounds are not clearly audible or detected by fetal Doppler, pelvic ultrasonography should be done to rule out hydatidiform mole. Other tests are done based on clinically suspected nonobstetric disorders (see Table 4: Approach to the Pregnant Woman and Prenatal Care: Some Causes of Nausea and Vomiting During Early PregnancyTables).
Treatment
Pregnancy-induced vomiting may be relieved by drinking or eating frequently (5 or 6 small meals/day), but only bland foods (eg, crackers, soft drinks, BRAT diet [bananas, rice, applesauce, dry toast]) should be eaten. Eating before rising may help. If dehydration (eg, due to hyperemesis gravidarum) is suspected, 1 to 2 L of normal saline or Ringer's lactate is given IV, and any identified electrolyte abnormalities are corrected.
Certain drugs (see Table 6: Approach to the Pregnant Woman and Prenatal Care: Suggested Drugs for Nausea and Vomiting During Early PregnancyTables) can be used to relieve nausea and vomiting during the 1st trimester without evidence of adverse effects on the fetus.
Table 6
Suggested Drugs for Nausea and Vomiting During Early Pregnancy
Drug
Dose
Vitamin B6 (pyridoxine)
25 mg po tid
Doxylamine
25 mg po at bedtime
Promethazine
12.5?25 mg po, IM, or rectally q 6 h as needed
Metoclopramide
5?10 mg q 8 h po or IM
Ondansetron
8 mg po or IM q 12 h as needed
Vitamin B6 is used as monotherapy; other drugs are added if symptoms are not relieved.
Ginger (eg, ginger capsules 250 mg po tid or qid, ginger lollipops), acupuncture, motion sickness bands, and hypnosis may help, as may switching from prenatal vitamins to a children's chewable vitamin with folate.
Key Points
*
Vomiting during pregnancy is usually self-limited and responds to dietary modification.
*
Hyperemesis gravidarum is less common but is severe, leading to dehydration, ketosis, and weight loss.
*
Nonobstetric causes should be considered.
http://www.merck.com/mmpe/print/sec18/ch259/ch259d.html
-
-
Nausea and vomiting affect up to 80% of pregnant women. Symptoms are most common and most severe during the 1st trimester. Although common usage refers to morning sickness, nausea, vomiting, or both typically may occur at any point during the day. Symptoms vary from mild to severe (hyperemesis gravidarum).
Hyperemesis gravidarum is persistent, severe pregnancy-induced vomiting that causes significant dehydration, often with electrolyte abnormalities, ketosis, and weight loss (see Abnormalities of Pregnancy: Hyperemesis Gravidarum).
Pathophysiology
The pathophysiology of nausea and vomiting during early pregnancy is unknown, although metabolic, endocrine, GI, and psychologic factors probably all play a role. Estrogen may contribute because estrogen levels are elevated in patients with hyperemesis gravidarum.
Etiology
The most common causes of uncomplicated nausea and vomiting during early pregnancy (see Table 4: Approach to the Pregnant Woman and Prenatal Care: Some Causes of Nausea and Vomiting During Early PregnancyTables) are
*
Morning sickness (most common)
*
Hyperemesis gravidarum
*
Gastroenteritis
Occasionally, prenatal vitamin preparations with iron cause nausea. Rarely, severe, persistent vomiting results from hydatidiform mole.
Vomiting can also result from many nonobstetric disorders. Common causes of acute abdomen (eg, appendicitis, cholecystitis) may occur during pregnancy and may be accompanied by vomiting, but the chief complaint is typically pain rather than vomiting. Similarly, some CNS disorders (eg, migraine, CNS hemorrhage, increased intracranial pressure) may be accompanied by vomiting, but headache or other neurologic symptoms are typically the chief complaint.
Table 4
Some Causes of Nausea and Vomiting During Early Pregnancy
Cause
Suggestive Findings
Diagnostic Approach
Obstetric
Morning sickness (uncomplicated nausea and vomiting)
Mild, intermittent symptoms at varying times throughout the day, primarily during the 1st trimester
Normal vital signs and physical examination
Diagnosis of exclusion
Hyperemesis gravidarum
Frequent, persistent nausea and vomiting with inability to maintain adequate oral intake of fluids, food, or both
Usually, signs of dehydration (eg, tachycardia, dry mouth, thirst), weight loss
Urine ketones, serum electrolytes, Mg, BUN, creatinine
If the condition persists, possibly liver function tests, pelvic ultrasonography
Hydatidiform mole
Larger-than-expected uterine size, absent fetal heart sounds and movement
Sometimes elevated BP, vaginal bleeding, grapelike tissue from cervix
BP measurement, quantitative hCG, pelvic ultrasonography, biopsy
Nonobstetric
Gastroenteritis
Acute, not chronic; usually accompanied by diarrhea
Normal (benign) abdomen (soft, nontender, not distended)
Clinical evaluation
Bowel obstruction
Acute, usually in patients who have had abdominal surgery
Colicky pain, with obstipation and distended, tympanitic abdomen
May be caused by or occur in patients with appendicitis
Abdominal imaging with flat and upright x-rays, ultrasonography, and possibly CT (if x-ray and ultrasound results are equivocal)
UTI or pyelonephritis
Urinary frequency, urgency, or hesitancy, with or without flank pain and fever
Urinalysis and culture
hCG = Human chorionic gonadotropin.
Evaluation
Evaluation aims to exclude serious or life-threatening causes of nausea and vomiting. Morning sickness (uncomplicated nausea and vomiting) and hyperemesis gravidarum are diagnoses of exclusion.
History
History of present illness should particularly note the following:
*
Onset and duration of vomiting
*
Exacerbating and relieving factors
*
Type (eg, bloody, watery, bilious) and amount of emesis
*
Frequency (intermittent or persistent)
Important associated symptoms include diarrhea, constipation, and abdominal pain. If pain is present, the location, radiation, and severity should be queried. The examiner should also ask what social effects the symptoms have had on the patient and her family (eg, whether she is able to work or to care for her children).
Review of systems should seek symptoms of nonobstetric causes of nausea and vomiting, including fever or chills, particularly if accompanied by flank pain or voiding symptoms (UTI or pyelonephritis); and neurologic symptoms such as headache, weakness, focal deficits, and confusion (migraine or CNS hemorrhage).
Past medical history includes questions about morning sickness or hyperemesis in past pregnancies. Past surgical history should include questions about any prior abdominal surgery, which would predispose a patient to mechanical bowel obstruction.
Drugs taken by the patient are reviewed for drugs that could contribute (eg, iron-containing compounds, hormonal therapy) and for safety during pregnancy.
Physical examination
Examination begins with review of vital signs for fever, tachycardia, and abnormal BP (too low or too high).
A general assessment is done to look for signs of toxicity (eg, lethargy, confusion, agitation). Complete physical examination, including pelvic examination, is done to check for findings suggesting serious or potentially life-threatening causes of nausea and vomiting (see Table 5: Approach to the Pregnant Woman and Prenatal Care: Relevant Physical Examination Findings in a Pregnant Patient With VomitingTables).
Table 5
Relevant Physical Examination Findings in a Pregnant Patient With Vomiting
System
Findings
General
Lethargy, agitation
HEENT
Dry mucosa, icteric sclera
Neck
Stiffness to passive flexion (meningismus)
GI
Distention with tympany
Absent or high-pitched tinkling bowel sounds
Focal tenderness
Peritoneal signs (guarding, rigidity, rebound)
GU
Flank tenderness to percussion
Uterus too large for dates
Absent fetal heart sounds
Grapelike tissue from cervix
Neurologic
Confusion, photophobia, focal weakness, nystagmus
HEENT = Head, eyes, ears, nose, and throat.
Red flags
The following findings are of particular concern:
*
Abdominal pain
*
Signs of dehydration (eg, orthostatic hypotension, tachycardia)
*
Fever
*
Bloody or bilious emesis
*
No fetal motion or heart sounds
*
Abnormal neurologic examination
*
Persistent or worsening symptoms
Interpretation of findings
Distinguishing pregnancy-related vomiting from vomiting due to other causes is important. Clinical manifestations help (see Table 4: Approach to the Pregnant Woman and Prenatal Care: Some Causes of Nausea and Vomiting During Early PregnancyTables).
Vomiting is less likely to be due to pregnancy if it begins after the 1st trimester or is accompanied by abdominal pain, diarrhea, or both. Abdominal tenderness may suggest acute abdomen. Meningismus, neurologic abnormalities, or both suggest a neurologic cause.
Vomiting is more likely to be due to pregnancy if it begins during the 1st trimester, it lasts or recurs over several days to weeks, abdominal pain is absent, and there are no symptoms or signs involving other organ systems.
If vomiting appears to be pregnancy-related and is severe (ie, frequent, prolonged, accompanied by dehydration), hyperemesis gravidarum and hydatidiform mole should be considered.
Testing
Patients with significant vomiting, signs of dehydration, or both usually require testing. If hyperemesis gravidarum is suspected, urine ketones are measured; if symptoms are particularly severe or persistent, serum electrolytes are measured. If fetal heart sounds are not clearly audible or detected by fetal Doppler, pelvic ultrasonography should be done to rule out hydatidiform mole. Other tests are done based on clinically suspected nonobstetric disorders (see Table 4: Approach to the Pregnant Woman and Prenatal Care: Some Causes of Nausea and Vomiting During Early PregnancyTables).
Treatment
Pregnancy-induced vomiting may be relieved by drinking or eating frequently (5 or 6 small meals/day), but only bland foods (eg, crackers, soft drinks, BRAT diet [bananas, rice, applesauce, dry toast]) should be eaten. Eating before rising may help. If dehydration (eg, due to hyperemesis gravidarum) is suspected, 1 to 2 L of normal saline or Ringer's lactate is given IV, and any identified electrolyte abnormalities are corrected.
Certain drugs (see Table 6: Approach to the Pregnant Woman and Prenatal Care: Suggested Drugs for Nausea and Vomiting During Early PregnancyTables) can be used to relieve nausea and vomiting during the 1st trimester without evidence of adverse effects on the fetus.
Table 6
Suggested Drugs for Nausea and Vomiting During Early Pregnancy
Drug
Dose
Vitamin B6 (pyridoxine)
25 mg po tid
Doxylamine
25 mg po at bedtime
Promethazine
12.5?25 mg po, IM, or rectally q 6 h as needed
Metoclopramide
5?10 mg q 8 h po or IM
Ondansetron
8 mg po or IM q 12 h as needed
Vitamin B6 is used as monotherapy; other drugs are added if symptoms are not relieved.
Ginger (eg, ginger capsules 250 mg po tid or qid, ginger lollipops), acupuncture, motion sickness bands, and hypnosis may help, as may switching from prenatal vitamins to a children's chewable vitamin with folate.
Key Points
*
Vomiting during pregnancy is usually self-limited and responds to dietary modification.
*
Hyperemesis gravidarum is less common but is severe, leading to dehydration, ketosis, and weight loss.
*
Nonobstetric causes should be considered.
http://www.merck.com/mmpe/print/sec18/ch259/ch259d.html
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