Prenatal Development, Birth, and the Newborn Baby
Prenatal Development begins at conception. Ovum is largest cell in the body, sperm is
one of the smallest.
 Conception occurs when an egg has erupted from the ovary (as it will every 28
days) and is fertilized in the fallopian tubes or womb. Hormones are released to
prepare the lining of the womb for implantation of the zygote. If there are
abnormalities or faulty implantation, zygote will be shed 2 weeks later with
menstrual flow with the mother never knowing she was pregnant. (One of the
criticisms of the IUD as a form of birth control was that it would prevent
implantation, but the woman would conceive and that was considered by some
people to be abortion of a viable baby) Sperm live for 6 days in the woman’s
environment, but the egg only lasts 1 day after entering the fallopian tube. Most
pregnancies occur within 3 days around ovulation.
Periods of development are measured in trimesters, each being 3 months.
First trimester:
 Zygote is the period of fertilized cell multiplying into a blastocyst during the first
2 weeks. The end of this stage is implantation.
o Implantation occurs between 7 and 9 days after fertilization. The outer
membrane becomes the amnion. As many as 30% of zygotes do not
survive, often due to abnormalities.
o Amnion encloses the developing zygote in amniotic fluid which cushions
the baby from trauma.
o Placental and Umbilical cord
 Chorion surrounds the amnion and form fingerlike villi, blood
vessels.
 Placenta is an organ that connects the mother’s and embryo’s
blood system, permitting food and Oxygen to pass through to the
baby, and waste to be carried off. A membrane screens some
toxins but not all.
 Umbilical cord connects the placenta to the baby, containing one
large vein that brings in blood loaded with nutrients and 2 arteries
that remove waste products.
 Embryo period lasts from the 2nd through 8th week, until the bones begin to form.
Cell differentiation is occurring at this point, and we still don’t know what
triggers an ambiguous cell to become a specific type of cell.
o The embryonic disc separates into:
 Ectoderm- becomes the CNS and skin
 Mesoderm- becomes the muscles, skeleton, circulatory system,
internal organs.
 Endoderm- becomes the digestive system, lungs, urinary tract,
glands
o Neural tube development happens as the ectoderm folds over to form a
neural tube, later to become the spinal cord and brain.
o Sense organs develop in the 2nd month- eyes, ears, nose. Arms, legs and
neck and jaw form, as well as internal organs, heart, liver and spleen.
 Fetus period lasts from 2 mo. to birth. There is rapid growth overall- faster than
any other period in life.
o Third month- now the fetus is responsive, showing early behaviors of
sucking, kicking, and a preview of lungs expanding. The gender of the
baby can be detected by ultrasound by the 12th week. Heartbeat can be
detected.
o Second trimester-by 17 – 20 weeks the mother can detect movement.
 Vernix is a cheeselike substance that protects baby’s skin from
chapping from the amniotic fluid.
 Lanugo is a downy hair that holds the vernix to the skin.
 Neural development is occurring, producing more neurons than
you can use in your lifetime. Glial cells support and feed the
neurons develop. By 20 weeks the baby can show responses to
irritation or stimulation. (During a fetoscopy, the light shines in the
baby’s eyes, so they will try to shield their eyes with their arms and
hands. Amazing.
o Third trimester
 Age of viability is the point at which the fetus can first survive if
born. It varies from 22 to 26 weeks. They will need much help to
survive, incubator, help with breathing. Pres. Kennedy’s baby
Patrick would have survived if he had been born today, but in the
1960’s there wasn’t enough technology to overcome his hyaline
membrane disease.
 The brain’s organization is developing to the point that the fetus
shows alertness and sleep states.
 Fetal personality will link to prenatal behavior. Very active babies
before birth are often difficult babies, with irregular schedules.
They can feel pain by 24 weeks and react to sound with body
movements. They show a preference for mom’s voice and after
birth will suck harder to turn on a recording of mom’s voice
(particularly if the baby has been conditioned on mom’s voice
reading a story to the baby before birth – Dr. Seuss)
 Babies will grow a layer of fat in the last month that will aid baby
in regulating body temperature. Also immunities are being
deposited in the baby’s system to protect against illness.
Prenatal Environmental Influences
 Sensitive periods of development relate to the particular time of critical
development of an organ system. If there is an insult during that time,
development may be impacted permanently.
 Teratogens are environmental agents that can cause damage to the developing
fetus. Later in development, exposure to these agents may do little harm. It’s also
possible to suffer later effects of a drug exposure. Baby girls exposed to DES,
given to mothers to minimize miscarriage, had high risks for vaginal cancer and
malformations of the womb in adulthood- a risk not explored in drug testing.
o Drugs, even prescription drugs, can have impacts on development. Any
drug taken by the mother that has a molecule small enough to penetrate
the placental barrier can affect the fetus. Even aspirin can relate to low
birth weight, increased mortality, lower IQ and poorer motor development.
Even caffeine links to low birth weight, miscarriage, withdrawal
symptoms in the baby such as irritability, vomiting.
 Prescription- This was tragically seen with thalidomide, used to
sedate mothers, but producing gross deformities in limbs, ears,
heart, kidneys, & genitals.
 Illegal drugs
 Cocaine produces drug-addicted babies with multiple
problems- prematurity, low birth weight, defects, breathing
problems, death at birth. These babies cry is so shrill that it
affects the caregivers. It may devolve into attachment
problems if the mother can’t care for the infant adequately.
There are affects to the blood vessels and oxygenation of
the baby after a dose, which can permanently affect neural
development. Motor and language functions are affected.
Crack babies have the most serious problems.
Unfortunately these babies’ problems don’t end with birth,
since their mothers are usually unable to adequately care
for them.
 Marijuana relates to low birth weight, prematurity.
 Heroin/ methadone produces addicted babies, less
responsive, with poor motor development.
o Smoking exposes babies to tobacco and produces low birth weight,
miscarriage, impaired breathing, greater mortality risk, cancer later in
childhood. It also puts the mother at increased risk of bleeding. These
babies seem to have shorter attention spans, poorer memories, lower IQ
scores and more behavior problems later. Nicotine constricts blood
vessels, so nutrients and oxygen are in shorter supply to the baby. Also it
increases carbon monoxide in the baby’s blood. That affects CNS
development. Even passive smoke exposure affects the baby.
o Alcohol is the single greatest cause of birth defects and is completely
preventable. The effects on the baby are permanent, even if the baby gets a
rich environment after birth. The brain is permanently affected in structure
and function. The brain simply did not get enough oxygen to develop.
Even one drink per day has affects on fetal development and growth.
 Fetal alcohol syndrome (FAS) is the severe form of the
impairments due to mother’s drinking. It shows as mental
retardation, impaired coordination, attention problems, impaired
memory and language, hyperactivity. There are particular facial
abnormalities and small skull and brain.
 Fetal alcohol effects (FAE) is a milder form yet there are
significant impairments in learning potential.


o Radiation effects were clearly seen after Hiroshima, Chernobyl. A great
many babies miscarried, others were born with underdeveloped brains,
deformities, slow growth patterns. There may be heightened risk to the
baby of childhood cancer, lower IQs, learning and emotional disorders.
o Pollution
 Mercury- effects of exposure are physical deformities, mental
retardation, speech impairments, motor problems.
 Lead – effects are prematurity, low birth weight, brain damage,
physical defects.
 PCBs- low birth weight, discolored skin, deformities of gums,
nails, brain waves, poor cognitive development.
o Infectious diseases
 Rubella – German measles in the mother during sensitive periods
in fetal development results in heart defects, eye cataracts,
deafness, internal abnormalities, mental retardation.
 HIV & AIDS is passed to a fetus 20 – 30% of the time. It causes
weight loss, diarrhea, respiratory illness, brain damage. Most
babies survive only 5 – 8 months once symptoms appear. If the
mother uses AZT, it reduces transmission to the baby 95%.
Unfortunately, in Africa, most clinics have no access to these lifesaving drugs, so babies are born infected and soon die.
 Herpes results in infection of baby during birth, miscarriage, low
birth weight, malformations, mental retardation.
 Toxoplasmosis is contracted from cat feces or undercooked meat.
If the baby is exposed during a critical period, it can cause brain
and eye damage.
Prenatal Environment and later health
o Low birth weight and CVD- infant’s poor weight gain results in
cardiovascular disease in adulthood. Poor nutrition can also result in
diabetes by affecting pancreas function. Stress hormones from the mother
may also retard fetal growth, increase blood pressure and produce
hypoglycemia. Low weight gain often is compensated by later weight gain
that predisposes to diabetes.
o High birth weight and breast cancer – high birth weight in babies
relates to later breast cancer. It seems to be due to high levels of estrogen
during pregnancy which affects breast tissue development.
o Prevention occurs as we care for our health in a thoughtful way as we
have control over eating, exercise, preventive medicine.
Other maternal factors
o Nutrition- during a healthy pregnancy, mom will gain about 25-30
pounds. If the baby is malnourished, there is serious damage to the CNS,
seen in lower brain weight. It will also affect other organ system
development, especially the immune system, resulting in frequent illness.
Lack of folic acid particularly affects neural tube formation, showing up as
anencephaly or spina bifida.
o Stress relates to miscarriage, prematurity, low birth weight and baby
irritability, respiratory illness, GI tract problems. It also relates to cleft
palate and pyloric stenosis which affects nutritional intake. Stress
hormones shift blood flow from the body to the brain and reduces
oxygenation. Stress also affects immunity, increasing illness.
o Rh Factor Incompatibility occurs when the mother is Rh-negative but
the baby is Rh-positive. The mother’s body will form antibodies to fight
the foreign blood protein being produced by the baby. It can reduce
oxygenation to the baby. First babies are usually not affected, but the risk
occurs to later pregnancies. There is a vaccine given to the mother of a
positive baby to prevent buildup of antibodies. Blood transfusions may be
necessary after birth.
o Maternal age/ previous births can affect ability to get pregnant or
chances of having a baby with chromosomal defects (Downs syndrome)
but other complications are no more prevalent in older mothers.
Prenatal health care is essential to make sure the mother is not developing serious
problems, such as toxemia where the blood pressure increases, with swelling in the
extremities. Mother may need to go to bed to avoid serious effects. Many women delay
seeing a doctor,, particularly younger mothers or impoverished mothers. Their babies
have more problems as a result.
Childbirth
 Stages of childbirth
o Dilation and effacement of the cervix- longest stage of labor, lasting 12
to 14 hours, as the contractions of the uterus stretch open the cervix.
o Birth only lasts 20 – 50 minutes as the mother pushes the baby out.
o Delivery of placenta occurs with a few final pushes, as it separates from
the wall of the uterus, its job done.
 Baby’s adaptation to birth is facilitated by the baby’s own stress hormones.
They send a rich supply of blood to the brain and heart. They also help the baby to
breathe better as the lungs absorb extra fluid, and expand the bronchial tubes.
They also arouse the infant into alertness.
 Newborn’s appearance: about 20 in. long, 7.5 pounds, head large in comparison
to body. Often their heads are misshapen from time in the birth canal. But they
have round faces, fat cheeks and big eyes, which make adults bond and cuddle
them.
 Apgar scale ranges from 0 to 2 on each measure, giving an overall score of up to
10 points. A baby who scores less than 7 is in distress; less than 4, is in serious
trouble and needs emergency attention.
o Heart rate
o Respiratory effort
o Reflexes
o Muscle tone
o Color
Approaches of Childbirth have changed a lot in Western society, as medical science has
improved and childbirth is considered a medical condition, not a natural part of life to be
dealt with in the home. Today birth centers allow medical intervention as necessary, but
family members can be present for the birth. Some women still birth at home.
 Natural, prepared childbirth is a variety of techniques that help reduce pain and
make childbirth rewarding and involving of other family members.
o Classes about labor and delivery to reduce anxiety.
o Relaxation and breathing training counteract pain.
o Labor coach is often the father, who helps mom to relax, breathe, offers
massage and emotional support. The father feels more involved and it aids
bonding for the dad.
 Home delivery
o Nurse-midwives have degrees in nursing and training in childbirth. This
allows for a more personal birth environment, but the baby could be at risk
if it has problems.
 Medical interventions may be necessary if the baby is in distress during birth. A
baby trapped too long in the birth canal can develop cerebral palsy due to lack of
oxygen.
o Anoxia puts babies at risk for neural damage that can be permanent.
o Breech position is when the baby is turned feet first. The cord may be
wrapped around the baby’s neck and constrict blood/ oxygen flow. Often a
cesarean section is the choice in this condition.
o Fetal monitoring tracks the baby’s heart rate during labor. If the baby
shows distress, surgery may be required. This monitor can be on the
mother’s stomach, or threaded through the birth canal and pasted on the
baby’s head.
o Labor and delivery medication is used in 80+% of births. Analgesics
reduce pain. Anesthetics are stronger pain killers that block pain. Spinal
blocks can completely numb the body below the waist. These drugs can
weaken contractions and interfere with the mother pushing. They may
leave the baby druggy, without the interest or ability to suck for awhile.
o Cesarean Delivery is a surgical birth through the abdomen. 20% of births
in US and Canada are this way. It is used for Rh incompatibility,
separation of the placenta, maternal illness such as herpes2, breech births.
Recovery is longer for the mother, and the baby may be less responsive.
Preterm and Low-Birth-Weight babies are less than 5.5 pounds or before 38 weeks
gestation. 1/14 babies in US is born underweight. The poor, the teen mothers have the
greatest risks.
 Preterm babies are born weeks before their due date. They may or may not be
underweight.
 Small for Date babies are below normal weight. Some may be full term, others
are preterm. These babies have more serious problems, higher mortality, more
chance of brain damage, lower IQ scores later, problems with attention.


Consequences in caregiving for preterm babies are that they are treated more
delicately, held less often, less closely & are at higher risk for abuse, as parents
may be frustrated by the baby’s unresponsiveness.
Interventions for preterm babies
o Isolette is a temperature-controlled bed that filters air to enable their lungs
to function. These babies are at risk for respiratory distress syndrome
because their lungs are poorly developed.
o Special infant stimulation such as a hammock, waterbed, music, or tapes
of the mother’s voice promote weight gain and greater alertness. Massage
also increases weight gain and advanced IQ and motor function.
Kangaroo care is carrying the baby between the mother’s breasts to
regulate temperature and stimulate oxygenation and sleep.
o Training parents in caregiving allows the parents to feel more confident
in caring for their babies. With coaching, even impoverished or
uneducated parents can do a good job enabling their babies to develop as
much as possible. Most programs stop the interventions early in life,
though, and studies are finding these children need interventions to sustain
development past age 3, even into the school years.
Infant mortality assesses the health of a nation’s children. It assesses deaths in the first
year of life per 1,000 live births. In spite of technological advances, the US is only 24th in
infant morality in the world. African-American babies are at greatest risk in the US
(twice as likely to die in the first year as white babies in US)
Neonatal mortality is the rate of death within the first month of life (67% of
infant death rate). It may be due to serious physical defects at birth, or low birth weight.
In countries with lower mortality rates, the parents have assistance in staying home after
birth. Studies have shown that 6 weeks of paid leave is not enough to enable healthy
development. 12 weeks is associated with better outcomes. Single mothers have the least
chance of that kind of support.
SIDS (Sudden Infant Death Syndrome) is the unexpected (and often unexplained)
death, often during the night, of an infant under 1 year of age. SIDS is the leading cause
of infant mortality between 1 and 12 months of age. These babies often have problems at
birth, low birth weight, prematurity, low Apgar scores, abnormal heart rate or respiration.
The hypothesis is that there is impaired brain function that does not respond when
survival is threatened, such as if the baby stops breathing. This usually alerts the brain
when oxygen levels drop to a certain point in the blood, to gasp and breathe. These are
reflexive responses, yet they don’t develop effectively in these babies. These babies
simply give in to oxygen deprivation and die during the night, without a whimper.
Related factors: maternal smoking, prenatal abuse of drugs such as opiates or barbiturates
(increases SIDS risks 10 times), sleeping on their stomachs, wrapped up in too many
blankets, so they stay too warm. These factors contribute to sleep deprivation, so when
babies rebound and sleep deeply, their airways may collapse and the baby won’t arouse at
loss of air. Babies sleeping on soft bedding inhale their own CO2 and die from lack of
oxygen, too. Parents often suffer unmollified grief, feeling they should have done
something, yet they didn’t know what to do.
Birth complications can result in later death, but quality of home environment makes a
difference here. Even moderately stressed children, given high quality home
environments do well on IQ and adjustment scales later. Babies who were pretty and had
positive personalities also received more positive responses from adults that enabled
better development. There are bidirectional impacts on baby and parents from each
person’s personality and responsiveness.
Newborn baby’s capacities
 Newborn reflexes are inborn, automatic responses to a particular stimulation.
Some reflexes have survival value: Rooting reflex, sucking. Other reflexes form
the basis of later functions: Stepping reflex, swimming reflex, palmar grasp,
tonic neck reflex. Sucking also promotes interaction with parents or selfsoothing. Most reflexes fall out between 2 and 4 mo., as voluntary responses
develop in accord with more controlled brain function.
 Newborn States of Arousal are degrees of sleep and wakefulness.
o Sleep is the most common state of the newborn, 16+ hours a day.
 Rapid eye-movement sleep (REM) associates with a brain wave
rhythm that is much like wakefulness, with twitches and moves.
This seems to be the brain’s way of stimulating itself when the
baby is sleeping so much. This aids development of the CNS.
Babies spend much more time in REM sleep than at any other time
of life. The rapid eye movements aid the health of the eye,
circulating moisture and oxygenating the eye.
 Non-rapid eye-movement sleep (NREM) is almost motionless
sleep with deep, slow brain waves and slowed heart rate.
o Crying is the baby’s only communication method at birth, yet it is very
effective in stimulating the responses of others. Everyone is bothered by a
crying baby, whether it is yours or not. Parents come to recognize and
discriminate their baby’s cry from others. Most cries are to alert to
physical needs, hunger, temperature changes, noise, pain, discomfort.
Babies will also emit an empathy cry when they hear other babies crying!
We are born with the potential for empathy for others, but life and abuse
can obliterate it over time.
o Soothing
 Pick up, rock or walk baby.
 Swaddle the baby in a blanket or hold him close to your body.
 Offer a pacifier.
 Stroll or car ride.
 Massage.
 Make rhythmic sounds. (Ssh, ssh, sh!)
 Let baby cry for short periods to recover your nerves.
o Abnormal crying is seen in brain-damaged babies. This cry is shrill and
piercing and often triggers negative responses in caregivers. This is
another reason these babies are often abused.
o Colic is a persistent crying that often occurs late in the afternoon, perhaps
due to poor brain regulation of arousal cycles, or poor digestion.
Sensory capacities
 Touch stimulates physical development, but also emotional development. Babies
are very sensitive to touch and they do feel pain. Now we give local anesthetics to
babies being circumcised, but in the past it was thought they didn’t feel much, so
they didn’t use anesthetic. Without relief from pain, babies develop a heightened
reaction to pain or distress.
 Taste and smell – babies like sweet tastes (breast milk is very sweet) and they
turn up their nose and react to bitter tastes. Taste preferences may be shaped by
the diet of the mother. Odor preferences are innate and they show a preference for
mother’s smell.
 Hearing is developed before birth, as babies react to loud noises by jumping in
the womb. They prefer complex sounds, voices, etc. They can discriminate the
distinct sounds of all the languages of the world, but quickly come to respond to
the sounds of the native language and lose discrimination of other sounds.
Because babies respond better to more high-pitched sounds, adults take on a
certain “baby language” which is sing song and rises at the end of the sentence.
 Vision is least developed at birth so visual acuity (fine discrimination) is limited,
but babies can see about 8 in. away and can track moving objects. Color vision is
limited, so many newborn mobiles are in black and white.
Neonatal Behavioral Assessment Scale examines the baby’s reflexes, arousal states,
responsiveness to environmental stimuli. Asian and Native-American babies seem to be
less irritable than Caucasian babies, possibly because mothers in those groups respond
with soothing and nursing more quickly, carrying their babies in wraps about their
bodies, which is soothing and stimulating to a baby. Changes in scores in the first weeks
reflect parenting practices and recovery from stress of birth.