Prenatal Development and Birth

Flashcards about prenatal development, fertilization, and birth complications

Fertilization/Conception

The process by which sperm and ovum fuse to form a single cell.

When is fertilization most likely to occur?

About 14 days after the beginning of the woman's menstrual period.

Zygote

The new cell formed by the fusion of the ovum and the sperm.

Cilia

Tiny hair-like cells that sweep the ovum through the fallopian tubes towards the uterus.

How long can sperm maintain their ability to fertilize an ovum?

Up to 48 hours.

How long can an ovum be fertilized after release from the ovary?

About 24 hours.

What are the three stages of the prenatal period?

The Germinal Stage/Period of the Zygote, the Embryonic Stage/Period of the Embryo, and the Fetal Period.

Germinal Stage Timeframe

Fertilization to the end of the second week.

What happens during the Germinal Stage?

The organism divides, becomes more complex, and is implanted in the wall of the uterus.

Blastocyst

A fluid-filled sphere that the zygote transforms into during its passage through the fallopian tube.

What are the three phases of implantation?

Apposition, Adhesion, and Invasion

Embryonic Disk

A thickened cell mass on one side of the blastocyst from which the baby will develop.

What organs develop from the outer layer of cells of the blastocyst?

The Placenta, the Umbilical Cord, and the Amniotic Sac.

What is the timeframe for the Embryonic Period?

End of the 2nd week to the end of the 2nd lunar month

What happens during the Embryonic Period?

Development of a recognizable human being begins.

What are the three distinct layers that is differentiated during the embryonic period?

Ectoderm, Endoderm, and Mesoderm.

What does the ectoderm develop into?

Nails, hair, teeth, sensory organs, outer layer of skin, nervous system, brain, and spinal cord.

What does the endoderm develop into?

Digestive system, liver, pancreas, salivary glands, and respiratory system (lungs).

What does the mesoderm develop into?

Inner layer of skin, muscles, skeleton, circulatory, and excretory systems.

Amniotic Sac

Contains amniotic fluid, a watery liquid in which the developing embryo floats and which serves as a protective buffer against physical shocks and temperature changes.

Placenta

Connects the embryo to the uterine wall, delivers oxygen and nourishment to the embryo, and removes its body wastes.

Umbilical Cord

Connects the embryo at the abdomen to the placenta.

What occurs during the 3rd week of prenatal development?

Rapid development of the nervous system.

What occurs during the 4th week of prenatal development?

The heart begins to beat.

What occurs during the 5th week of prenatal development?

Eyes and ears begin to emerge, body buds give clear evidence of becoming arms and legs, and the head area is the largest part of the body.

What occurs during the 6th & 7th week of prenatal development?

Fingers begin to appear on the hands, an outline of the toes is seen, and the beginnings of the spinal cord are visible.

Organogenesis

The organs are formed.

What occurs during the 8th week of prenatal development?

95% of the body parts are formed and general body movements are detected.

What is the timeframe for the Fetal Period?

Beginning of the third month to birth.

What happens during the Fetal Period?

The fetus grows rapidly both in height and weight.

What occurs during the 3rd month of prenatal development?

Sex organs appear and it is possible to determine the baby's sex.

Quickening

Kicking of the fetus

Lanugo

A wooly hair that covers the body.

Viability

The ability to survive if born, typically attained around the 7th month.

What happens during the 8th and 9th months of prenatal development?

Preparation for birth goes on, senses are ready to function, and the brain is 25% of its adult weight.

Teratogens

Agents that can cause abnormalities, including drugs, chemicals, infections, pollutants, and the mother's physical state.

STORCH Diseases

Syphilis, Toxoplasmosis, Other infections, Rubella, Cytomegalovirus, Herpes.

What can untreated syphilis cause in a fetus/

Blindness, mental retardation, and deafness.

Toxoplasmosis

A disease caused by a protozoan that may cause damage to the nervous system; transmitted by animals, especially cats.

What issues can Rubella (German Measles) cause if contracted by pregnant women?

Congenital heart disorder, cataracts, deafness, or mental retardation.

Cytomegalovirus (CMV)

A virus that can cause damage ranging from MR to blindness, deafness, and even death.

What can analgesics, anesthetics or barbiturates cause in a fetus?

Respiratory depression.

What can aspirin cause in a fetus?

Blood disorders, low intelligence, and low birth weight.

What can Anti-convulsive drugs cause in a fetus?

Cleft lip and cleft palate.

What can quinine cause in a fetus?

Hearing loss.

What can Isotretinoin cause in a fetus?

Abnormalities in the heart, head, neck, CNS, lack of ears, behavioral problems, and brain damage.

What can Steptomycin and Tetracycline cause in a fetus?

Hearing loss, inhibition of bone growth, and discolored teeth.

Phocomelia

Limbs missing, feet and hands attached to torso like flippers.

What hormone, when given to pregnant women to prevent miscarriages, caused female children to have unusually high rates of cancer of the vagina and malformations of the uterus?

DES Diethyl Stilbestrol.

What effect do opiates like Heroin, Morphine, and Codeine have on the fetus?

Addicted mothers have children who are also addicted and go through withdrawal symptoms.

What effect does Marijuana have on the fetus?

Fetus has tremors, startles, high pitched cry, and reduced attention to the environment.

What effect does Smoking have on the fetus?

Low birth weight, prematurity, miscarriages, and sudden infant death syndrome (SIDS).

What can excessive consumption of alcohol by the mother lead to for the child/

Fetal Alcohol Syndrome (FAS)

What is a problem resulting from the interaction of heredity with the prenatal environment?

Rh incompatibility.

What condition results when a fetus's blood contains the Rh factor but the mother's blood does not?

Erythroblastosis fetalis.

What can a vaccine can be given to prevent Rh disease?

Can be given to the Rh -ve mother which, when administered within 3 days after childbirth or abortion, will prevent her body from making antibodies.

What can food low in iron lead to?

Stillbirth, death, and brain damage of the baby.

What can a Deficiency in vitamins and proteins lead to?

Premature birth, smaller children with potential IUGR neurological deficiency.

What maternal age has a greater chance for mutations during meiosis as well as multiple births due to multiple releases of ova.

Older women, over 35 years.

What affect can occurs due to high blood pressure

Hydrocephalic - fluid in the brain, Cretinism, and development of mental disorders.

What could result of the mother's diabetes is not controlled during pregnancy?

Miscarriage, metabolic disturbances like respiratory and circulatory, and intrauterine death.

What affects does maternal stress have

Miscarriages, prematurity, low birth weight, respiratory illness, and high fetal movements.

Why should medical X-rays exposure should be avoided during the first 3 months of pregnancy/

Radiation causes gene mutation, minor changes that alter a gene to produce a new, often harmful characteristic.

What condition is found in result to additional chromosomes in the 21st pair/

Down's Syndrome.

Kline Felter's Syndrome

Male has XXY - small testes, MR, variety of personality and psychiatric problems, sterile and has many female characteristics.

Turner's Syndrome

Female has XO instead of XX, Small in stature, normal intelligence, webbed necks, and unusually shaped mouth and ears.

What are the characteristics of an XYY male?

Taller than usual and has anti social impulses. High crime rate.

What are the characteristics of an XXX female?

Short-term memory and impairment of verbal skills.

What disease affected the male heirs of Europe, and indicates a tendency to bleed internally in joints and muscles and exhibits poor clotting of blood?

Hemophilia Royal disease

Phenylketonuria (PKU)

Recessive gene leads to absence of enzyme necessary to metabolize certain types of protein found in milk.

Tuchmann and Duplessis (1965) Principle Of Teragontes

The effects of teratogens vary in the developmental stages. The zygote period is less vulnerable than the embryonic period.

Clegg (1975) principle of Teratogens:

In the fetal stage, the teratogen-induced abnormalities occur only in locations or systems that are still maturing such as cerebellum, palate, cardiovascular and urogenital structures.

When the Brain and Eyes as legs are most vulnerable for teragtens?

The most vulnerable periods for the brain 10-25 days, eyes 25-40 days, and legs 24-36 days.

Birth

Definition: Birth is the transition between dependent existence in the uterus and life as a separate organism.

What occurs a few weeks before the actual birth?

Lightening and Braxton-Hicks contractions.

A few weeks before birth, the head of the infant generally turns downwards, which ensures that it will be born head first. The uterus simultaneously sinks downwards and forwards.

Lightening

What are the three stages of the birth process?

Labor, Delivery, and Afterbirth

Labor Stage

During labor the strong muscle fibers of the uterus rhythmically contract, pushing the infant downward to toward the birth canal (the vagina).

Delivery Stage

Delivery begins once the infant's head passes through the cervix (the neck of the uterus) and ends when the baby has completed its passage through the birth canal.

Occurs when the widest diameter of the baby's head is at the mother's vulva (the outer entrance to the vagina).

Crowing

Afterbirth process

After the baby's birth, the uterus stops its contractions for about 5 minutes. The contractions then resume and the placenta separates from the uterus, and is forced into the vagina and finally expelled.

APGAR scoring System

Heart rate, Respiratory effort, Reflex irritability, Muscle tone,, Color, appearance.

At what APGAR score, the infant is in serious danger, and emergency medical attention is required.

If the score is 3 or below

An approach designed to reduce pain and medical intervention and to make childbirth a rewarding experience for parents.

Natural, or prepared, childbirth

What does a typical natural childbirth program consists of?

Classes, Relaxation and breathing techniques, and Labor coach.

Mild drugs that lessen pain.

Analgesias

A stronger type of painkiller that blocks sensation, generally injected into the spinal column to numb the lower half of the body.

Anesthesia

Injury sustained at the time of birth, may be caused by anoxia (oxygen deprivation), diseases or infections, or mechanical injury.

Birth trauma

What are the 3 stages of Labor?

dilation and effacement of the cervix, birth of the baby, and delivery of the placenta.

How much long does the first stage of labor can last

About 12-14 hours for the first baby and 4-6 hrs after

Why it is important to become cervix thin to nothing during the labor?

A clear channel from the uterus into the virginia is created.

Oxygen deprivation

Anoxia

Injury sustained at the time of birth.

Birth trauma

Galactosemia

Routine screening of all newborn babies for such rare conditions as PKU

Referring to a fetus not yet born as of two weeks after the due date or forty-two weeks after the mother's last menstrual period.

Postmaturity

Weight of less than 5 pounds (2,500 grams) at birth because of prematurity or being small for date.

Low birthweight

Infants born before completing the thirty-seventh week of gestation.

Preterm

Infants whose birthweight is less than that of 90 percent of babies of the same gestational age

Small-for-date

Hyaline membrane disease

An abnormally formed sperm.