Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. 1) First Stage of Prenatal Development: Germinal Stage – Conception to implantation – Approximately 2 weeks Timeline – Cell division or mitosis begins 24 hours post fertilization – 2-3 days to reach uterus cells = blastocycst – Implantation fully complete after 2 weeks Thousands of cells Cell differentiation begins

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. 2) The 2 nd Stage: The Embryonic Stage – Implantation to 8 weeks – Major organs and body systems develop Amnio – Membrane which grows over embryo and fills with amniotic fluid – Protects embryo Chorion – Membrane that grows around embryo and becomes the placenta – After 1 mo. of development Petit Format/Photo Researchers

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Placenta – The structure through which nutrients and waste products are exchanged Umbilical cord – The lifeline of the embryo, connecting it to the placenta – Consists of two arteries and one vein During embryonic period, all major systems form Thus, this is a time of great vulnerability

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Developmental Principles Cephalocaudal development – The principle that growth occurs from the head downward Proximodistal development – The principle that body parts closer to the central axis of the body develop first

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Stage 3: The Fetal Stage 8 weeks to Birth Marked by growth and elaboration of structures developed earlier Quickening – Fetal movements during pregnancy felt by the mother Petit Format/Photo Researchers

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. The Fetal Stage Rapid rate of growth 3 rd month of gestation – Sexual differentiation occurs – Male genital development triggered by testosterone release 5 th month – Cells of the brain have migrated and formed connections with other brain cells – Now can communicate with each other and control some body functions – Simple reflex actions appear

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. The Fetal Stage Age of viability – Age at which postnatal survival is likely – 7 months gestation (22 weeks) Newborn – average is pounds – and 20 inches long

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Environmental Influences Developing fetuses are protected by – Amniotic fluid – Placental barrier Teratogens – Agents that cross the placental barrier and adversely affect development – Diseases, Drugs, Environmental Hazards

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Factors Affecting Teratogenic Influence Time of exposure – Teratogens exert their effects on currently developing systems Amount of exposure – The longer or greater the exposure, the worse the effect Fetal characteristics – Individual differences influence the strength of effects

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Maternal Age Advanced maternal age is increasingly common Risks of increased age – Down syndrome – High blood pressure – Gestational diabetes – Cardiovascular disease – Miscarriage

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Maternal Stress Stress causes changes in mom’s blood chemistry. Pregnant women who are highly stressed are at increased risk of: – Miscarriage – Complicated deliveries – Birthing prematurely

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Parity – The number and spacing of children a woman bears Body takes 4 years to return to prepregnancy condition – Infants born before recovery may be disadvantaged Later-born children have – A richer blood supply – Fewer birth defects and complications – Quicker deliveries

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Protective Factors 1) Nutrition Pregnant women – Need about 300 extra calories/day – Need increased levels of iron, protein, folic acid, calcium and phosphorus Ideal weight gain is about 30 pounds Birth defects – Women who do not have adequate folate are at risk of neural tube defects Anencephaly Spina bifida – Half of neural tube defects in the U.S. are caused by inadequate folate intake

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. 2) Exercise – Provides pregnant women with more energy – Builds bones and muscles – Generally improves health – May improve women’s ability to cope with childbirth pain 3) Prenatal Care – Regular prenatal care is associated with lower rates of birth complications – Many women do not receive adequate prenatal care – Pre-natal testing

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. 4) Social Support Having social support helps a woman – Manage stress – Deal with physical demands and complications during pregnancy – Benefits of having a partner – Correlation between mother and father’s stress © Royalty-Free, C Squared Studios/Getty Images

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. The Birth Process gestation is from weeks Lightening (2-3 weeks before delivery) – sensation that occurs when fetus drops into the pelvic cavity in preparation for birth what triggers labor? – fetal release of steroids from adrenal glands – maternal release of prostoglandins or oxytocin Stages of the Birth Process: 1.Dilation of Cervix 2.Expulsion of Fetus 3.Expulsion of Placenta

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Normal Uncomplicated Birth 17

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. What women are at risk for complications? Adolescent girls Older women, especially primiparous mothers over 35 Women with certain diseases or conditions (e.g., diabetes, obesity, malnutrition) Women carrying multiple babies

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Birth Complications: Cesarean Sections Procedure by which the fetus is delivered through an incision in the mother’s abdomen Used – When delays in labor endanger the baby – When the baby is in a breech or transverse position – Unfavorable shape of pelvis – Placenta previa or placenta abrupto – Eclampsa – Prolonged labor – diabetes

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Birth Complications 20

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Cesarean Sections There has been a sharp rise in c-sections in the past three decades Many factors account for the rise While c-sections can be effective, they carry increased risks

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Induced Labor Sometimes allowing a pregnancy to continue is dangerous for mother or child Labor can be induced – Pitocin used to stimulate contractions Induction rates have increased

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. APGAR scale A quick method of diagnosing potential problems in newborns 5 vital signs are assessed – Respiration – Reflex responsiveness – Muscle tone – Respiration – Color – Heart rate

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. Newborns at Risk Preterm – A.k.a. premature – Babies born prior to 37 weeks gestation Small for Gestational Age – Babies born after 37 weeks gestation but weighing less than 5 pounds Both are high risk Low Birth Weight, Very Low Birth Weight, Extremely low Birth Weight Rates vary by racial/ethnic group

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Consequences Many children develop normally and are healthy – Plasticity of nervous system – Resilience Potential issues include – Subnormal growth – Mental retardation – Blindness – Deafness – Cerebral palsy – Health problems

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. The Mother’s Perspective Baby blues – Common experience of intense emotionality following childbirth – Contributions Biological changes Fatigue Loss of attention Increased demands at home Sense of anticlimax Feelings of inadequacy

Copyright © Houghton Mifflin Harcourt Publishing Company. All rights reserved. The Mother’s Perspective Postpartum Depression – An episode of clinical depression triggered by childbirth – Causes? Biological changes Stressful life events Delivery complications Sleep deprivation – Often requires medical treatment Postpartum Psychosis