Nausea & Vomiting in Pregnancy

Question 1

What is the PREVALENCE of NVP?

Answer 1

AKA morning sickness, but can occur at anytime of the day

v. common, occurs in ~50-80% pregnancies

implications:
- reduced activity at home & work
- days off from work
- frustration, stress, depression
- utilization of health care services
- decreased QOL

Question 2

What is the ETIOLOGY of NVP?

Answer 2

UNKNOWN, theories include:

• Hormonal changes
  – ELEVATED human chorionic gonadotropin (hCG) peak in 1st trimester. Levels found to be higher in women w/ hyperemesis
• ELEVATED estrogen & progesterone may also contribute
• Changes in GI motility
  – delayed gastric emptying, decreased esophageal sphincter tone
• H. pylori infection
  – association noted in epidemiological studies

Question 3

What are the SYMPTOMS & COURSE of NVP?

Answer 3

• Nausea, vomiting, retching
• Can occur any time of day, not just morning
• Vomitus – nonbilious & NO BLOOD

Course:
- begins by 6 weeks
- most severe b/t 7-12 weeks
- lessens by 12-20 weeks, regardless of tx
- throughout pregnancy for 10% of women
- onset after 9 weeks rare

Question 4

What are the COMMON CAUSES of NVP?

Answer 4

Hyperemesis gravidarum
- incidence: up to 2% of pregnancy women
- persistent, intractable vomiting
- dehydration, >5% weight loss, electrolyte disturbances, ketosis
- may require hospitalization
(not able to keep anything down, not even water)

Other causes:
- ex: appendicitis, hepatitis, pancreatitis, biliary tract disease, pyelonephritis, diabetic ketoacidosis, migraine, infections
- diagnosis through exclusion
- can rule out w/ additional bloodwork, evaluation of sx’s

Question 5

What are the RISK FACTORS of NVP?

Answer 5

• multiple pregnancy (ex: twins)
• NVP in previous pregnancy
• fam history of NVP
• molar pregnancy
• history of GI problems (ex: heartburn, acid reflux, Crohn’s)
• history of migraines
• history of motion sickness

Question 6

What are the COMPLICATIONS (outcomes?) of NVP?

Answer 6

• not associated w/ AE’s on fetus
• lower rates of miscarriage
• likely to recur in future pregnancies
• Hyperemesis gravidarum
  – NO adverse outcome if mother’s weight “catches up” later in pregancy
  – severe cases w/ poor weight gain
  — low birth weight, prematurity
  – 1% of women require hospitalization due to severity of NVP

Question 7

What are the NON-PHARM TX OPTIONS of NVP?

Answer 7

• Ginger –> enhances GI transport, possible CNS antiemetic effects, causes less drowsiness than 1st gen antihistamines
• Acupuncture/acupressure –> stimulation of P6 point 3 finger-widths above wrist on inside forearm
• Pyridoxine (vitamin B6) –> safe, minimal SE’s, OTC, improves mild/mod nausea *BUT not vomiting
• Doxylamine/pyridoxine –> 1st gen antihistamine + vitamin B6
  – Diclectin typ. 1st prescribed (SR)

Question 8

What are the PHARMACOLOGIC TX OPTIONS of NVP?

Answer 8

Recent concerns about lack of efficacy, bias in studies

AE: sedation, fatigue

Safety - not been found to increase the risk of major malformations in >33 million pregnant women worldwide

Other antihistamines - dimenhydrinate, diphenhydramine

Dopamine antagonists - metoclopramide, chlorpromazine, prochlorperazine (reserved for more severe cases b/c of extrapyramidal SE’s)

May combine above 2 for hyperemesis gravidarum

5HT-3 antagonist - ondansetron
- serotonin antagonist
- do not use in pregnancy
- increased risk birth defects (heart) in 1st trimester
- can cause QT prolongation

Corticosteroids
- high doses may be useful in severe cases NVP
- use only if other options ineffective

Question 9

When is referral to physician necessary?

Answer 9

• unable to keep food/water down >24 hours
• sign. weight loss
• signs of dehydration
  – INCREASE thirst, DECREASE urine output, dry mouth, weakness
• signs of infection
  – other sx’s inconsistent w/ NVP
  — neurological
  — hematemesis
  — abdominal pain
• ONSET of NVP after 10 weeks or return of sx’s