Basal body temperature

Last updated
Basal body temperature
Background
Type Fertility awareness
First use1930s
Failure rates (first year)
Perfect useUnknown% [1]
Typical useUnknown% [1]
Usage
ReversibilityImmediate
User remindersDependent upon strict user adherence to methodology
Clinic reviewNone
Advantages and disadvantages
STI protectionNo
Period advantagesPrediction
Weight gainNo
BenefitsNo side effects, can aid pregnancy achievement

Basal body temperature (BBT or BTP) is the lowest body temperature attained during rest (usually during sleep). It is usually estimated by a temperature measurement immediately after awakening and before any physical activity has been undertaken. This will lead to a somewhat higher value than the true BBT.

Contents

In women, ovulation causes a sustained increase of at least 0.2 °C (0.4 °F) in BBT. Monitoring BBTs is one way of estimating the day of ovulation. The tendency of a woman to have lower temperatures before ovulation, and higher temperatures afterwards, is known as a biphasic temperature pattern. Charting this pattern may be used as a component of fertility awareness. The BBT of men is comparable to the BBT of women in their follicular phase. [2]

Hormonal causes of biphasic patterns

The higher levels of estrogen present during the pre-ovulatory (follicular) phase of the menstrual cycle lower BBTs. The higher levels of progesterone released by the corpus luteum after ovulation raise BBTs. [3] After ovulation, the temperature will be raised by at least 0.2 °C (0.4 °F), for at least 72 hours, compared to the previous six days. [3]

As a birth control method

While avoiding pregnancy

Charting of basal body temperatures is used in some methods of fertility awareness, such as the sympto-thermal method, and may be used to determine the onset of post-ovulatory infertility. [4] When BBT alone is used to avoid a pregnancy, it is sometimes called the Temperature Rhythm method. [4]

Basal body temperature alone is most effective at preventing pregnancy if the couple abstains from intercourse from the beginning of menstruation through the third day after the basal body temperature has risen. [5] BBTs only show when ovulation has occurred; they do not predict ovulation. Sperm typically lasts for at least three days and can survive as long as a week, [3] making prediction of ovulation several days in advance necessary for avoiding pregnancy.

Effectiveness

There is limited evidence about the effectiveness of fertility awareness family planning methods, some of which use basal body temperature as one component. [1] About 24% of women who use any type of fertility awareness program become pregnant during the first year, compared to about 85% of sexually active women who are not trying to prevent a pregnancy. [6] [5]

The World Health Organization ranked fertility awareness methods, taken as a whole, as an "effective" method of preventing pregnancies. [5] The WHO placed fertility awareness methods in the third tier of effectiveness, after "most effective" methods such as IUDs and "very effective" methods such as combined oral contraceptive pills. [5] [7]

Trying to conceive

Couples that are trying to conceive can use BBT to determine when the opportunity for a pregnancy during this cycle has passed.

As a diagnostic test

For infertility

Infertility due to lack of ovulation is common. BBT charts can be used to identify when and whether ovulation is taking place. [3]

Regular menstrual cycles are often taken as evidence that a woman is ovulating normally, and irregular cycles is evidence she is not. However, many women with irregular cycles do ovulate normally, and some with regular cycles are actually anovulatory or have a luteal phase defect. Records of basal body temperature can be used to accurately determine if a woman is ovulating. [8]

For estimating the timing of childbirth

Calculating the expected due date for a pregnancy based upon the self-reported last menstrual period is less accurate than calculating it based upon either BBT or ultrasound. [8]

Related Research Articles

<span class="mw-page-title-main">Emergency contraception</span> Birth control measures taken after sexual intercourse

Emergency contraception (EC) is a birth control measure, used after sexual intercourse to prevent pregnancy.

<span class="mw-page-title-main">Fertility awareness</span> Methods to determine menstrual phases

Fertility awareness (FA) refers to a set of practices used to determine the fertile and infertile phases of a woman's menstrual cycle. Fertility awareness methods may be used to avoid pregnancy, to achieve pregnancy, or as a way to monitor gynecological health.

<span class="mw-page-title-main">Combined oral contraceptive pill</span> Birth control method which is taken orally

The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as "the pill", is a type of birth control that is designed to be taken orally by women. It is the oral form of combined hormonal contraception. The pill contains two important hormones: a progestin and estrogen. When taken correctly, it alters the menstrual cycle to eliminate ovulation and prevent pregnancy.

Calendar-based methods are various methods of estimating a woman's likelihood of fertility, based on a record of the length of previous menstrual cycles. Various methods are known as the Knaus–Ogino method and the rhythm method. The standard days method is also considered a calendar-based method, because when using it, a woman tracks the days of her menstrual cycle without observing her physical fertility signs. The standard days method is based on a fixed formula taking into consideration the timing of ovulation, the functional life of the sperm and the ovum, and the resulting likelihood of pregnancy on particular days of the menstrual cycle. These methods may be used to achieve pregnancy by timing unprotected intercourse for days identified as fertile, or to avoid pregnancy by avoiding unprotected intercourse during fertile days.

<span class="mw-page-title-main">Menstrual cycle</span> Natural changes in the human female reproductive system

The menstrual cycle is a series of natural changes in hormone production and the structures of the uterus and ovaries of the female reproductive system that makes pregnancy possible. The ovarian cycle controls the production and release of eggs and the cyclic release of estrogen and progesterone. The uterine cycle governs the preparation and maintenance of the lining of the uterus (womb) to receive an embryo. These cycles are concurrent and coordinated, normally last between 21 and 35 days, with a median length of 28 days. Menarche usually occurs around the age of 12 years; menstrual cycles continue for about 30–45 years.

<span class="mw-page-title-main">Ovulation</span> Release of egg cells from the ovaries

Ovulation is the release of eggs from the ovaries. In women, this event occurs when the ovarian follicles rupture and release the secondary oocyte ovarian cells. After ovulation, during the luteal phase, the egg will be available to be fertilized by sperm. In addition, the uterine lining (endometrium) is thickened to be able to receive a fertilized egg. If no conception occurs, the uterine lining as well as the egg will be shed during menstruation.

<span class="mw-page-title-main">Dysmenorrhea</span> Pain during and sometimes before menstruation

Dysmenorrhea, also known as period pain, painful periods or menstrual cramps, is pain during menstruation. Its usual onset occurs around the time that menstruation begins. Symptoms typically last less than three days. The pain is usually in the pelvis or lower abdomen. Other symptoms may include back pain, diarrhea or nausea.

Anovulation is when the ovaries do not release an oocyte during a menstrual cycle. Therefore, ovulation does not take place. However, a woman who does not ovulate at each menstrual cycle is not necessarily going through menopause. Chronic anovulation is a common cause of infertility.

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<span class="mw-page-title-main">Lactational amenorrhea</span> Post-partum infertility due to breast feeding

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<span class="mw-page-title-main">Hormonal contraception</span> Birth control methods that act on the endocrine system

Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The original hormonal method—the combined oral contraceptive pill—was first marketed as a contraceptive in 1960. In the ensuing decades, many other delivery methods have been developed, although the oral and injectable methods are by far the most popular. Hormonal contraception is highly effective: when taken on the prescribed schedule, users of steroid hormone methods experience pregnancy rates of less than 1% per year. Perfect-use pregnancy rates for most hormonal contraceptives are usually around the 0.3% rate or less. Currently available methods can only be used by women; the development of a male hormonal contraceptive is an active research area.

Controlled ovarian hyperstimulation is a technique used in assisted reproduction involving the use of fertility medications to induce ovulation by multiple ovarian follicles. These multiple follicles can be taken out by oocyte retrieval for use in in vitro fertilisation (IVF), or be given time to ovulate, resulting in superovulation which is the ovulation of a larger-than-normal number of eggs, generally in the sense of at least two. When ovulated follicles are fertilised in vivo, whether by natural or artificial insemination, there is a very high risk of a multiple pregnancy.

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<span class="mw-page-title-main">Intrauterine device</span> Form of birth control involving a device placed in the uterus

An intrauterine device (IUD), also known as intrauterine contraceptive device or coil, is a small, often T-shaped birth control device that is inserted into the uterus to prevent pregnancy. IUDs are a form of long-acting reversible birth control (LARC).

<span class="mw-page-title-main">CycleBeads</span> Visual tool used for family planning

CycleBeads is a visual tool that was developed by the Institute for Reproductive Health at Georgetown University. This device helps women use the Standard Days Method, a fertility awareness-based family planning method.

<span class="mw-page-title-main">Fertility testing</span>

Fertility testing is the process by which fertility is assessed, both generally and also to find the "fertile window" in the menstrual cycle. General health affects fertility, and STI testing is an important related field.

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Hormonal oral contraceptives are preventive medications taken orally to avoid pregnancy in sexually active active females by manipulating their sex hormones. The first oral contraceptive was approved by the FDA and sold to the market in 1960. There are two types of hormonal oral contraceptives, namely Combined Oral Contraceptives and Progesterone Only Pills. Oral contraceptives, be it combined or progesterone-only, can effectively prevent pregnancy by regulating hormonal changes in the menstrual cycle, inhibiting ovulation, and altering cervical mucus to impede sperm mobility; combined pills have extra effects in menstrual cycle regulation and menstrual pain relief. Common off-label uses include menstrual suppression and acne relief, with Combined Oral Contraceptives having additional benefits in relieving menstrual migraine.

References

  1. 1 2 3 Grimes DA, Gallo MF, Halpern V, Nanda K, Schulz KF, Lopez LM (2004). "Family planning with methods based on fertility awareness | Cochrane". Cochrane Database of Systematic Reviews. 2004 (4): CD004860. doi:10.1002/14651858.CD004860.pub2. PMC   8855505 . PMID   15495128.
  2. Baker, Fiona C.; Waner, Jonathan I.; Vieira, Elizabeth F.; Taylor, Sheila R.; Driver, Helen S.; Mitchell, Duncan (2001-02-01). "Sleep and 24 hour body temperatures: a comparison in young men, naturally cycling women and women taking hormonal contraceptives". The Journal of Physiology. 530 (3): 565–574. doi:10.1111/j.1469-7793.2001.0565k.x. ISSN   1469-7793. PMC   2278431 . PMID   11158285.
  3. 1 2 3 4 Coward, Kevin; Wells, Dagan (2013-10-31). Textbook of Clinical Embryology. Cambridge University Press. pp. 145, 156. ISBN   9780521166409.
  4. 1 2 Grimes, David A.; Gallo, Maria F.; Halpern, Vera; Nanda, Kavita; Shulz, Kenneth F.; Lopez, Laureen M. (October 2004). "Fertility awareness‐based methods for contraception". Cochrane Database of Systematic Reviews. 2004 (4): CD004860. doi:10.1002/14651858.CD004860.pub2. PMC   8855505 . PMID   15495128.
  5. 1 2 3 4 Cunningham, F. Gary (2014). Williams Obstetrics (24th ed.). New York: McGraw-Hill Education/Medical. pp. 696, 713. ISBN   9780071798938. OCLC   871619675.
  6. Trussell, James (2011). "Contraceptive failure in the United States". Contraception. 83 (5): 397–404. doi:10.1016/j.contraception.2011.01.021. ISSN   0010-7824. PMC   3638209 . PMID   21477680.
  7. Family planning : a global handbook for providers : evidence-based guidance developed through worldwide collaboration. Baltimore: Johns Hopkins, Bloomberg School of Public Health, Center for Communication Programs, INFO Project. 2011. ISBN   9780978856304. OCLC   776090067.
  8. 1 2 Taylor, Robert B. (2012-12-06). Taylor's Family Medicine Review. Springer Science & Business Media. p. 40. ISBN   9781461221524.