Human Pregnancy Articles about
Pregnancy
Website Links For
Pregnancy
 

Information About

Human Pregnancy




Pregnancy is the carrying of one or more Embryo s or Fetuses by Female Mammal s, including humans, inside their bodies. In a pregnancy, there can be multiple Gestation s (for example, in the case of Twins , or Triplets ). Human pregnancy is the most studied of all Mammalian Pregnancies .

Human pregnancy lasts approximately 40 weeks between the time of the last ; similarly, the terms Para 0 , Para 1 and so on are used for the number of times a woman has given birth.

In many societies' medical and legal definitions, human pregnancy is arbitrarily divided into three Trimester periods, as a means to simplify reference to the different stages of fetal development. The first trimester period carries the highest risk of Miscarriage (natural death of embryo or fetus). During the second trimester the development of the fetus can start to be monitored and diagnosed. The third trimester marks the beginning of Viability , which means the fetus can survive if an early natural or induced birth occurs. Because of the possible viability of developed fetus, cultural and legal definitions of life often consider a fetus in the third trimester to be a distinct living Person .

:''See also Pregnancy Terms And Definitions


DETECTION AND DATING

The beginning of pregnancy may be detected in a number of ways, including various pregnancy tests which detect hormones generated by the newly-formed Placenta . Clinical blood and urine tests can detect pregnancy as early as 6-8 days after date of conception. Home Pregnancy Test s are personal urine tests, which normally cannot detect a pregnancy until at least 12-15 days after conception. Both clinical and home tests can only detect the state of pregnancy, and cannot detect the actual date of conception.

In practice, doctors typically determine a date for conception (i.e. an "age" for an Embryo ) by the "menstrual date" based on the first day of a woman's last menstrual period, as the woman reports it. Unless a woman's recent Sexual activity has been limited, the exact date of conception or implantation are unknown. And absent any symptoms of Morning Sickness , often the only visible sign of a pregnancy is an interruption of her normal monthly menstruation cycle, (i.e. a "late period"). Hence, the "menstrual date" is simply a common educated estimate for the age of a fetus, which is an average of two weeks later than the first day of the woman's last menstrual period. (The Margin Of Error considers 0 to 30 days after last menstruation, hence a 14 day average.) The term "conception date" may sometimes be used when that date is more certain, though even medical professionals can be imprecise with their use of the two distinct terms. An unknown date for conception means that in practice the distinction between embryo and fetus is a clinical one only, and not used as to refer to stages of development of a particular pregnancy.
You calculate the due date either with Naegele's Rule or by using an online pregnancy calculator and calendar.


There are likewise finer distinctions between the concepts of fertilization ( Conception ) and the actual state of pregnancy. In a normal pregnancy, the Fertilization of the egg usually will have occurred in the Fallopian Tube s or in the Uterus . (In women with Fertility Problems , an egg may become fertilized yet fail to become implanted in the uterus.) If the pregnancy is the result of In-vitro Fertilization the fertilization will have occurred in a Petri Dish , after which "pregnancy" begins when one or more zygotes implant after being transferred by a Physician in the woman's uterus.


In the context of political debates regarding a proper Definition Of Life , the terminology of pregnancy can be confusing. Because precise assessment of a pregnancy as being at the "embryo" or "fetus" stage is usually undeterminable, the terms (though more clinically precise) are less commonly used than terms like "baby" or "child." The medically and politically neutral term which remains is simply "pregnancy," though this can be problematic as it only refers indirectly to the embryo or fetus. In the context of personal treatment, Bedside Manner generally dictates that doctors make sparse use of clinical language like "fetus" and "embryo," and instead simply refer to the developing child as a " Baby ."




TIMELINE OF A TYPICAL PREGNANCY


Pregnancy is typically broken into three periods, or trimesters, each of about three months. While there are no hard and fast rules, these distinctions are useful in describing the changes that take place over time.


First trimester


Fertilization

See Also: Fertilization


Before pregnancy begins, a female Oocyte ( Egg ) must be fertilized, by male Sperm in a process referred to in medicine as "fertilization", or commonly as "conception". In most cases, this occurs through the act of sexual intercourse, in which a man ejaculates inside of a woman, thus releasing his sperm inside of her. Though pregnancy technically begins at implantation, it is often convenient to date from the first day of a woman's last menstrual period. This is used to calculate the Estimated Date of Delivery (EDD).

Traditionally (according to , while babies born after the 43 week mark are considered Postmature .

However, the average length of pregnancy depends on various factors. For example, the first pregnancy tends to last longer than subsequent pregnancies.

An accurate date of conception is important, because it is used in calculating the results of various Prenatal Tests (for example, in the Triple Screen Test ). A decision may be made to Induce labour if a baby is perceived to be overdue. Due dates are only a rough estimate, and the process of accurately dating a pregnancy is complicated by the fact that not all women have 28 day menstrual cycles, or ovulate on the 14th day following their last menstrual period. Approximately 3.6% of all women deliver on the due date predicted by LMP, and 4.7% give birth on the day predicted by ultrasound.


Implantation


In medicine, pregnancy is defined as beginning when the developing , for the purpose of receiving essential Nutrients through the Uterus wall. The Umbilical Cord in a newborn child consists of the remnants of the connection to the placenta. The developing embyro undergoes tremendous growth and changes during the process of Embryonic And Fetal Development .
Morning Sickness aflicts about half of all pregnant women, typically only in the first trimester.


Second trimester


Most women feel more energised in this period, and begin to seriously put on weight. The first movement of the fetus, often referred to as "quickening", can be felt, as it begins to form into a recognisable shape.


Third trimester

Final weight gain takes place, and the fetus begins to move regularly. This can be uncomfortable, causing symptoms like weak bladder control and back-ache.


MEDICAL ASPECTS OF PREGNANCY

See Also: Obstetrics


Diagnostic criteria are: In a woman who has regular menstrual cycles and is sexually active, a period delayed by a few days or weeks is suggestive of pregnancy; elevated B-hcG to around 100,000 mIU/mL by 10 weeks of gestation.


BIRTH

See Also: Childbirth


Childbirth is the process in which the baby is born. It is considered by many to be the beginning of a person's life, where age is defined relative to this event in most cultures.

A woman is considered to be in labour when she begins experiencing regular painful uterine contractions, accompanied by changes of her cervix — primarily effacement and dilation. While childbirth is widely experienced as painful, some women do report painless labours. Most women are capable of having a normal birth. However, sometimes complications arise and a woman may need to undergo a Caesarean Section


POSTNATAL PERIOD

See Also: Postnatal


For topics following on from a successful pregnancy and birth, see:


TERMS AND DEFINITIONS


Technical


  • ''embryo'' - conceptus between time of fertilization to 10 weeks of gestation

  • '' FASD '' - Fetal Alcohol Spectrum Disorder, a clinical term for the effects alcohol can have on the developing fetus

  • ''fetus'' - from 10 weeks of gestation to time of birth

  • ''Ga Pw-x-y-z'' - a = number of pregnancies, w = number of term births, x = number of preterm births, y = number of miscarriages, z = number of living children; for example, G4P1-2-1-3 means the woman had a total of 4 pregnancies, of which 1 is of term, 2 are preterm, 1 miscarriage, and 3 total living children (1 term + 2 preterm).

  • '' gestational age '' - time from last menstrual period (LMP) up to present

  • ''gravidity (G)'' - number of times a woman has been pregnant

  • ''infant'' - time of birth to 1 year of age

  • ''parity (P)'' - number of pregnancies with a birth beyond 20 weeks GA or an infant weighing more than 500 g

  • ''preterm infant'' - delivered between 24-37 weeks

  • ''previable infant'' - delivered prior to 24 weeks

  • ''term infant'' - delivered between 37-42 weeks

  • ''first trimester'' - up to 14 weeks of gestation

  • ''second trimester'' - 14 to 28 weeks of gestation

  • ''third trimester'' - 28 weeks to delivery

  • ''viability'' - minimum age for fetus survival, ca. third trimester

  • ''zygote'' - from fertilization until second cell division



Colloquial


There are a number of colloquialisms for pregnancy, usually regional. The action of impregnating a woman or girl is called 'knocking (her) up' in Canada and some parts of the U.S., and the state of being pregnant 'knocked-up'. The term 'lady-in-waiting', meaning a pregnant woman, is used broadly in the U.S. The word 'gone' or 'along' is used to represent gestational time, e.g. 'she's really far gone' or 'about 6 weeks gone' or 'six months along'. In the southern U.S. the euphemism of a water Well is occasionally used to represent pregnancy (e.g. 'drink out of the well', to become pregnant), and a baby almost ready to be delivered is 'on his/her road'. Eastern Seaboard slang describes the woman as being 'in a fix' or, occasionally, 'preggers'; the Southern U.S. equivalent is 'in the family way'. An alternate term not slang or colloquial is 'with child'. 'Having a bun in the oven' is another frequently used phrase to indicate that a woman is pregnant.
Pregnant can also mean 'having many possibilities or implications.'


SEE ALSO




REFERENCE