Prenatal development in developmental psychology

prenatal developmental period

1. Prenatal development Presented by: Rabia Javed Iqbal

2. Stages of Pregnancy During a full-term human pregnancy, a fetus is carried in the uterus for a gestation period averaging 280 days from the last menstrual period until birth The 280 days are frequently divided into 10 four-week lunar months of 28 days each , which equal slightly more than nine calendar months. Pregnancies are also often divided into trimesters, periods of three calendar months (13 weeks).

3. Forming A New Life: Prenatal Period Conception or fertilization The process by which sperm and ovum combine to create a single cell called a zygote. Gestation Period of development between conception and birth. Approximately 9 months or 266-day period

4. Characteristics of Prenatal Period Hereditary endowment of an individual is fixed. Favorable conditions in the mother’s body is very important. Sex of the individual is fixed at the time of conception Proportionately greater growth & development during this period. This period is a time of many hazards both physical & psychological This period is the time when significant people form attitudes toward the newly created individual

5. Importance of conception Hereditary Endowment Sex Number of Offspring Ordinal Position

6. Hereditary Endowment Effects: Limits where an individual can go because of inherited mental & physical traits Entirely a matter of chance Patterns of genetic transmission Dominant and recessive inheritance Genotypes and phenotypes Chromosomal abnormalities

7. Autosomes = 23 pairs Sex chromosomes Chromosomes are rod-shaped structures that contain biological blueprints, or genes. A male zygote (XY) is the product of the fusion of an egg with a sperm carrying a Y chromosome; a female zygote (XX) is the product of the fusion of an egg with a sperm carrying an X chromosome. The X chromosome provides valuable genetic material essential to life and health. The Y chromosome is smaller than the X and carries little more than directions for producing a male.

8. Multiple pregnancy A multiple pregnancy occurs if two or more eggs are fertilized, or a single fertilized egg divides into two or more zygotes. Two embryos from a single egg develop into identical twins Three embryos develop into identical triplets. Two separate eggs fertilized by two sperm develop into fraternal twins.

9. Dominant inheritance: When a person is heterozygous for a particular trait, the dominant alleles governs. Recessive inheritance: The expression of a recessive trait occurs when a person receives the recessive allele from both parents

10. Phenotype: The array of observable characteristics through which your genotype is expressed. Genotype: The underlying genetic makeup.

11. Sex-linked inheritance certain recessive traits linked to genes on the sex chromosomes are transmitted differently to male & female children, Mother is the carrier. Example: Duchene muscular dystrophy Red-green color blindness Hemophilia

12. Implantation Fertilization – The union of a male sperm cell and a female egg cell in the fallopian tube (conception) Resulting cell is called a zygote Within a day after the zygote forms, it begins dividing as it travels down the fallopian tube. By the time it reaches the uterus, the zygote has divided many times to form a cluster of cells with a hollow space as the center.

13. Within a few days, the zygote attaches to the uterine wall (implantation) The cluster of cells that develop between the third and eighth weeks of pregnancy – Embryo (usually the 5th week) After about the eighth week, this developing groups of cells is called Fetus

14. Embryonic Growth As the embryo grows, its cells continue to divide, forming three tissue layers: Respiratory and digestive system Muscles, bones, blood vessels and skin Nervous system, sense organs and mouth

15. During this time, two important structures form outside the embryo: Amniotic sac: a thin, fluid-filled membrane that surrounds and protects the developing embryo. It also insulates embryo from temperature changes. Umbilical cord: ropelike structure that connects the embryo and the mother’s placenta. The placenta is a thick, blood-rich tissue that lines the walls of the uterus during pregnancy and nourishes the embryo.

16. Blood supply of the mother and developing embryo are kept separate, materials still diffuse from one blood supply to the other through the umbilical cord. Harmful substances such as tobacco, alcohol or other drugs can cross the placenta and harm the embryo

17. 0-14 weeks – First Trimester 15-28 weeks – Second Trimester 28-40 weeks (birth) – Third Trimester

18. Dilation The final stage of pregnancy in which the uterus contracts and pushes the baby out of the mother’s body Stage 1: Dilation Stage 2: Passage through birth canal Breech birth – baby enters the birth canal feet or buttocks first Stage 3: Afterbirth (placenta)

19. Proper Nutrition During Pregnancy Calcium – helps build strong bones and teeth, as well as nerves and muscles. Protein – helps form muscle and most other tissue. Iron – makes red blood cells and supplies oxygen to cells. Vitamin A – aids in cell and bone growth and eye development. Vitamin B complex – aids in forming nervous system. Folic acid – critical part of spinal fluid and helps close the tube that contains the central nervous system.

20. Proper Nutrition During Pregnancy Weight gain is expected (25-35 lbs.) Most only need an additional 300 calories per day, though. Excess weight can be a health risk for mother and baby Caffeine can increase risk of birth defects or low birth rate Physical activity can be beneficial

21. Tobacco and Pregnancy It is estimated that smoking accounts for: 30% of low birth weight 14% of premature births 10% of infant deaths May also affect the growth, mental development and behavior of child until 11 years old

22. Alcohol and Pregnancy Alcohol consumed during pregnancy quickly passes through the umbilical cord to the fetus. The fetus breaks down alcohol much more slowly than an adult does, so the alcohol level in the fetus’s blood can be higher than that of the mother and remain higher for a longer period of time.

23. Fetal Alcohol Syndrome A group of alcohol-related birth defects that includes both physical and mental problems Mental retardation Learning disabilities Serious behavior problems Slowed growth Physical deformities including a small skull, abnormal facial features, and heart defects

24. Medicines, Other Drugs, and Pregnancy Using drugs can have serious consequences Birth defects Premature labor Miscarriage Even OTC medicines should only be taken with the approval of the doctor A baby can be born addicted to the drugs the mother used during pregnancy. The infant will suffer withdrawal symptoms: hypersensitive and irritable and may cry for hours tremble and jerk May not bond with parents

25. Complications During Pregnancy Miscarriage – the spontaneous expulsion of a fetus that occurs before the 20th week Stillbirth – dead fetus expelled from the body after the 20th week Ectopic Pregnancy – zygote implants in the fallopian tube, abdomen, the ovary or the cervix. Zygote can’t pass to the uterus STD could be a reason

26. Sterility Inability to reproduce Males: may be due to stress, drug use or disease Females: may be due to blocked fallopian tubes or severe scarring from STIs.