Term
Prenatal Development and
Childbirth |
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Definition
• Prenatal Growth and Development
• Prenatal Environmental Influences
• Childbirth
• The Evolving Family |
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Term
| Prenatal Growth and Development |
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Definition
• Prenatal development is divided into three
periods:
– Germinal: 0 to 2 weeks
• Begins with conception
– Embryonic: 2 to 8 weeks
– Fetal: 9 to 38 weeks
• Ovulation occurs about 2 weeks after start of
menstrual period.
– The ovum (egg) travels through fallopian tubes, where fertilization may take place.
– If fertilization takes place, a zygote results. |
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Term
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Definition
• Time of extremely active cell vision
• Toward end of first week after conception, cells have developed into a blastula, ball of cells around a fluidfilled center
• Cells begin to differentiate to form supportive structures.
• Twins may develop during the first few divisions of the zygote.
– Monozygotic (identical) twins develop when two identical cells separate and develop into two embryos.
– Dizygotic (fraternal) twins develop when two eggs (ova) are released simultaneously and each unites with a different sperm. |
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Term
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Definition
• Beings when implantation is complete.
• Some cells form the embryonic disc, from
which the child will develop.
• Other cells will form supportive structures
differentiated into the
– placenta
– umbilical cord
– amniotic sac (contains amniotic fluid that
helps cushion the baby) |
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Term
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Definition
• Develops into three distinct layers
– Ectoderm: outer layer
• Will become skin, sense organs, brain, nervous
system
– Mesoderm: middle layer
• Will become muscles, blood, excretory system
– Endoderm: inner layer
• Will become digestive system, lungs, thyroid,
thymus, and other organs |
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Term
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Definition
• During the second month, most major
body structures develop, except the brain.
• Spontaneous abortions (miscarriages)
occur primarily during first trimester,
usually by 12 or 13 weeks.
– Often caused by genetic defects or
unsuccessful implantation
– Maternal age, health, nutrition, and exposure
to toxic substances, are also risk factors. |
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Term
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Definition
• Lasts from the beginning of the third month until
birth
• Organs and systems mature and develop,
especially the brain and nervous system.
• At age 24 weeks, the healthy fetus reaches the
age of viability, meaning it has a 50% chance of
surviving outside the womb if given high-quality
intensive care.
• Half of surviving fetuses born at 24 weeks have
serious anomalies. |
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Term
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Definition
• Three general trends characterize early
developmental processes.
– Cephalocaudal trend
• Development advances from the head to the feet.
– Proximodistal trend
• Development proceeds from the middle of the
body outward.
– Gross-to-specific trend
• Responses become more specific as development
advances. |
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Term
| Prrenatal Environmental Influences |
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Definition
• Both genetic defects and environmental
influences during the prenatal period or childbirth
can result in congenital anomalies.
• Maternal age is linked to increased incidence of
congenital anomalies.
– One in 25 mothers over the age of 45 will have a child
with Down syndrome.
– Age may be related to age of the ova, which may
become damaged over time.
– Hormone levels also shift as women age. |
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Term
| Maternal Health and Nutrition |
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Definition
• Maternal malnutrition in pregnancy is
linked to
– higher rates of spontaneous abortion
– premature birth
– stillbirth
– later difficulties in development
• Early and good prenatal care is associated
with having healthy babies. |
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Term
Critical Periods in Prenatal
Development |
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Definition
• A critical period is one during which the
developing child is at the greatest risk for
harm as a result of teratogens.
• Sometimes exposure to a specific
teratogen causes specific harm.
• Or, exposure to certain teratogens may
increase risk of damage. |
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Term
| Teratogens and Their Effects |
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Definition
• Viruses (HIV, rubella, the flu) may cross the placental barrier and affect the baby.
• HIV-infected mothers transmit HIV to their babies in about one fourth of the cases.
• Certain prescription drugs can cause damage.
• Alcohol may cause fetal alcohol affects or fetal alcohol syndrome.
• Smoking may lead to stillbirth, prematurity, spontaneous abortion, low birth weight and cognitive deficits.
• Amphetamine drugs (e.g., cocaine) may damage the nervous system. |
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Term
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Definition
• Childbirth is divided into three stages:
– initial labor
– labor and delivery
– afterbirth
• Childbirth practices vary widely among cultures
and generations.
• Many women prefer natural childbirth today,
though with medical assistance.
• Birthing centers are becoming more common.
• Cesarean section is performed in 26% of U.S.
births. |
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Term
| Technological Innovations |
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Definition
• Allow physicians to detect problems early
in pregnancy:
– Ultrasound
– Amniocentesis
– Chorionic villus sampling (CVS)
– Fetal monitors |
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Term
| Complications in Childbirth |
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Definition
• Breech presentation may require cesarean
section.
• Baby’s general health is evaluated on the 10-
point Apgar Scale.
• Prematurity is associated with
– Low birth weight
• Preterm status or
• Small-for-date
– Difficulty adjusting after birth
– Behavioral problems in childhood |
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Term
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Definition
• Birth is also a psychological and social milestone for the family.
• The transition to parenting is challenging.
• Pregnancy affects mothers emotionally and
psychologically, as well as physically.
• Fathers may feel a greater sense of responsibility and concern about the future.
• The child experiences birth trauma, a stressful
experience.
• Care must be taken not to harm the fontanels on the baby’s skull—they are not fully hardened and baby may be at risk for brain injury if the head is bumped. |
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Term
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Definition
• Average full-term newborn weighs
between 5 pounds, 8 ounces and 9
pounds, 8 ounces
• Is between 19 and 22 inches long
• May have enlarged genitalia
• Upon birth, babies make major
adjustments to their respiration,
circulation, digestion, and temperature
regulation. |
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Term
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Definition
• Babies are born with two types of reflexes.
– Survival
• Breathing, sucking, rooting, sneezing, gagging
– Primitive
• May have had survival value in evolutionary past,
these reflexes disappear during first months of life
• Social and emotional processes of the
infant will lead to development of
attachment. |
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Term
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Definition
• Breast-feeding is good for mother and
baby, and is part of the reciprocity of the
attachment bond formation.
• Infant-caregiver interactions shortly after
birth establish the foundation of the
attachment relationships that will continue
through life. |
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Term
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Definition
• Prenatal development is divided into three 3-
month trimesters—germinal, embryonic, and
fetal.
• Three general trends characterize early
development—cephalocaudal, proximodistal,
and gross-to-specific.
• Genetic defects and environmental influences
(e.g., maternal age, malnutrition, and specific
teratogens) can cause birth defects. |
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Term
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Definition
• Childbirth is divided into three stages—initial
labor, labor and delivery, and afterbirth.
• Childbirth customs vary across cultures.
• Cesarean sections are being increasingly
performed, even when not medically necessary.
• Premature is associated with low birth weight
and early adjustment difficulties.
• A baby’s general health can be evaluated on a
scale called the Apgar Scoring System. |
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Term
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Definition
• Birth marks a dramatic transition for newborns,
who must make major adjustments to their
respiration, circulation, digestion, and
temperature regulations.
• Babies are born with survival reflexes.
• Shortly after birth, babies and caregivers engage
in behaviors that will lead to attachment, the
emotional bond that forms between the infant
and caregiver.
• Attachment forms the foundation for later social
and personality development. |
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