Presentation on theme: "Prenatal Development and Birth"— Presentation transcript:
1 Prenatal Development and Birth Part IChapter FourPrenatal Development and BirthFrom Zygote to NewbornRisk ReductionThe Birth ProcessPrepared by Madeleine Lacefield Tattoon, M.A.
2 Prenatal Development and Birth The majority of newborns are male (52%), and more are Chinese (30%)… yet every baby is unique… every area of development is directly relevant to the 150 million babies born in the world every year… there are generalities and variation… but expect to be awed by the miracle of birth.
3 From Zygote to NewbornPrenatal development is divided into three main periodsgerminal Period (0-2 weeks)embryonic Period (3-8 weeks)fetal Period (9 weeks-birth)
4 From Zygote to Newborn blastocyst placenta Implantation Germinal: The First 14 DaysConception occurs in fallopian tubesCell differentiation and multiplication42% of conceptions successfully implant in uterusblastocystwhen cells take on distinct characteristics and gravitate toward particular positions, the entire cell mass (still very fragile and tiny)placentathe organ that surrounds the developing embryo and fetus, sustaining life via the umbilical cord…attached to the wall of the uterusImplantationthe process, beginning about 10 days after conception, which the developing organism burrows into the placenta that lines the uterus, where it can be nourished and protected as it continues to develop.
5 From Zygote to Newborn embryonic period (3-8 weeks) Embryo: from the third through the eighth weekembryonic period (3-8 weeks)major organs developat eight weeks, organism is less than 2˝ long
6 From Zygote to Newborn Fetus: From the Ninth Week Until Birth Fetal Period (9 weeks-birth)Sex organs developBrain development is significantAge of viability occurs around 22 weeksfetusa developing organism from the ninth week after conception until birth
7 From Zygote to Newborn The Third Month the fetus has all its body partsweighs approximately 3 ounces, about 3 inches longgrowth is rapidfetus is too small survive outside of the womb
8 From Zygote to Newborn The Middle Three Months: Preparing to Survive in the fourth, fifth and sixth months the heartbeat becomes strongerthe cardiovascular system more activethe brain increases about six times in sizeage of viabilitytwenty-two weeks after conception a fetus can survive outside the mother’s uterus if specialized medical care is available
9 From Zygote to NewbornThe Final Three Months: From Viability to Full TermViabilitylife outside the womb is possibleborn in the seventh month requires intensive hospital care and life-support systemsdifference between preterm and newborn is the maturation of neurological, respiratory, cardiovascular systems
10 Risk Reductiontoxins, illnesses and experiences can harm a developing person before birthteratologya science of risk analysis, the study of birth defectsteratogensAgents and conditions that can harm the prenatal brain, impairing the future child’s intellectual and emotional functioningbehavioral teratogens
11 Risk Reduction Determining Risk risk analysis the science of weighting the potential effects of a particular event, substance, or experience to determine the likelihood of harmTiming of Exposurecritical periodIn prenatal development, the time when a particular organ or other body part of the embryo or fetus is most susceptible to damage by teratogens
12 Risk Reduction Amount of Exposure Threshold effect Interaction effect a situation in which a certain teratogen is relatively harmless in small doses but becomes harmful once exposure reaches a certain level (the threshold)Interaction effectthe result of a combination of teratogens. Sometimes risk is greatly magnified when an embryo or fetus is exposed to more than one teratogen at the same time
13 Risk ReductionProtective MeasuresBenefits of Prenatal Care
14 The Birth Process The Newborn’s First Minutes Apgar scale a quick assessment of a newborn’s body functioning.colorheart ratereflexesmuscle tonerespiratory effort
15 The Birth Process Variations medical Intervention birth complications cesarean sectionfetus is removed through incisions in the mother’s abdomen and uterusbirth complicationsincludes anything in the newborn, the mother, or the birth process itself that requires special medical attentionanoxiaa lack of oxygen that, if prolonged during birth, can cause brain damage or death to the baby
16 The Birth Process Low Birthweight (LBW) the average weight of a newborn is 7½ lbs.LBW is considered less than 5½ lbs.preterm is less than 35 weekslifestyle choicese.g., cigarette smoking accounts for 25% of LBW births worldwide!maternal malnutritionmultiple birthsprescription drugsunknown causes
17 The Birth Process Social Support Postpartum Depression Mother, Father, and a Good StartHelp from fathersparental alliance – cooperation between a mother and a father based on their mutual communication to their children… the parents agree to support each other in their shared parental rolesPostpartum Depression8-15% of women experience postpartum depression, a sense of inadequacy and sadness after birth.includes irritability, sleep and eating disruptions, sadness, feeling overwhelmed and inadequate as a mom, no interest or overly worried about baby.