Further guidance on the management of nauseas and vomiting in pregnancy can be accessed from the Royal College of Obstetricians and Gynaecologists or NICE CKS. The UK teratology information service website Best Use of Medicines in Pregnancy (BUMPS) is also useful.

Women with mild to moderate nausea and vomiting in pregnancy (PUQE score 3-12 (see below) and no dehydration or ketonuria) should be managed in primary care.

• Reassure – 90% resolve by 16 weeks, nausea and vomiting are not usually associated with a poor pregnancy outcome
• Rest – fatigue exacerbates symptoms, support from family and friends with household chores and childcare can be helpful
• Diet – drinking little and often, small meals high in carbohydrate and low fat, avoid triggering foods/smells
• Acupressure at wrist (P6) – some randomised controlled trials (RCT) and systematic reviews have suggested a beneficial effect
• Ginger – was superior to placebo in some studies, and may be effective

Do not use diazepam, pyridoxine, herbal treatments, homeopathy, hypnotherapy, hypnosis, or psychotherapy. For further information on the formulary position on the use of herbal treatments and homeopathy, click here.

Where rest and dietary advice have been unsuccessful, early use of oral anti-emetics is recommended; these may reduce the risk of developing hyperemesis gravidarum.

1st line

Promethazine hydrochloride

• Initially 25mg at night; can be increased to 25mg morning and evening

See 3.4.1 antihistamines

OR

Cyclizine

• 50mg up to three times daily

See 4.6 Drugs used in nausea and vertigo

Note: these may cause sedation and other antimuscarinic side effects.

Review after 24 hours and if response is good, continue treatment and reassess weekly thereafter. It may be possible to stop anti-emetics at 12-16 weeks, using clinical judgement.

Consider combinations of different drugs in women who do not respond to a single anti-emetic.

If 1^st line anti-emetics are not effective and the woman is not dehydrated or ketonuric, consider 2^nd line anti-emetics.

2nd line

Metoclopramide

• 5-10mg three times a day for a maximum of 5 days (not for patients under 20 years old)

OR

Prochlorperazine

• Oral tablets: 5-10mg up to three times a day
• Buccal tablets: 3-6mg twice daily

See 4.6 Drugs used in nausea and vertigo

Note: there is an increased risk of extrapyramidal side effects and oculogyric crises with both metoclopramide and prochlorperazine.

Review patients regularly.

Consider combinations of different drugs in women who do not respond to a single anti-emetic.

3rd line

Ondansetron (unlicensed indication) (preferably not in the first trimester)

• 4mg up to twice daily

See 4.6 Drugs used in nausea and vertigo

Notes:
Patients must be counselled regarding the benefits of ondansetron together with the small increase in risk of orofacial cleft following use in the first 12 weeks of pregnancy. The background risk for orofacial cleft is 11 per 10,000 pregnancies. The risk of orofacial cleft is 14 per 10,000 pregnancies following ondansetron use in the first trimester. This equates to an additional 3 cases of orofacial cleft per 10,000 pregnancies exposed to ondansetron.

For further information, refer to:

• the UK Teratology Information Service (UKTIS) response statement and monograph for ondansetron
• MHRA Drug Safety Update (January 2020): ondansetron: small increased risk of oral clefts following use in the first 12 weeks of pregnancy
• for patient information, refer to BUMPS

The Royal College of Obstetricians and Gynaecologists recommends the use of ondansetron should be limited to patients who are not adequately managed on the first- and second-line anti-emetics above, and preferably used after the first trimester of pregnancy. For further information, refer to RCOG guidance, and BUMPS.

The SPCs for ondansetron products will be updated to indicate that ondansetron should not be used during the first trimester of pregnancy. For advice on prescribing ondansetron, see MHRA Drug Safety Update (January 2020): ondansetron small increased risk of oral clefts following use in the first 12 weeks of pregnancy

Ondansetron must not be used in patients with any history suggestive of prolonged QT; co-administration with other medicines which prolong the QT interval should be avoided.

Review patients regularly.

Consider combinations of different drugs in women who do not respond to a single anti-emetic.

If oral anti-emetics are unsuccessful, or cannot be kept down, consider referral.

Secondary care management usually takes the form of outpatient visits, rather than inpatient care, and may include daily saline infusions for dehydration.

Pregnancy Unique Quantification of Emesis (PUQE) index

Severity of symptoms can be quantified using the Pregnancy Unique Quantification of Emesis (PUQE) index:

Motherisk PUQE-24 Scoring system

PUQE-24 score: Mild ≤ 6, Moderate = 7-12, Severe = 13-15