Prenatal Development & the Newborn

Prenatal Development In this section, we will be discussing the prenatal (before birth) development. This will include both the stages of development as well as the possible influences that can harm psychological and physical development.

Three Stages of Development Zygote: Conception to 2 weeks Embryo: 2 to 8 weeks Fetus: 8 weeks to birth

See the handout for the month by month physical development

Genetic Factors affecting the developing child Phenylketonuria (PKU): The absence of an enzyme known as phenylalanine hydroxylase. Normally, phenylalanine is broken down into tyrosine, which is used by the body. However, when phenylalanine hydroxylase is not produced by the body, phenylalanine builds up in the body, as is toxic to brain tissue. Phenylketonuria is easily determined in the first days of life, but undiagnosed children can develop severe mental disabilities and other neurological issues.

Sickle-cell anemia (SCA): An autosomal recessive disease resulting in the production of abnormal hemoglobin, the protein that carries oxygen in the blood. Too much abnormal hemoglobin can cause the blood cells to develop a sickle like shape, hence the name. It affects about 72,000 Americans, predominantly African American, and causes pain, anemia, and infections. There is currently no cure.

Tay-Sachs Disease (TSD): The inherited absence of an enzyme called hexosaminidase A, which causes a buildup of fatty lipids in the brain, damaging neural functioning. While the damage happens during fetal development, an affected baby seems normal until 5-6 months old. Over time, the baby loses mental and physical function before becoming unresponsive to the world, usually passing away at no more than 5 years of age. The disease has shown to mainly affect those of Eastern European Jewish origins.

Down Syndrome: (Not Downs Syndrome) the most frequent cause of mild to moderate mental disability and associated health issues, it affects 1 in 800 Americans across all racial and economic backgrounds. This is caused by an error in cell division resulting in three chromosome 21 (also called trisomy 21).

Environmental factors Environmental factors, also called teratogens, are caused by changes to the prenatal environment. Rubella is a mild disease causing a rash, like a less severe chickenpox. Approximately 25% of mothers who develop up in their first trimester have babies with birth defects including vision and hearing problems, heart problems, mental disability, and rarely cerebral palsy. Miscarriage of the fetus is also common.

Fetal Alcohol Syndrome Drinking alcohol when pregnant is risky. Drinking too much can lead to a child having Fetal Alcohol Syndrome, which is considered to be one of the leading causes of mental disability in the world.

Zika Virus A recent discovery, Zika Virus is a disease transmitted by mosquitoes that is mild for adults, often having either no symptoms or a mild rash and fever. However, women who are pregnant when infected by the virus can have children with microcephaly, which literally translates to “small head”. People with microcephaly can have mental disabilities as well as poor motor control and other issues.

Reflexes and Developments of Newborns Some Reflexes available at birth are: Grasping reflex: Holds a finger or other object firmly Rooting reflex: Turns head when touched on cheek Gag reflex: Clears the throat Startle reflex: Flings out the arms, fans the fingers, and arches the back in response to a sudden noise Sucking reflex: Sucks objects placed in mouth Babinski reflex: Curls toes when outer edge of sole of foot is stroked

Motor Development Milestones (average): 1 month: Rolls over & Grasps rattle 6 months: Sits without support 7 months: Stands holding on 8 months: Grasps with thumb and finger

Motor Development Milestones, continued 11 months: Stands well alone 12 months: Walks well alone 15 months: Builds tower of two cubes 17 months: Walks up steps 24 months: Jumps in place

Cultural Influences Culture has a big impact on the development of a child as well, in many different forms. These can range from whether the baby sleeps with their parents or in a crib, bottle vs breastfeeding, and when they first eat solid food. Poverty and availability of health services vary from country to country, and play a big part of child mortality rates. https://www.cia.gov/library/publications/the-world- factbook/rankorder/2091rank.html