Vomiting in the 3rd third
For nausea and vomiting in late pregnancy, the causes are often not identified. Probably the strain on the mother, which increases to its maximum in the last three months, plays an important role. Likewise, hormonal changes occur again at the end of the pregnancy, which can cause reactions in various body systems.
Although simple vomiting is a great burden for expectant mothers, the treatment is usually relatively simple. As a rule, the phase of vomiting is waited for and at most the nausea is prevented.This is possible through different nutrition and diet plans, where one focuses on gentle food and small meals, which are distributed throughout the day. In addition the pregnant woman should do without beverages, which load the stomach additionally, like coffee or liquids with carbonic acid.
Ginger tea, on the other hand, is recommended by many women who suffer from pregnancy vomiting. An alternative medical treatment has also become established over the years – acupuncture or acupressure. Needles and massages are used to influence various systems in the body.
The scientific background could not yet be clarified, but the results speak for themselves with a relief of symptoms in 50% of cases. Only very rarely, preferably in cases of very severe nausea, are drugs against vomiting used here, as the side effects and contraindications must always be taken into account. In cases of severe hyperemesis gravidarum it is not possible to wait for the disease to subside.
The patient can quickly slip into a critical state of undersupply, in which the unborn child is also harmed. Therefore the administration of fluid and electrolyte solutions in combination is the method of choice. This cannot be done on an outpatient basis, i.e. not at home, which makes hospitalization necessary.
In addition, nutrition can be administered there with the aid of a stomach tube, which reduces the risk of vomiting. During an in-patient stay, a fluid balance should always be carried out: it is recorded what fluid the patient has taken in (by drinking or via an infusion) and given out (urine). Most drugs can pass the placental barrier (a kind of cell barrier separating the infant’s and mother’s blood) and thus also have an effect on the fetus.
Since this is usually unnecessary, since the treatment of the mother is the primary focus, any kind of medication should be avoided due to its effect as well as possible side effects. Exceptions to this rule are various medications which, if they are not taken, pose a risk to the mother’s well-being. Especially in the first trimester, i.e. in the first third of the pregnancy, the unborn child is particularly sensitive and reacts sensitively to various substances foreign to the body.
Especially during this time, when unfortunately morning sickness occurs, medication should be avoided. Only if the mother is no longer responsible for the strain and stress and a change in diet has not been successful, can medication be used to alleviate the symptoms, so-called antiemetics. Antihistamines such as diphenhydramine or doxylamine are used as antiemetics.
These are H1-receptor antagonists, i.e. they block the binding site at a histamine receptor, which can mediate nausea and vomiting when activated. The antihistamines are widely used to treat motion sickness or pregnancy vomiting and are considered safe for the fetus. Another drug that is often used for vomiting of any kind, including pregnancy, is dimenhydrinate (more commonly known as Vomex®).
It is composed of diphenhydramine and another active ingredient. In severe cases of hyperemesis it can also be used on stronger drugs like ondansetron. Ondansetron is a 5-HT3 receptor antagonist and thus blocks the receptor for serotonin, which when activated has a similar effect to the histamine receptor.
Metoclopramide, as a dopamine antagonist, relieves nausea and increases gastrointestinal motility, which may also be beneficial. In addition to the above-mentioned agents, various anticholinergics, inhibitors of the cholinergic system, can also be administered. Most of the drugs that are suitable for the treatment of vomiting or hyperemesis have side effects.
However, these are usually mild, such as fatigue. The administration of vitamin B6 (pyridoxine) in the form of vitamin preparations, as well as independent absorption through various foods, can significantly alleviate the symptoms. A consistently increasing dose up to between 10 and 25 mg per day should be aimed for.
Since the intake of vitamins through food should be preferred in principle, it can be additionally supported by preparations if not enough nutrients can be taken orally due to nausea. The benzodiazepine diazepam has also been shown to have a positive effect on hyperemesis gravidarum. Diazepam is a psychotropic drug which has an anxiety-relieving, muscle-relaxing, but also sedative effect.According to experts, the latter component is responsible for the soothing properties regarding vomiting.
However, since diazepam is a long-term addictive drug and its teratogenic (harmful to the unborn child) effect has often been discussed, the drug should only be used when absolutely necessary, with the utmost caution and under medical supervision. Hydrocortisone and other corticosteroids may be used in cases of severe pregnancy vomiting which have so far proved resistant to therapy. Here too, a harmful effect on the child is being discussed.
There are also drugs which have an antiemetic effect, but which must not be administered during pregnancy and are therefore contraindicated. NK1-receptor antagonists, for example, act directly in the brain on the nausea center and thus prevent the development of nausea stimuli, but must not be taken by pregnant women. Preparations such as aprepitant or fosaprepitant should be avoided. The teratogenicity of domperidone, a dopamine antagonist like metoclopramide, has not been proven. Nevertheless, many doctors recommend not to take drugs containing the active substance.
