Describe The Three Developmental Stages

Pregnancy can be divided into three trimesters and three development phases. The three development stages are germinal stage, embryonic stage, and fetal stage. Each trimester lasts about three months, starting with conception. The entire pregnancy typically lasts about nine months from conception to birth.

During the first trimester, a lot of growing and developing occurs. The trimester starts with simple an egg and sperm and typically ends with developments such as organs and a heartbeat. The first trimester, lasting from week one to week twelve, includes the germinal and embryonic stage, as well as part of the fetal stage. During the germinal stage, a zygote multiples and moves along a woman’s fallopian tube and eventually ends up

So many zygotes are rejected that, “as many as one in five pregnancies end with the woman never being aware that conception has occurred” (Weiten Psychology:Themes and Variation 324). Implantation is a very important process that occurs during the first two to four weeks. During implantation, the embryo is embedded into the wall of the womb, where it will stay for the rest of the pregnancy. This is a very important process due to the fact that during implantation, the placenta is formed. Without the placenta, a baby would have no way of receiving nutrients and oxygen from its’ mother. The next major development after implantation is the development of many vital organs such as, the brain, the spinal cord, and the heart. The embryo is still very small, less than a ¼ of an inch, and is only visible through ultrasound. The embryo is however, beginning to look more human especially when fingers and toes begin to form. As for the mother,

It typically feels better during the second trimester as you become more comfortable and accustomed to the pregnancy. The second trimester lasts from months four to six and includes the fetal stage. During the second trimester the baby should develop hearing and the ability to move, along with growing breathing pathways and a more regular daily cycle. This movement should become more obvious to the mother, who should begin to feel the baby’s movements more often. The breathing pathway also helps the baby begin to swallows bits of amniotic fluid. The regular daily cycle, also called the circadian rhythm, helps keep the baby on a regular cycle of breathing, heart beat, and food intake. This regular heartbeat should be able to be heard by a stethoscope during the second trimester, particularly around weeks seventeen thru twenty. The baby should now have grown fine hair called lanugo on their head. This lanugo should cover their body by week nineteen. Their transparent skin should also change and should be “covered by a greasy white substance called “vernix,” which provides protection from the amniotic fluid” (“Prenatal Summary” www.ehd.org/prenatal-summary.php). The baby will begin to develop fat under the skin which diminishes the transparency of the skin will help keep them warm, especially when they are born. During the second trimester is also a major time for the development of the liver and