(latin graviditas) is the carrying of one or more offspring, known
as a fetus or embryo, inside the uterus of a female. In a pregnancy,
there can be multiple gestations, as in the case of twins or
Traditionally, doctors have measured pregnancy from a number of
convenient points, including the day of last menstruation,
ovulation, fertilization, implantation and chemical detection. In
medicine, pregnancy is often defined as beginning when the
developing embryo becomes implanted into the endometrial lining of a
woman's uterus. In some cases where complications may have arisen,
the fertilized egg might implant itself in the fallopian tubes or
the cervix, causing an ectopic pregnancy. Most pregnant women do not
have any specific signs or symptoms of implantation, although it is
not uncommon to experience minimal bleeding at implantation. Some
women will also experience cramping during their first trimester.
This is usually of no concern unless there is spotting or bleeding
as well. After implantation the uterine endometrium is called the
decidua.The placenta which is formed partly from the decidua and
partly from outer layers of the embryo is responsible for transport
of nutrients and oxygen to, and removal of waste products from the
fetus. The umbilical cord is the connecting cord from the embryo or
fetus to the placenta.The developing embryo undergoes tremendous
growth and changes during the process of foetal development.
Morning sickness can occur in about seventy percent of all pregnant
women and typically improves after the first trimester.
In the first 12 weeks of pregnancy the nipples and areolas darken
due to a temporary increase in hormones.
Most miscarriages occur during this period.
Vaginal ultrasound to evaluate 1st trimester pregnancy