Dr.Raghad Abdul-Halim

 Nausea and vomiting affect up to 50% of pregnant women. The onset of symptoms is usually early in the first trimester at around 5-6 weeks gestation, this is called morning sickness.  Most of women are able to maintain fluid and nutrient intake by dietary modification and the symptoms will resolve by the end of the 1 st trimester.

 Definition: H.G. is nausea and vomiting of pregnancy when the woman is unable to maintain adequate hydration and nutrition, either because of severity or duration of symptoms.  The severe and protracted vomiting is associated with marked weight loss, muscle wasting, ketonuria, dehydration, and electrolyte disturbance including hypokalemia and metabolic hypochloremic alkalosis.

Incidence: affects 0.5-2% of all pregnancies.  A common associated symptom is ptyalism- excess salivation and the inability to swallow saliva, an increased olfactory and gustatory aversion. Some discrete measures of severity, the most commonly accepted criterion being loss of 5% of pre-pregnancy weight.

 H.G. is clearly related to a product of placental metabolism since it does not require the presence of the fetus.  Strong temporal association between hCG level and the time course of nausea and vomiting of pregnancy.  There is association of biochemical hyperthyroidism with the severity of nausea and vomiting of pregnancy. The thyroid stimulator of pregnancy is hCG (hCG can stimulate TSH receptors in the thyroid gland).  Higher level of maternal estradiol.  Certain cytokines is seen to be increased in patients with H.G. such as TNF-α.  Genetic predisposition of mother (family history seen in monozygotic twin, or in mother).

 Family history.  Female gender of fetus.  History of migraine.  Multiple gestations.  Down syndrome.  Molar pregnancy.  Note: Smoking decrease nausea and vomiting of pregnancy because it is associated with decreased concentration of hCG and estradiol.

History and Examination:  The onset of H.G. is always in the 1 st trimester, in addition to nausea and vomiting and weight loss, women often report ptylism, there may be signs of dehydration including postural hypotension and tachycardia.  H.G. is a diagnosis of exclusion and it is important to make athorough clinical assessment and to ensure that investigations are performed for common and serious causes of vomiting.

An ultrasound of the uterus should be performed to:  Confirm that woman is pregnant.  To establish the number of fetus/fetuses (to exclude multiple pregnancy).  To exclude hydatidiform mole. Laboratory investigation commonly reveals hyponatremia, hypokalemia, raised hematocrit. Ketonuria is frequently present. A biochemical hyperthyroidism with raised free T4 and decreased TSH (which is transient and not require specific treatment) may also be present. Women with biochemical hyperthyroidism examined carefully, we should ask about weight loss, diarrhea, tachycardia prior to pregnancy, examined for goiter, and checked for thyroid antibodies

Other possible causes of N & V should be excluded like ;  UTI so we should send patients for mid stream urine test and urine for culture & sensitivity, urea & electrolyte.  cholecystitis.  gastritis.  peptic ulcer.  torsion of ovarian cyst.  diabetic keto-acidosis.  intracranial tumors.

1.Maternal Risks: serious maternal morbidity and mortality may result if H.G. not managed correctly.  Wernick's encephalopathy (diplopia, nystagmus, ataxia, and confusion) can develop as a result of thiamine (Vitamine B1) deficiency, which if untreated may result in Korsakofs' psychosis (amnesia, impaired ability to learn) or death.  Other vitamins deficiencies may occur for example peripheral neuropathy and anemia resulting from vitamin B12, B6 deficiency.  Hyponatremia can cause confusion, seizures and respiratory arrest, and if not treated too rapidly can cause pontine myelinolysis.  Deep venous thrombosis (DVT): resulting from dehydration and reduced mobility.  Mallory-Weiss tear in the esophagus due to prolong vomiting.

2. Fetal risks: infants of mothers with severe H.G., abnormal biochemical tests, weight loss have been reported to have lower birth weights.

1. Rehydration and Vitamin Supplementation:  Fluid replacement therapy should be with either normal saline (NaCl 0.9%) or Hartmanns' solution (NaCl 0.6%). Dextrose containing fluids should not be used because it they do not contain sufficient Sodium to correct hyponatremia and Wernicks' encephalopathy can be precipitated by intravenous dextrose and carbohydrate rich foods (because the small amount of thiamine remaining may be consumed in the acute metabolism of carbohydrate load).  Normal saline 1L mmol KCl 8 hourly.  Thiamine supplements should be given in a daily dose of mg tds. Monitoring of urine output and dipstick to assess ketonuria should be done.

 Vitamin B mg tds is recommended 1 st.  if symptoms persists we can add anti-histamines like (doxylamine 10 mg, diphenhydranate mg 6 hourly).  if symptoms persists we can add phenothiasine (prochlorperazine-stimitil- 25mg twice daily) or dopamine antagonist-metoclopromide-5-10 mg 8 hourly orally or intravenously.  If all these measures fail then short course of corticosteroids which are a potent antiemetic in a form of methylprednisolone 16 mg 3 times daily for 3 days and then tapered to the lowest effective dose for a period not exceeding 6 weeks, most patients will respond to this treatment.  Corticosteroids appear to increase the risk of facial clefts slightly when given in the 1 st trimester, other commonly used antiemetic are not known teratogens.

 Advice the patient to eat small portions of whatever seems palatable whenever symptoms allow. Proteins are better tolerated than fat and carbohydrates, liquid meals are better than solid, sometimes change in location or separation from home has some benefit in decreasing symptoms.  In few cases when the patient does not respond adequately to therapy and is unable to maintain their weight by oral intake, nutritional support is required either by:  Enteral nutrition: supplementation using naso- gastric tube.  Parenteral nutrition: has complication of sepsis, thrombophlebitis, pericardial temponade.

The best approach to H.G. management is by prevention:  Taking multivitamins at the time of conception and early pregnancy are less likely to require intervention later on.  Treatment of woman who has nausea and vomiting sufficient to interfere with their daily routine is associated with lower rate of hospital admission for H.G.