Genetics, Conception, Fetal Development & Reproductive Technology (1) Flashcards
Birth Rate
number of live births per 1000 people
Infant Mortality
number of deaths of infants under 1 year of age per 1000 live births (before the first birthday)
Neonatal Mortality
number of deaths of infants less than 28 days of age per 1000 live births
Maternal Death or Mortality
number of deaths from any cause related to or aggravated by pregnancy or its management during the pregnancy cycle (includes 42 day PP period) per 100,000 live births
Largest Concerns Impacting Health of Mothers and Infants Today:
Adolescent pregnancy Tobacco use/ vaping Substance abuse in pregnancy Obesity Health disparities (preventable differences in the burden of disease, injury, violence or opportunities to achieve optimal health)
Tobacco Use in Pregnancy
Increase risk of growth restriction and low birth weight infants d/t impaired oxygenation.
Obesity in Pregnancy (BMI >30)
Maternal risk of:
Gestational HTN and preeclampsia
Gestational diabetes
Thromboembolism
Increase fetal/infant risk of:
Birth injuries r/t macrosomia
Health Disparities and Pregnancy
low income women are less likely to seek early and regular care d/t:
transportation, financial, and communication
they may have different attitudes about the importance of care
Genes
DNA + protein
*each human cell contains 46 chromosomes w/ 22 autologous pairs of chromosomes and one pair of sex chromosomes (XX or XY)
Genome: organisms COMPLETE set of DNA
Genotype: person’s genetic makeup
Phenotype: person’s outward expression of those genes
Abnormalities of Chromosome Number
Trisomies: the presence of an extra chromosome (three instead of the usual pair)
Abnormalities of Chromosome Structure
Translocation: chromosome breaks and a portion of it reattaches to different chromosomes
Duplications: region of a chromosome is repeated
Deletions: area of the chromosome is deleted
Prenatal (Antepartum) Testing
early genetic screening for genetic disorders like trisomy 21
Who should be offered genetic testing and why?
couples at higher risk for conceiving a child w/ genetic disorder:
maternal age >35YO
prior pregnancy w/ genetic or newborn abnormality
personal hx of genetic disorder
family hx of genetic disorder
why? b/c it provides parents w/ options
Uterus
3 layers:
outer = fundus, muscle fibers run up and down to help push baby out
middle = fibers run in chicken wire like formation so it can clamp down and prevent hemorrhage after birth
inner = cervix, fibers run horizontally so muscle can flatten out and dilate when baby is ready to be delivered
*fibers run in different directions
Where does fertilization occur?
Fallopian tubes at the Ampulla
Ovaries
Store and develop follicles (present from birth)
Follicles secrete hormones (primary source)
- estrogen: contribute to femaleness
- progesterone: hormone of pregnancy
Ovarian Cycle
3 phases pertaining to oocyte development:
Follicular phase (days 1-14) Ovulatory phase: begins when estrogen levels peak and ends w/ release of oocyte from follicle Luteal phase (days 15-28)
Endometrial Cycle
3 phases pertaining to changes in the endometrium based on hormonal changes from ovarian cycle:
Proliferative Phase: begins after menstruation and ends w/ ovulation
Secretory Phase: begins after ovulation and ends when menses begins
Menstrual phase: sloughing of the endometrial tissue
Female Infertility Causes
Ovulatory dysfunction
Tubal & pelvic pathology
Cervical Mucus Factors
Male Infertility Causes
Endocrine Problems w/ spermatogenesis Sperm antibodies Sperm transport Disorders of intercourse (ED)
Gametogenesis
oogenesis
spermatogenesis
mitosis: cell divides forming two identical daughter cells
meiosis: two cell divisions producing half the number of chromosomes
Fertilization
Fertilization occurs -> single cell Zygote
3 days after fertilization -> Morula (16 cell sphere)
5 days after fertilization -> Blastocyst (composed of embryoblast (will become embryo) and trophoblast (will become chorion)
Implantation: occurs 5-10 days after fertilization, blastocyst burrows into endometrium which is now called decidua (lining of uterus)
Dizygotic Twins
fraternal twins
2 ova and 2 sperm
2 placentas, 2 chorions & 2 amnions
NOT genetically the same
*happens in family lines as women may be predisposed via genetics to release two eggs at once
Monozygotic Twins
identical twins
single fertilized ovum
same gender, same genetic material
usually 1 placenta # of amnions and chorions depends on timing of split
not hereditary
Fetal Membranes
2 membranes for expandable amniotic sac
Amnion: inner membrane produces the amniotic cavity (develops from the embryoblast)
Chorion: outer membrane or fetal side of placenta encircles the amnion, embryo and yolk sac (develops from the trophoblast)
BAC: baby, amnion, chorion
TORCH Infections
T: Toxoplasmosis O: Other (syphilis, parvo, varicella) R: Rubella C: Cytomegalovirus H: Herpes/varicella
Umbilical Cord
One vein, two arteries (AVA)
Vein delivers oxygenated blood (larger of the vessels)
Arteries carry deoxygenated blood
Wharton’s Jelly: specialized connective tissue that prevents compression of umbilical cord
Fetal Circulatory System: Functions and Unique Features
Functions:
maintains blood flow to placenta
provides fetus with O2 and nutrients
removes CO2 and waste products
Unique Feature: high levels of O2 blood flows through umbilical vein to fetus
Fetal Shunts
Ductus venosus: in liver, connects umbilical vein to inferior vena cava (bypassing liver) enabling the oxygenated blood to enter the right atrium
Foramen Ovale: opening between the left and right atria, oxygenated blood is shunted to the left atrium
Ductus Arteriosis: connects the pulmonary artery with the descending aorta, shunts blood to aorta and limits amounts going to lungs.
Placental Functions
fetal respiration: site of metabolic gas exchange
nutrition: nutrients and O2 transferred through diffusion and active transport
excretion: fetal waste and CO2 is transferred back to maternal blood sinuses by diffusion
hormone production: hCG, progesterone, estrogen, hPL (promotes fetal growth)
Immunologic Properties
Amniotic Fluid Functions
- cushion to protect the embryo against mechanical injury
- help control embryo’s temp (reliant on mother)
- permits symmetrical growth and development
- prevents adherence of fetus to amnion allowing freedom of movement
- allows umbilical cord to be free from compression
- acts as a wedge in labor
- provides fluid for analysis to determine fetal health and maturity
