Normal body temperature for men and women when measured orally, and lies between 98.2 ± 1.3 degree F. or 36.8 ± 0.7 degree C. Basal body temperature is the lowest body temperature that is attained during sleep. For the sake of convenience, it is measured immediately after awakening in the morning, before starting any activity.
Basal body temperature charting is helpful for women who are eagerly looking forward to getting pregnant soon, or all women who want to avoid pregnancy. It is a fact that the basal body temperature of a woman rises slightly after ovulation, when the woman is most fertile. The rise in temperature after ovulation is attributed to the release of the hormone progesterone by the ovarian follicles. Let us first take a look at the normal temperature fluctuations at the start of pregnancy.
Body Temperature After Conception
Before ovulation, the basal body temperature of a woman can be anywhere between 96.0 and 97.5 degrees Fahrenheit. When ovulation takes place, the temperature of the body rises by around 0.4 to 0.6 degrees. If the woman succeeds in conceiving during this period, then the temperature remains elevated. If fertilization does not take place, then the body temperature drops again and the body starts preparing for menstruation.
The hormones estrogen and progesterone play an important role in temperature fluctuations in the body of a woman. The hormonal changes lead to hot flashes which result in increased body temperature. As ovulation occurs in the middle of the menstrual cycle, slightly higher temperature for the next 18 days is considered as an early sign of pregnancy before missed period.
Lower than Normal Body Temperature During Pregnancy
Immediately after conception, the body starts preparing for the safety of the fetus. Various hormonal changes take place in the body as the body now needs to take care of the growing fetus, uterus and placenta. The blood production increases and new blood vessels network develops. The rate of metabolism increases significantly. This leads to a slight rise in the body temperature of the pregnant woman.
The increased activity in the body and increased hormonal levels are responsible for slightly elevated body temperature that is normally experienced by pregnant women. But very high temperature (fever) can prove to be harmful for the fetus and the mother. A temperature of more than 100.4 degrees Fahrenheit needs immediate medical attention. Very high fever (a temperature of more than 102 degrees Fahrenheit) is considered as a serious situation.
Body temperature below 95 degrees is considered as serious. Low body temperature after conception indicates low progesterone level. This increases the risk of miscarriage. Anemia can lead to low body temperature during pregnancy. As the body demands more nutrients during pregnancy, women are likely to develop anemia. Anemia develops due to iron deficiency or due to presence of a disease. Along with low body temperature, a pregnant woman may experience weakness, headache, pale skin, dizziness, extreme fatigue, as symptoms of anemia.
Other causes of persistent low temperature include:
- Under-active thyroid (hypothyroidism)
- Adrenal gland insufficiency (Addison's disease)
- Hypothalamus dysfunction
- Liver problems
- Kidney diseases
- Widespread infection (sepsis)
- Excessive use of alcohol or illicit drugs
- Side effects of certain medications
- Excessive exposure to cold
- Hypoglycemia (low blood sugar)
- Starvation, malnutrition
- Hypopituitarism (slow function of the pituitary gland)
- Vasoconstriction failure
- Uremia (accumulation of nitrogenous waste products in the blood.
- Diabetic ketoacidosis
- Carbon monoxide poisoning
- Shock, unbearable stress
If a woman notices decreased body temperature during pregnancy, she should consult her doctor immediately. The underlying condition can prove to be life-threatening for the mother and the baby.