1stPregnant.com deals with
all facets of information about pregnancy in female humans. This
website does not deal with any other aspect of pregnancy such as
animals (non humans) etc.
Pregnancy can be defined as the female carrying one or more
offspring, referred to as a fetus or embryo, inside their
uterus. Multiple fetuses / embryo are how twins, triplets, or
more are born. Technically speaking, the term embryo is used to
describe the developing offspring during the first eight weeks
following conception, and the term fetus is used from about two
months of development until birth.
Often, human pregnancy is arbitrarily divided into three
trimester periods. These three divisions reference the different
stages of prenatal development.
During the first trimester is when the highest risk of a
miscarriage, the act of natural death or embryo or fetus. Within
the second trimester is the ability to monitor and diagnosed of
the fetus. At the start of the third trimester the fetus can be
evaluated for the ability to survive with or without medical
help outside the uterus.
Estimating the date of birth is done in several easy
calculations. An expected delivery date (EDD) is calculated at
40 weeks counting from the last menstrual period (LMP). Another
way to calculate an expected delivery date is 38 weeks from the
day of conception.
More complicated methods of determining expected delivery
date is available and they take into consideration such items as
if this is your first child, ethnicity, length of menstrual
cycle, menstrual regularity, parental age, weather and many
When the pregnancy has attained 37 complete weeks, but is less
than 42 weeks, it is referred to as “at term.” The time prior to
37 weeks, 259 days, is referred to as pre-term and from week 42,
294 days, the term is called post-term and this is when there
are elevated risks for mother and fetus are significant.
Commonly, obstetricians prefer to induce labor in a non
complicated pregnancy at some time between 41 and 42 weeks.
Whichever calculation you prefer to use, the average number of
births on the expected delivery date is less than 5%. On
average, 50% of births occur within a week of expected delivery
date and 90% of births occur within two weeks of expected
Please remember, pre and post terms are used to calculate time
of pregnancy, and the terms premature and postmature have
historical meanings and relate more to the size of the infant
and their development.