Management of First Trimester Nausea and Vomiting

Assessment and Diagnosis

• The severity of nausea and vomiting during pregnancy can be quantified using the Motherisk Pregnancy-Unique Quantification of Emesis (PUQE) score, which evaluates duration of nausea, frequency of vomiting, and frequency of retching over a 12-hour period, with scores ranging from mild (≤6) to severe (≥13) 1

First-Line Non-Pharmacological Interventions

• Diet modifications, such as small, frequent, bland meals, BRAT diet (bananas, rice, applesauce, toast), high-protein, low-fat meals, and avoidance of spicy, fatty, acidic, and fried foods, are recommended for first trimester nausea and vomiting 1, 2, 3
• Lifestyle modifications, including identification and avoidance of specific triggers, separation of solid and liquid intake, and avoidance of an empty stomach, can help alleviate symptoms 1, 2, 3

First-Line Pharmacological Interventions

• Ginger 250 mg capsules four times daily is recommended by the American College of Obstetricians and Gynecologists (ACOG) as a safe and effective treatment for mild symptoms 1, 2, 3
• Vitamin B6 (pyridoxine) is shown to significantly improve symptoms according to PUQE and Rhode's scores, with a recommended dose of 10-25 mg every 8 hours (up to 40-60 mg/day) 1, 2

Second-Line Pharmacological Interventions

• Metoclopramide, 5-10 mg orally every 6-8 hours, has been shown to be safe and effective, with a meta-analysis of six cohort studies (33,000 first-trimester exposures) demonstrating no significant increase in risk of major congenital defects (odds ratio 1.14, 99% CI 0.93-1.38) 4, 5
• Ondansetron can be used when other treatments fail, but carries a small risk of cleft palate (0.03% absolute increase) and ventricular septal defects (0.3% absolute increase) 4, 5

Third-Line Interventions for Severe Cases (Hyperemesis Gravidarum)

• Intravenous hydration and correction of electrolyte abnormalities are recommended for severe cases, along with thiamine supplementation to prevent Wernicke's encephalopathy 2, 6
• Corticosteroids, such as methylprednisolone or prednisolone, may be considered for severe, refractory cases, but should be avoided before 10 weeks gestation due to increased risk of oral clefts 4, 5, 6

Important Clinical Considerations

• Early intervention is crucial to prevent progression to hyperemesis gravidarum, which affects 0.3-2% of pregnancies and is characterized by intractable vomiting, dehydration, weight loss >5% of prepregnancy weight, and electrolyte imbalances 1, 2, 6
• Most NVP begins at 4-6 weeks, peaks at 8-12 weeks, and subsides by week 20, and a multidisciplinary approach involving obstetrics and gastroenterology may be beneficial for patients with moderate to severe symptoms 1, 2

Nausea and Vomiting in Pregnancy Management

Medication Considerations

• Metoclopramide can be used for nausea in adolescents 12-17 years, though unlikely to prevent vomiting when given orally 7
• Sodium valproate should be avoided due to its known teratogenic effects 7
• Topiramate and candesartan are associated with fetal adverse effects and should be avoided 7
• Paracetamol is preferred for breastfeeding, though ibuprofen is also considered safe 7
• Metoclopramide can be used for nausea during breastfeeding 7

Management of Nausea and Vomiting in Pregnancy

Pharmacological Treatment

• The American College of Obstetricians and Gynecologists (ACOG) recommends using ondansetron on a case-by-case basis in patients with persistent symptoms before 10 weeks of pregnancy, balancing the very small increase in absolute risk of orofacial clefting against the risks of poorly managed hyperemesis gravidarum 8
• Thiamine supplementation 100 mg daily for a minimum of 7 days, followed by a maintenance dosage of 50 mg daily, is recommended to prevent Wernicke encephalopathy and refeeding syndrome in severe cases requiring hospitalization 8
• Methylprednisolone 16 mg IV every 8 hours for up to 3 days, followed by tapering over 2 weeks, can be given as a last resort in severe hyperemesis gravidarum and reduces rehospitalization rates 8

Medications to Avoid

• Methotrexate should never be used at any stage of pregnancy due to severe teratogenic effects 9
• Older-generation alkylating agents, such as procarbazine and busulfan, thalidomide, lenalidomide, pomalidomide, and tretinoin, should be avoided during pregnancy 9

Treatment Approach

• Preventing nausea and vomiting is much easier than treating it once established; therefore, consider around-the-clock administration of antiemetics rather than PRN dosing for moderate to severe cases 10
• If extrapyramidal effects occur with metoclopramide, promptly discontinue the medication 8

Treatment of Severe Morning Sickness in First Trimester

Medication Use in Pregnancy

• The American College of Obstetricians and Gynecologists recommends doxylamine-pyridoxine combination (Diclectin) as the preferred first-line pharmacologic therapy for pregnancy nausea 11
• Methylprednisolone 16 mg IV every 8 hours for up to 3 days, then taper over 2 weeks, reduces rehospitalization rates in severe refractory cases, according to Annals of Oncology 11

Corticosteroid Use

• Corticosteroids should be avoided before 10 weeks gestation due to small risk of oral clefts, and methylprednisolone or prednisolone should be used instead of other steroids 11

Steroid Use in Severe Refractory Hyperemesis Gravidarum

Corticosteroid Selection

• In pregnant patients with severe refractory hyperemesis gravidarum who require corticosteroid therapy, methylprednisolone or prednisolone are the preferred agents, and other corticosteroids should be avoided because they are not considered safe in pregnancy 12