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Vomiting in early pregnancy
Last reviewed: 05.07.2025

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Nausea and vomiting are the most common symptoms during early pregnancy; their occurrence is related to the rapid increase in estrogen levels. Although vomiting is most common in the morning (morning sickness), nausea and vomiting can occur at any time of day. These symptoms are most common and most severe during the first trimester of pregnancy.
Hyperemesis gravidarum is persistent vomiting associated with pregnancy that results in significant dehydration, electrolyte imbalances, or ketosis. Occasionally, prenatal iron supplementation is the cause of nausea. Rarely, severe, hyperemesis gravidarum results from a hydatidiform mole. Vomiting may also result from nonobstetric disorders.
Epidemiology
Nausea affects approximately 70% of pregnant women and vomiting affects approximately 60% of pregnant women. The true incidence of hyperemesis gravidarum is unknown. Documented rates range from 3 per 1,000 to 20 per 1,000 pregnancies. However, most authors report an incidence of 1 per 200. [ 1 ]
Causes early vomiting
The causes of nausea and vomiting during pregnancy are unknown. One theory, that they are caused by increased levels of human chorionic gonadotropin, is consistent with the natural history of the disease, its severity in pregnancies affected by a hydatidiform mole, and the good prognosis.
The cause of hyperemesis gravidarum is also unclear. Again, endocrine and psychological factors are suspected, but the evidence is inconclusive. Female sex of the fetus has been found to be a clinical indicator of hyperemesis gravidarum. One prospective study found that Helicobacter pylori infection was more common in pregnant women with hyperemesis gravidarum than in pregnant women without hyperemesis gravidarum (number of women with positive serum Helicobacter pylori immunoglobulin G concentrations: 95/105 [91%] with hyperemesis gravidarum v 60/129 [47%] without hyperemesis gravidarum). However, it was unclear whether this association was causal.
Diagnostics early vomiting
Vomiting is probably not due to pregnancy if it begins after the first trimester. Vomiting is likely due to pregnancy if it lasts for several days to several weeks, and there is no abdominal pain or other obvious cause for vomiting. If hyperemesis gravidarum is suspected, urine ketones should be measured; if symptoms are particularly severe and persistent, serum electrolytes should be measured. A normal intrauterine pregnancy should be confirmed to exclude a hydatidiform mole. Other tests are done based on clinically suspected nonobstetric disorders.
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Treatment early vomiting
In case of vomiting of pregnant women, fractional drinking and nutrition are prescribed (5-6 meals a day in small fractional portions) using small amounts of soft food products (for example, crackers, soft drinks, diet for children: bananas, rice, applesauce, dry toast). Food can help reduce the intensity of vomiting. If dehydration occurs (due to uncontrollable vomiting of pregnant women), isotonic sodium chloride solution is prescribed intravenously, and electrolyte imbalances are necessarily corrected.
The antiemetics doxylamine (10 mg orally at bedtime), metoclopramide (10 mg orally or intravenously every 8 hours as needed), ondansetron (8 mg orally or intramuscularly every 12 hours as needed), promethazine (12.5-25.0 mg orally, intramuscularly, or rectally every 6 hours as needed), and pyridoxine (vitamin B6; 10-25 mg orally 3 times a day as needed) are prescribed. These drugs are used extensively to reduce nausea and vomiting in the first trimester of pregnancy with no evidence of adverse effects on the fetus and can be used successfully throughout pregnancy. Ginger, acupuncture, and hypnosis are widely prescribed, and prenatal vitamins and children's chewable vitamins with folic acid may also help.
For nausea and vomiting in early pregnancy:
Ginger may reduce nausea and vomiting during pregnancy compared with placebo, although studies used different ginger preparations and reported different outcome rates.
Pyridoxine may be more effective than placebo in reducing nausea, but we don't know about vomiting and the evidence was weak.
Pyridoxine may be as effective as ginger in reducing nausea and vomiting, although evidence is limited.
Acupressure may be more effective than sham acupressure at reducing nausea and vomiting. However, the evidence was weak, and interventions and outcomes varied across studies.
It is not known whether acupressure is more effective than pyridoxine in reducing nausea or vomiting, as we did not find enough evidence.
It is not known whether acupuncture is more effective than sham acupuncture in reducing nausea and vomiting.
It is not known whether prochlorperazine, promethazine, or metoclopramide reduce nausea or vomiting compared with placebo.
In case of hyperemesis gravidarum:
It is not known whether acupressure, acupuncture, corticosteroids, ginger , metoclopramide, or ondansetron are effective in the treatment of hyperemesis gravidarum.
Hydrocortisone may be more effective than metoclopramide in reducing episodes of vomiting and reducing intensive care unit readmissions in women with hyperemesis gravidarum.
Forecast
One systematic review (search date: 1988) found that nausea and vomiting was associated with a reduced risk of miscarriage (six studies, 14 564 women; OR 0.36, 95% CI 0.32 to 0.42), but no association with perinatal mortality.
Some believe that hyperemesis gravidarum causes nutrient partitioning in favor of the fetus, which may explain the association with improved fetal outcome. Nausea, vomiting, and hyperemesis gravidarum typically improve over the course of pregnancy, but in one cross-sectional observational study, 13% of women reported that nausea and vomiting persisted beyond 20 weeks of gestation. Although death from nausea and vomiting during pregnancy is rare, conditions such as Wernicke's encephalopathy, splenic rupture, esophageal rupture, pneumothorax, and acute tubular necrosis have been reported.