Nausea and vomiting in pregnancy (colloquially known as "morning sickness") are common complaints. The American College of Obstetricians and Gynecologists practice guidelines state that 70% to 85% of pregnant women experience nausea and vomiting at some point during the pregnancy (ACOG, 2004).
It is most common during the 1st trimester of pregnancy and usually disappears by the 14th week of pregnancy. It is important to determine the etiology of the patient's vomiting, taking into account the frequency, severity, and onset (e.g. presentations of vomiting later along in the pregnancy) and associated symptoms to create a differential diagnosis.
N/V in pregnancy can have a significant impact on jobs, activities, family relationships, and moods.
Hyperemesis gravidarum is nausea and vomiting severe enough to cause physiological and biochemical effects, including significant dehydration, often with electrolyte abnormalities, ketosis, and weight loss. It usually occurs during the first trimester of ~1% of all pregnancies and then decreases, but is present throughout pregnancy in a few women.
A 22-year old pregnant women comes to your family practice complaining of nausea and vomiting for the past week with increasing severity. She is 6 weeks pregnant and this is her first pregnancy.
Causes of nausea and vomiting in pregnancy include:
Risk factors include:
The pathophysiology remains unclear, however, the cause of nausea and vomiting in pregnancy is thought to be related to the high levels of beta-hCG and estrogen, as well as other hormonal, immunologic, and psychological contributors.
It is important to take a complete history, as morning sickness or hyperemesis are diagnoses of exclusion.
Ask about intake patterns to determine if any offending foods may be identified.
History of present illness:
Important associated symptoms include:
Review of systems should seek symptoms of nonobstetric causes of nausea and vomiting, including
Past medical/surgical history:
Physical exam findings that may be found, according to various causes of vomiting in pregnancy, include:
head and neck
Important investigations for serious vomiting include:
Given other items on the differential, it is reasonable to consider:
A fetal doppler should be used to ascertain fetal viability. If it is not able to be located, ultrasound surveillance is warranted to rule out hyadifirom mole.
It is important to consider and exclude other causes of nausea and vomiting, including:
It is important to also treat heartburn, depression, and anxiety.
Nausea and vomiting in pregnancy is generally mild and self-limiting.
According to one study, mean gestational age of onset approximately 6 weeks and with peak severity at weeks 11 to 13. Almost 50% of cases resolve by week 14 gestation, and 90% by week 22 (Lacroix, Ealson, and Melzack, 2000).
A prospective study of 575 women having live singleton births and 75 having spontaneous abortions found a decreased risk for spontaneous abortions in women having nausea during that pregnancy (3)
Maternal consequences include:
Fetal consequences are rare, but include IUGR.
American College of Obstetricians and Gynecologists (ACOG). Nausea and vomiting of pregnancy. Washington (DC): American College of Obstetricians and Gynecologists (ACOG); 2004 Apr. 13 p. (ACOG practice bulletin; no. 52).
authors: Sophie Maurice
reviewers: David LaPierre