Nausea and vomiting affect 50-90% of pregnancies (1). Beginning from before 9 weeks gestation it most commonly resolves between 10 and 16 weeks gestation (2). Although referred to as ‘morning sickness’ the nausea and vomiting in pregnancy may occur throughout the day.
Nausea and vomiting in pregnancy is thought to be associated with raised thyroxine levels and Human Chorionic Gonadotropin (HCG) or suppressed Thyroid Stimulating Hormone (TSH) levels. There is no good evidence to support psychological and behavioural theories (1). It is important that other causes of nausea and vomiting be ruled out. Idiopathic nausea and vomiting in pregnancy must be distinguished from nausea and vomiting in pregnancy of known causes such as hydatiform mole or multiple gestation.
The physical and emotional impact of nausea and vomiting in pregnancy often results in feelings of anxiety about the effect of the symptoms on the baby. Nausea and vomiting in pregnancy also impacts on a woman’s family relationships and ability to work. Around 47% of working women with nausea and vomiting in pregnancy feel their job efficiency is reduced (3). Around 35% lose work time and 25% lose time from housework. Nausea and vomiting in pregnancy has also been cited as a reason for elective termination of pregnancy (4). This is not surprising when you consider studies that have found nausea and vomiting in pregnancy experienced by pregnant women is comparable to that experienced by patients undergoing chemotherapy for cancer (5).
Management of mild nausea and vomiting
Women should be reassured that nausea and vomiting in pregnancy is normal, and in mild to moderate cases it is not associated with adverse outcomes. Nausea and vomiting in pregnancy is associated with a decreased risk of spontaneous abortion (1,6). There are dietary changes and alternative therapies that can help in the management of nausea and vomiting in pregnancy.
1) Dietary modifications:
- Small, dry, bland, frequent meals, avoiding fatty or spicy foods, should be encouraged
- Eating a small portion prior to getting out of bed in the morning may help alleviate symptoms
- B6 can be beneficial and is found in tuna, mackerel, bananas, avocado, raisins, sunflower seeds and hazelnuts. Vitamin supplements should be used with caution.
- Avoiding foods with strong odours can reduce symptoms
2) Alternative therapies:
- Ginger root has been shown to reduce the symptoms of nausea and vomiting in pregnancy (7)
- Acupuncture and acupressure has been shown to reduce nausea (eg. PSI bands) (8)
- Small amounts of fluid regularly between meals is ideal
1. Gadsby R, Barnie-Adshead AM, Jagger C. A prospective study of nausea and vomiting during pregnancy. Br J Gen Pract. 1993;43:245-8
2. Goodwin M. Hyperemesis gravidarum Clinical obstetrics and gynecology. 1998;41(3):597-605
3. O’Brien B, Naber S. Nausea and vomiting during pregnancy: effects on the quality of women’s lives. Birth 1992; 19:138-43
4. Mazzotta P, Magee LA, Koren G. Therapeutic abortions due to severe morning sickness: Motherisk update. Can Fam Phys 1997;43:1055-7
5. Lacroix R, Eason E, Melzack R. nausea and vomiting during pregnancy: a prospective study of its frequency, intensity and patterns of change. AM J Obstet Gynecol 2000; 182:931-7
6. Sweet B. (Ed). (1999).Mayes’ midwifery: A textbook for midwives (12th ed.). Bailliere Tindall. London.
7. Fischer-Rasmussen W, Kajaer SK, Dahle C et al. Ginger treatment of hyperemesis gravidarum. Eur J Obstet Gynecol Reprod Biology 1991; 38; 245-8
8. Vickers AJ. Can acupuncture have specific effects on health? A systematic review of acupuncture antiemesis trials, Journal of Reproductive Soc Med 1996; 89:303-11