Stages of Prenatal Development
Stages of Prenatal
Conception occurs when a sperm cell
penetrates and fertilizes an egg cell
Successful conception depends on
ovaries releasing one healthy egg cell
egg cell migrates most of the way down the
One sperm must penetrate the ovum to form a
About 15 percent of couples are unable to
conceive or carry a pregnancy to term after one
year of unprotected intercourse.
Causes of male infertility involve the quantity or
strength of sperm produced.
Causes of female infertility
involve structural abnormalities
in the Fallopian tubes or uterus
or a failure to ovulate and
release mature eggs.
New technologies are now
available to help overcome
The Germinal Stage (first two weeks)
-The blastocyst is differentiated into three layers: the
ectoderm, the endoderm, and the mesoderm.
-The blastocyst moves down the fallopian tube into
the uterus for implantation.
-The embryonic stage begins with implantation, and
the fully implanted blastocyst is referred to as the
Embryonic Stage (3rd through 8th weeks)
Growth in the embryonic and fetal stages follows a
cephalocaudal (head-to-tail) pattern and a
proximodistal (near-to-far) pattern.
The head, blood vessels, heart, and most vital
organs begin to develop before the arms, legs,
hands, and feet.
Embryonic stage (slide 2)
The placenta forms as an area of the
uterine wall through which oxygen and
nutrients reach the fetus.
The umbilical cord connects the embryo to
the placenta and provides nutrients and
carries away waste products.
The amniotic sac surrounds the embryo
and protects it.
Fetal Stage (9th to birth)
The fetal stage is marked by the development of
the first bone cells. The embryo is now called the fetus.
By the third month, the fetus is able to move its
head, legs, and feet. By the fourth month, the mother may
feel quickening, or fetal movement.
3. The beginning of the seventh month is considered the
age of viability.
At the end of nine months, the fetus weighs on
average 7.5 pounds and is almost 20 inches long.
The experience of pregnancy
1. Physical complaints such as nausea
2. Normal weight gain is about thirty
pounds and is dispersed in organs, baby,
and bodily fluid.
3. Changes in the woman's body bring
Prenatal influences on the child
- Canalization is seen in prenatal development.
-Drugs and other harmful environmental influences
can also canalize development, usually in
-Risk factors can interfere with canalized
processes that lead to the development of
Maternal diet and nutrition
-Poor nutrition leads to specific physical deformities
and increased risk for prematurity and infant
mortality; later nutritional deprivation leads to a
reduced number of brain cells.
- Pregnant women should eat between two hundred
and one thousand calories more per day, adding
mainly carbohydrates and protein.
Prenatal health care (1 of 2)
Adequate early prenatal health care is critical
to infant and maternal health.
There are racial differences in adequacy of
Special programs have been implemented in
communities to help high-risk mothers.
Prenatal health care (2)
1. Prolonged anxiety just before or during
pregnancy increases the likelihood of medical
2. Emotional stress is related to spontaneous
abortion as well as to labor and birthing
The birth episode
After about thirty-eight weeks in the womb, the
baby is considered "full term," or ready for birth.
Fetal presentation refers to the body part
closest to the mother's cervix. There are three
types of presentation: Cephalic (normal), breech,
Stages of labor
1.During the last weeks of pregnancy, it is common for
the mother to experience false labor, or BraxtonHicks contractions.
2.The first stage of labor usually begins with
relatively mild contractions, leading to stronger
contractions and the dilation of the cervix to
accommodate the baby's head (10 centimeters).
Stages of labor
Toward the end of the first stage, which may take from eight to
twenty-four hours, a period of transition begins, and the baby's head
begins to move through the birth canal.
4. The second stage of labor is from complete dilation of the cervix
to birth, lasting about one to one and one-half hours.
5. During the third stage of labor, which lasts only a few minutes,
the afterbirth (consisting of the placenta and umbilical cord) is
Childbirth settings and methods
Traditionally, childbirth was attended by a midwife
and was seen as a natural process. With the advent
of modern technology, births increasingly took
place in medical settings.
This resulted in
decreased mortality rates, but birth was now seen as
a medical event controlled by physicians.
1. Hospital births. Birthing rooms are becoming more popular in
2. Non-hospital settings
a. Freestanding birth centers are non-hospital facilities that
provide family centered maternity care.
b. Birth centers have lower rates of Caesarean sections.
c. Home births are another alternative for pregnancies
predetermined to be low risk.
3. Prepared childbirth. Methods of prepared childbirth help
parents rehearse the sensations of labor.
A.Programs emphasize educational, physical,
and emotional preparation for the birth process
and use of a coach.
B. Women who participate in birthing programs
report favorable effects.
C. Leboyer claimed a gentle birth has benefits
for the child.
Lamaze birth philosophy
Integral to the work of Lamaze International is a fundamental philosophy of
Birth is normal, natural, and healthy.
The experience of birth profoundly affects women and their families.
Women's inner wisdom guides them through birth.
Women's confidence and ability to give birth is either enhanced or diminished
by the care provider and place of birth.
Women have the right to give birth free from routine medical intervention.
Birth can safely take place in birth centers and homes.
Childbirth education empowers women to make informed choices in health
care, to assume responsibility for their health, and to trust their inner wisdom.
Medicinal aids to birth
Despite good psychological preparation, the mother may
experience considerable pain, which can be made bearable
through pain-reducing drugs such as narcotics or other
a. The most common anesthetics are epidural and spinal,
which allow the mother to remain awake and alert during
b. A general or local anesthetic delays the recovery of the
mother as well as the bonding between mother and child.
Pain in childbirth
5. Perceptions of pain during childbirth
a. It is difficult to determine how much discomfort or
distress a laboring woman is in and how to respond
b. There are cultural differences in the perceptions of
Problems during labor and delivery (1 of 3)
Faulty power is the failure of the uterus to contract
strongly enough to make labor progress to an actual
delivery. Induced labor can be stimulated by the hormone
2. A faulty passageway condition occurs when the
placenta develops so close to the cervix that it blocks the
baby's passage down the birth canal during labor. This
condition is called placenta previa.
Problems with Labor and Delivery (2 of 3)
3. A faulty passenger condition occurs when problems exist with
the baby's position or size. Usually babies enter the birth canal
head first, but occasionally one turns in the wrong direction
during contractions. Forceps sometimes are used to remedy the
4. In a Caesarean section, the mother receives a general
anesthetic and the baby is removed surgically. Techniques for
this surgery have improved; however, a common criticism is that
too many Caesareans are performed.
Problems with Labor and Delivery (3 of 3)
To deal with such problems, in most hospitals,
electronic fetal monitoring is used to record
uterine contractions and the fetal heart rate.
Low-birth weight infants
Normal is around 7.5 pounds
Low-birth weight is 5.5
pounds or less
6 or 7 percent of all births in
At risk for developmental,
neurological, and health
More than three
At risk for
Negative Prenatal Influences on the Child
Window of opportunity
concept--critical time of
Teratogen is any substance
or influence that can interfere
with or damage a child’s
Teratogenic Medicinal drugs
Thalidomide is a sedative, also an anti-nausea
drug--but deforms children.
Diethylstilbestrol (DES) was used to prevent
miscarriages but causes damage to reproductive
systems of offspring.
Other potentially harmful prescribed drugs are
accutane, streptomycin, and tetra-cycline.
Teratogenic non-medicinal drugs (1 of 3)
Is stored in fatty tissues of
Placenta is no barrier
Babies are born with psych.
if not physical addiction
An opiate not totally unlike
morphine, but more addictive
Newborn babies of heroin
addicts vomit, tremble, cry,
and have fever, disturbed
sleep, and abnormal cries
Fetal alcohol syndrome
CNS damage, heart defects,
small head, distortion of joints,
and abnormal facial features
Are evident in their inability to
pay attention or maintain
Nicotine and carbon
monoxide interfere with fetal
Smoking is associated with
low birth weight,
spontaneous abortion, higher
infant mortality, and poor
Maternal Diseases (1 of 2)
Rubella, or German measles. Disastrous in first
Syphilis and gonorrhea. Blindness, jaundice,
anemia, pneumonia, skin rash, early death. Silver
nitrate in the eyes.
Genital herpes. (1) Disease of skin and mucous
membranes, or (2) blindness, permanent brain
damage, seizures, and developmental delay.
Maternal diseases (2 of 2)
Cytomegalovirus (CMV). High risk for infants;
jaundice, microcephaly, deafness, and eye
Toxoplasmosis. Parasite from uncooked meat
and cat feces. Low birth weight, enlarged liver
and spleen, microcephaly, anemia, and
calcifications in the brain.
“Babies having babies”-own growth is not complete
Pelvic cradle not ready
Threat to education
Responsibility not yet
Seven to Eight percent
of pregnant women are
beaten by partners; most
more than once
High rate of miscarriage