Human Growth and Development - Section 1, Lesson 1 (prenatal development)

What defines the prenatal age period

Starts at conception, continues through implantation in the uterine wall by the embryo, and ends at birth

What defines the Infancy and Toddlerhood age period

Starts at birth and continues to two years of age

Starts at two years of age until six years of age

What defines the early childhood age period

Starts at two years of age until six years of age

What defines the middle and late childhood age period

Starts at six years of age and continues until the onset of puberty

What defines the age period of adolescence?

Starts at the onset of puberty, ends at the age of 18

What defines the age period emerging adulthood?

ages 18 to 25

What defines the age period early adulthood?

ages 25 to 40-45

What defines the age period middle adulthood?

ages 40-45 to 65

What defines the age period late adulthood?

65 onward

What are characteristics of prenatal development?

Conception occurs and development begins. All major structures of the body form. Health of the mother is the primary concern. Nutrition, teratogens (drugs, alcohol, chemicals, infections, etc) or environmental factors leading to defects also of concern.

What are characteristics of infancy and toddlerhood?

Drastic changes in development.

How long does the germinal phase in conception last?

14 days, from conception to implantation.

how do other sperm not meet the egg once the egg is fertilized?

the outside of the egg hardens

What is a fertilized egg cell (contains both parents information), called

a zygote

What does the zygote become after 5 days of mitosis (now has 100 cells)?

a blastocyst

A blastocyst has both inner and outer cell layers. What do each of these become?

inner embryonic disk becomes the embryo, outertrophoblast becomes support system to nourish.

What percentage of blastocysts do not implant?

50-75%

How many zygotes survive past the first 2 weeks of mitosis?

less than 50%

What are reasons that a zygote may fail?

too little or damaged genetic info, egg and sperm do not combine properly and genetic material does not combine, zygote does not replicate, blastocyte does not implant.

What is a zygote?

a fertilized ovum

what is mitosis?

cell division producing two daughter cells with the same number of chromosomes as the parent cell

What is a blastocyst in mammals?

embryo prior to implantation

when does implantation occur?

by the 3rd week of conception

Embryonic period: What is a blastocyst called upon implantation?

an embryo

Embryonic period: What happens after implantation?

blood vessels grow, which forms the placenta

Embryonic period: What is the placenta for during the pregnancy

providing nourishment and oxygen to embryo during pregnancy

Embryonic period: growth during prenatal development occurs in how many directions?

cephalocaudal (head to tail), and proximodistal (middle to outer)

Embryonic period: what do the directions of growth (cephalocaudal and proximodistal) mean for how an embryo develops?

structures nearest to the head or nearest to the midline are first to develop

Embryonic period: by what week of pregnancy does the heart precursor begin to beat?

week 4

Embryonic period: by what week does an embryo’s head develop

week 4

Embryonic period: by what week does an embryo’s gills and tail begin to disappear

week 4

Embryonic period: What is the size of an embryo at the end of 8 weeks?

length is 1 inch and weighs about 8g. Can move and respond to touch

Embryonic period: Why would an embryo fail during this period?

Usually due to gross chromosomal abnormalities

When is the developing organism most vulnerable to damage if exposed to harmful substance?

Embryonic Period

What is a developing organism called from the 9th week up to birth?

a fetus

By what month does a fetus have all body parts including genitalia?

3rd

What is the size of the fetus in the 3rd month of pregnancy?

3”, 28g

During which months of pregnancy do the fetus’ eyes become more sensitive to light and hearing develops?

4-6

During which month of pregnancy does the respiratory system and reflexes such as hiccuping, sucking, and swallowing, and sleep/wake cycles develop?

5

When is the age of viability?

24 weeks

When have the majority of (rudimentary) neurons in the brain and glial cells developed?

week 24

When can a fetus feel pain?

by week 24

When does a fetus begin preparing for birth?

months 7 and 9

How does a fetus begin preparing for birth

by exercising its muscles and its lungs begin to expand

How much weight and length does a fetus gain in its last month of pregnancy?

approx. 5 lbs and 7”

During the 8th months of pregnancy, a layer of fat develops. Why is this?

serves as insulation and helps baby regulate body temp after birth

by what week is a fetus ready for birth?

at 36 weeks, weighing about 6 pounds and with a length of about 18.5”

By which week are the fetus’ organ systems developed to where the fetus could survive birth without much risk associated with premature birth?

Week 37

Maternal Factors: What complications are more likely for a mother >age 35?

Fertility issues, HTN, Diabetes, Miscarriages, Placenta previa, C-section, premature birth, Stillbirth, baby with genetic disorders.

Maternal Factors: what are environmental teratogens

anything that interferes with normal development

Maternal Factors: why do risk factors develop for pregnancy above the age of 35?

teratogens affect egg quality and reproductive system ages.

Maternal Factors: what are some benefits to older pregnancy?

confident and more stable older parents, children less prone to emotional issues and injuries and perform better on math. Women who delay pregnancy also live longer

Teenage pregnancy: a teenage mother is at a greater risk of having pregnancy complications. what do these include?

anemia and htn

Teenage pregnancy: what are risks for the fetus?

higher risk of being born premature, low birth weight, other problems. Organs may not be fully developed, vision loss and brain bleeding may be present, there may be intestinal problems.

Teenage pregnancy: Very low birth weight babies (<3.3) and low birth weight babies (3.3 - 5.5 lbs) are how much more likely to die?

100 times more likely and more than 5 times more likely, respectively

Teenage pregnancy: when is risk of complications post birth worst

in teenage pregnancies under the age of 15

Teenage pregnancy: why are risk factors higher?

teenagers least likely of all groups to get prenatal healthcare, may eat unhealthy food, drink alcohol, smoke, and take drugs.

Teenage pregnancy: another concern for teenage pregnancy are repeats. Approximately what percentage of teen mothers under 18 have another baby within 2 years of birth?

25%

Gestational Diabetes: what percentage of expectant mothers develop gestational diabetes?

7%

Gestational Diabetes: At what time do most expectant mothers have their glucose levels checked?

24 to 28 weeks of pregnancy

Gestational Diabetes: what could gestational diabetes indicate for the mother?

while it usually goes away post-childbirth, it may indicate an increased risk of developing diabetes later on in life

Gestational Diabetes: what can it cause when left untreated?

premature birth, stillbirth, breathing issues at birth, jaundice, or low blood glucose. Babies might also be heavier

Gestational Diabetes: how can it affect the mom?

untreated can cause preeclampsia (htn and signs of kidneys and iver not functioning),

Gestational Diabetes: what are risk factors?

over 25, being overweight or gaining too much weight, family hx of diabetes, previous gestational diabetes, and race/ethnic group (Latinos, African Americans, Native Americans, Asians, and Pacific Islanders at higher risk)

Gestational Diabetes: how can the risk be reduced?

good diet and maintaing a healthy weight

Gestational Diabetes: how can the risk be reduced in those already at risk (ie, preexisting DM)

by attending all prenatal care appts and following medical advice (risk factors the same as if they had gestational diabetes)

High Blood Pressure and Rh Disease: What is HTN

Pressure against walls of arteries are too high. Can either be gestational or chronic in pregnancy

High Blood Pressure and Rh Disease: when does gestational htn occur>

during pregnancy, but goes away post childbirth. Chronic is when the condition was already present before the pregnancy

High Blood Pressure and Rh Disease: what can HTN during pregnancy cause?

premature birth, low birth weight (>5.5lbs), placental abruption, and even preeclampsia.

High Blood Pressure and Rh Disease: What disease are Rh-mother’s fetus at risk of having?

at risk of having baby with Rh-Anemia

High Blood Pressure and Rh Disease: Why does Rh-anemia occur?

Rh-positive father and negative mother conceive. Fetus is Rh-Positive. Rh-Negative mother’s body mistakenly identifies the fetus as an invader and develops antibodies, cross the placenta, and destroy the fetus’ red blood cells.

High Blood Pressure and Rh Disease: What can Rh-Anemia lead to?

Jaundice, anemia, heart failure, brain damage, and death

Weight Gain During Pregnancy: how many excess calories do women require during pregnancy?

300

Weight Gain During Pregnancy: how much weight should a woman at a healthy weight before pregnancy gain?

gain 25 to 35 pounds total with 1 to 4.5 lbs being gained the first trimester and 1 lb per week during the second and third trimesters.

Weight Gain During Pregnancy: how much weight should an underweight women before pregnancy gain?

28 to 40 lbs total, gaining 1 to 4.5 lbs the first trimester, then 1 lb per week the second and third trimesters.

Weight Gain During Pregnancy: how much weight should an overweight woman before pregnancy gain?

12-25 lbs, gaining 1 to 4.5 pounds the first trimester, and a little more than half a pound during the second and third trimesters.

Weight Gain During Pregnancy: how much weight should an obese woman before pregnancy gain?

11 to 20 lbs total, gaining 1 to 4.5 lbs in the first trimester, then less than half a pound per week in the second and third trimesters.

Stress during pregnancy: what are adverse effects?

premature or low birth weight, issues with baby’s brain development, immune function, and childhood problems with attention and fear

Stress during pregnancy: why does stress cause premature birth or low birth weight?

stress related hormones may affect the mother’s immune system causing this. Additionally, poor choices (alcohol consumption, drugs, etc) may be made during stress

Depression Pregnancy: How many women are treated for depression before and after pregnancy?

one in seven. Women who have experienced depression prior to pregnancy are at higher risk of having issues with depression during

Depression Pregnancy: What percentage of women take an antidepressant during pregnancy?

13%.

Depression Pregnancy: Women must discuss antidepressant options with their providers. Why is this?

birth defects happen 2 or 3 times more often in women who are taking certain SSRIs/

Complications of Pregnancy: What are some examples of minor complications?

Nausea (mainly in first 3 to 4 months of pregnancy, due to surge of estrogen), heartburn, gas, hemorrhoids, backache, leg cramps, insomnia, constipation, SOB, and varicose veins (due to heavy weight of belly)

Complications of Pregnancy: What are some examples of major complications that pose health risks to mother and child and often require hospitalization?

Ectopic pregnancy (occurring in 1 in 50 pregnancies. Number increasing due to cases of chlamydia and PID) abdominal pain, vaginal bleeding, nausea, fainting symtpoms.

Preeclampsia/Toxemia, characterized by a sharp rise in BP, leakage of protein into urine as a result of kidney problems, swelling of hands feet and face, reaches eclampsia when seizures begin, and second leading cause of maternal death.

Complications of Pregnancy: What is the most common major complication?

preeclampsia, affecting 5-10% of pregnancies globally and leading to 40-60% of maternal deaths in developing countries. Lower in US affecting 3-5%.

Complications of Pregnancy: what are risk factors for preeclampsia?

obesity, diabetes, first pregnancy, carrying twins

Complications of Pregnancy: How many American women die during pregnancy each year? How many deaths out of those are preventable?

700, 60%

Complications of Pregnancy: Out of preventable maternal deaths, what were the causes of death?

bleeding, infections, heart problems

Complications of pregnancy: How many women die during childbirth around the world each day? what are statistics?

1000, rates highest in sub-saharan Africa and South Asia, but a substantial decrease with development of more clinics in these areas and midwives.

Complications of Pregnancy: what percentage end in spontaneous abortion?

in 20 to 40% of undiagnosed pregnancies, and in 10% of known pregnancies. TYpically prior to 12th week of pregnancy and due to chromosomal abnormalities.

Complications of Pregnancy: why would repeated miscarriages happen?

Due to Chromosomal, Amniotic, or Hormonal problems, but defective sperm could also be issue

Childbirth: What is the Lamaze Method?

brought to US in 1950s, teaches women how to be in more control. Teaches muscle relaxation, breathing through contractions, focal point to look at, and support person who goes through the training process