Evidence-Based Approaches to Managing Nausea and Vomiting in Early Pregnancy

Tekoa L. King, CNM, MPH; Patricia Aikins Murphy, CNM, DrPH

Disclosures

J Midwifery Womens Health. 2009;54(6):430-444. 

In This Article

Clinical Implications

A stepwise and systematic approach to the clinical management of women with NVP using treatments that have been shown to be both safe and efficacious will best help affected women. Using a systematic approach in combination with frequent clinic visits (every 4 days to weekly for women with severe symptoms) can also prevent escalating morbidity and save health care resources. That said, it is important to note that there are no standard treatment algorithms and to remember that many of medications used to treat NVP are not approved by the FDA specifically for this purpose. The clinical management algorithm currently recommended by both ACOG[92] and the Society of Obstetricians and Gynaecologists of Canada[110] is based on the work of the Motherisk Team at The Hospital for Sick Children in Toronto, Ontario, Canada. The algorithm presented in Figure 5 is adapted from recommendations from Levichek et al.,[111] ACOG,[92] the Society of Obstetricians and Gynaecologists of Canada,[110] and formatted for use by clinicians in the United States.

Figure 5.

Protocol for assessing and treating women with nausea and vomiting in pregnancy. Adapted from the American College of Obstetricians and Gynecologists,[92] Arsenault et al.,[110] and Levichek et al.[111]

Most women with a PUQE Index score of ≤6 (mild) are not retching or vomiting frequently and, in general, they are most likely to manage their NVP with lifestyle modifications and nonpharmacologic treatments. Ginger can be considered as a monotherapy or as an adjunct therapy to other treatments. Acupressure and acupuncture may also be of benefit for some women.

When the PUQE Index score is ≥7 or when a woman desires medication to help decrease nausea, start with vitamin B6 25 mg 3 times per day and half of a tablet of doxylamine (Unisom tablets) taken 3 times per day. The safety profile of both of these agents is very good.[85,112,113] If a woman needs relief from occasional retching and/or vomiting, phenothiazines will reliably stop vomiting episodes, and most professional association guidelines recommend adding phenothiazines first for women who need relief from vomiting.[92,110,114] Phenothiazines taken orally or used as a rectal suppository can be helpful for breakthrough vomiting, but because they are associated with significant sedation, women may not feel comfortable taking them. Therefore, metoclopramide (Reglan) is recommended if a medication is needed for regular daily use.

Severe nausea or frequent retching/vomiting can quickly result in dehydration. When a woman has signs of dehydration, management is intensified and frequent follow-up needs to be instituted. Treatment of dehydration can involve both IV fluid replacement and antiemetics that suppress vomiting. Metoclopramide can be used intravenously to interrupt an episode of vomiting, and it can be then prescribed orally for use at home after a hospital visit. Weekly visits to record the woman's weight and assess her urine for signs of dehydration are important, because a woman may need frequent changes in her treatment regimen before an effective and individualized treatment plan can be established.

Ondansetron (Zofran) has a unique role in the treatment of NVP. It has a reputation for being the most effective antiemetic in use, but the single study published to date that compared ondansetron to other antiemetics in pregnant women did not find it to be more effective than phenothiazines.[115] It is being used more frequently, and because it is very expensive, many insurance companies will not approve its use until a woman has failed more conventional therapies. More research needs to be performed to better determine if the perceived effectiveness of ondansetron is real.

When nausea and retching/vomiting results in dehydration despite a trial of an antiemetic that reliably stops vomiting (e.g., metoclopramide, phenothiazines, or ondansetron), medical consultation and referral is necessary. If the NVP is severe enough to entertain a diagnosis of HG, inpatient management may be required. HG is diagnosed after other etiologies of severe nausea and vomiting, such as molar pregnancy or multiple gestation, are ruled out. Regardless of the etiology, treatment for the nausea and vomiting will be instituted. Inpatient admission can involve several therapeutic regimens that include intravenous fluids, antiemetics, vitamin B1 replacement to prevent Wernicke encephalopathy,[116] corticosteroids, and nasogastric feeding or parenteral nutrition.[117] Home health services can be extremely helpful in outpatient care after a hospitalization for HG.[118] Although the management of HG is not the focus of this review, the interested reader can find more detailed information about inpatient management in several recent reviews.[32,92,117]

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