N/V is common and considered to be a normal physiologic change in pregnancy, called “nausea and vomiting of pregnancy - NVP” or “morning sickness”.
The severe end of the spectrum of NVP is called 'hyperemesis gravidarum'. There is no clear-cut line between these two clinical conditions, but the most common criteria are as follows.
Weight loss exceeding 5 percent of prepregnancy weight
Ketonuria
Diagnosis
Clinical by the exclusion of other diseases
Clue based on early pregnancy onset that gradually resolves within GA 16 wks.
Evaluation
Weight
Orthostatic blood pressure and heart rate
Fetal viability (fetal cardiac activity)
Obstetric U/S for fetal number or presence of a molar pregnancy
Lab
E’lyte
Urine ketones and specific gravity
Treatment
Mild (no/not frequent vomiting)
Dietary changes and trigger avoidance
Ginger extract/tea, pyridoxine (vitamin B6)
Add doxylamine if symptoms not improved
Moderate (with frequent vomiting)
Same as above + metoclopramide
Add ondansetron if symptoms not improved
Add glucocorticoid if symptoms not improved
Severe/Hyperemesis gravidarum
IV rehydration with supplement e’lyte and thiamine (vitamin B1)