Mild nausea and vomiting in pregnancy is a common problem affecting 3% of pregnancies. It is probably due to the hormonal changes that occur in pregnancy and curiously its presence, if mild, is associated with a slightly better outcome. A small percentage of women will experience repeated vomiting which can result in weight loss, disturbance in the balance of minerals and other nutritional deficiencies. This situation is termed hyperemesis gravidarum, HG, which typically develops between the fourth and sixth weeks of pregnancy and often improves by the twentieth week but may continue throughout the pregnancy.
The risk of developing hyperemesis gravidarum is increased in younger women, multiple or female pregnancy, non-smokers, non-whites, if there is a family history of others being affected, previously affected pregnancies and if there is underlying gastrointestinal disease. Psychological factors are now thought to be much less important that they were.
Those with mild symptoms may benefit from:
However, severe vomiting in pregnancy that compromises food and fluid intake is a serious matter and requires medical attention, especially if any of the features below are present:
|Warning Features:||Potential Nutritional Significance|
|Weight loss >1lb per week or underweight at the commencement or during the pregnancy||Lack of energy intake and fetal growth retardation is possible|
|Lack of urine output and excessively low blood pressure that falls further on standing||Dehydration|
|Ketosis - a sweet slightly sickly smell to the breath or in the urine||Lack of carbohydrate and energy and if Persistent foetal growth retardation is possible|
|Profound fatigue||Lack of potassium, magnesium or vitamin B1|
|Mental confusion||Dehydration, lack of vitamin B1, sodium, potassium or magnesium imbalance|
|Double vision||Severe vitamin B1 deficiency|
|Loss of co-ordination||Severe vitamin B1 deficiency|
Any woman with these features requires urgent medical attention for assessment of possible medical causes including liver disease and thyrotoxicosis and is likely to require intravenous fluid replacement and urgent correction of energy and nutrient deficiencies.
If vitamin B1 – thiamine deficiency is suspected then treatment should be given without delay usually by intravenous/intramuscular injection and before results of laboratory tests are available.
Those involved in the care of such patients should refer to The Royal College of Physicians Report on Alcohol: Guidelines for Managing Wernicke’s Encephalopathy in the Accident and Emergency Department. Thomson AD, Cook CCH, Touquet R, Henry JA. Alcohol and Alcoholism Vol 37, No. 6, pp513-521, 2002.
www.cvsa.org.uk The Cyclical Vomiting Association