Fever and Pregnancy
Fever (from Greek therme-overheating) is the accumulation of excess heat in the man’s or animal’s body, the body temperature rise, caused by the external factors that affect the heat exchange. Hyperthermia occurs from extreme tension of physiological mechanisms of thermoregulation (sweating, skin vessels’ dilation, etc.), progresses steadily until the body temperature reaches 41-42 °C (106-108 °F) and peaks with a heat stroke, if nothing is done to manage it. Hyperthermia is accompanied by metabolic disorders or increase in metabolic rates, as well as by the dehydration and salt depletion, disturbed blood circulation and failure of supplying oxygen to the brain, causing excitement, cramps and fainting.
High temperature in hyperthermia is tolerated worse than in other febrile diseases. The development of hyperthermia causes increased heat production (for example, during the muscle work), disturbs the mechanisms of thermoregulation (anesthesia, intoxication, some diseases), and weakness (in children of the first years of life). Artificial hyperthermia is used to treat some nervous and chronic diseases with slow progression.
Can Running a Fever While I'm Pregnant Harm My Baby
The fever was first teratogen factor observed in animals. In consequence, the negative impact of high temperature on the pregnancy development was proved in humans, too. Fever can cause a wide range of deviations-from the death of the embryo and miscarriage to congenital malformations, the severity of which depends on the fever height and duration. The source of thermal damage can be an illness accompanied by high temperature, use of sauna or infrared cabin, as well as work in the conditions of hot production.
Febrile diseases are quite common, about 20 % of women have at least one temperature increase during the pregnancy. The high temperature becomes destructive if the body temperature rises by more than 1.5 degrees and persists for more than 8 hours, or episodes of hyperthermia repeat few times (as with regular visits to sauna). The researches have shown that this increase of body temperature occurs when staying in the hot sauna (> 100 degrees) for 15 minutes, or in the infrared cabin for 10 minutes.
The risk of the neural tube defect associated with high temperature, is approximately 10-14 %, and the risk is higher when visiting infrared cabins than when visiting saunas. Fever during pregnancy, especially during the formation of organs and systems of the fetus, has teratogen effects and increase the risk of fetal death, fetal resorption, occurrence of the central nervous system defects, anterior abdominal wall, cardiovascular system and extremities’ malformations.
It is believed, that hyperthermia greater than 38.5 °C lasting more than 24 hours in the first four weeks after the conception can cause disorders of the brain and facial skeleton formation. Similar symptoms at 4-7 weeks of pregnancy would rather cause abnormal formation of the facial skeleton, such as hypoplasia of the mid face, cleft upper lip and a cleft palate, micrognathia and microphthalmia.
Increase in temperature leads to a distortion of protein synthesis, causing capillary micro thrombosis in the embryo and placental infarction. All these mechanisms may cause the embryo’s death or congenital malformations. In addition, an increase in temperature triggers myometrium contractions, which may result in a premature birth. The damaging effects of high temperature vary on the pregnancy term and duration of heat exposure. In some cases, it is unclear whether the fever or the disease causing it is to blame. The severity of the specific disorders depends on the height of the fever, its duration and the pregnancy term. Another important factor, increasing the risk of having adverse consequences of overheating, is hereditary peculiarities (e.g., predisposition to thrombosis etc.).
We can draw a conclusion that the pregnant woman can't stay in a hot sauna for more than 10-15 minutes, they should avoid taking hot baths and working in hot conditions. If your pregnancy coincides with the season of the increased incidence of respiratory infections, it is better to get a flu vaccine. The most dangerous is thermal exposure at 4-14 weeks of pregnancy.