growth & development: prenatal development and birth

266 days; 38 wks, 9 months

what is the length of pregnancy

gestational age

from the first day of the last menstrual period

40 weeks; 280 days

how long is the typical gestational age

2 weeks after the first day of the last menstrual period

when is the predicted time of conception

one week before to one week after the due date; 39 weeks- 40 wks and 6 days

what is considered full term

germinal period

the time from conception to implantation in the uterus and typically lasts two weeks; rapid cell division beginning of cell differentiation but half of zygotes do not survive

embryonic period

occurs from the third to the eighth week after conception and is when organogenesis (formation of organs) occurs

hair, skin, nervous system

what forms during the embryonic period and is part of the ectoderm

muscles, bones, circulatory systems

what forms during the embryonic period and is part of the mesoderm

digestive system and lungs

what forms during the embryonic period and is part of the endoderm

6-8 weeks

when is the heartbeat detectable by ultrasound

neural tube

what begins to form at 3-4 weeks by the neural plate folding up; is the beginnings of the brain and if not done properly spina bifida results

fetal period

the time from the ninth week after. conception until birth; involves part of first trimester and then all of the second and third

0-14 weeks

when is the first trimester

14-26 weeks

when is the second trimester

27-40 weeks

when is the third trimester

cephalocaudal and proximodistal growth, sex organs become visible, heartbeat becomes detectable by stethescope, quickening, and age of viability

what occurs during the fetal period

3 months

when are the reproductive organs visible through ultrasound

20 weeks

when is the heartbeat detectable by stethoscope

18-20 wks

when does quickening (movement of the fetus) occur

activation of CNS and sufficient development of respiratory system

what determines the age of viability

22 weeks gestation/ 20 weeks after conception

when is age of viability

proximal to distal

how does prenatal growth of the brain occur

hindbrain and midbrain

what part of the brain develops first

proliferation, migration, differentiation, synaptogenesis, and myelination

what occurs for the CNS to develop

20 weeks to puberty

when does synaptogenesis of the CNS occur

10-20 weeks

when does proliferation of the CNS occur

12-24 weeks

when does migration of the CNS occur

24 weeks gestational age to 10 years

when does myelination of the CNS occur

development of heart and lungs

what is the final trimester a critical period for

final trimester

provides time for extensive growth and folding in cortex; expansion and contraction of lungs; final maturation of heart valves, arteries, and veins

4.5 lbs

in the last 3 months of pregnancy (final trimester) how much does the baby grow if the typical avg size is 7.5 lbs at birth

teratogens

any disease, drug, or other environmental agent that can harm a developing fetus

deformities of certain extremities

what might thalidomide cause if taken during the critical period

low birth weight or preterm birth and an increase risk of asthma

what does tobacco typically cause

increased miscarriage risk

what does radiation typically cause

fetal alcohol syndrome or intellectual disability

what does alcohol typically cause

genotype of organism, course of prenatal development, the specific aspect of development, and dosage

what does the effect of the teratogen depend on

fetal brain signals release hormones to trigger the female’s uterine muscles

how is birth triggered

9-14 hours

what is the average duration of labor for the firstborn because it typically decreases for subsequent births

12-24 hrs before birth

when does stage 1 of labor occur

contractions and cervix enlarges to 4 inches

what occurs during stage 1 of labor

15-20 minutes to an hour

when does stage 2 of labor occur

fetus’s head passes through the cervix to vagina and the baby emerges from the mother

what occurs during stage 2 of labor

minutes after birth

when does stage 3 of labor occur

placenta is expelled

what occurs during stage 3 of labor

head down and face backwards facing the spine

what is the ideal position for a baby to be birthed

the baby’s head is up

what is a breech position for birth

anoxia, breech presentation, C-section, complicated delivery, and medication for pain relief

what are the perinatal hazards

anoxia

pinched umbilical cord and sedatives are typically given

breech presentation

if undetected there is risk for anoxia and may also lead to a brachial plexus injury

C-section

may increase complications

medication for pain relief

what could be hazardous if it is in a large dose to where the infant becomes drugged as well

age and exposure to toxins that affect the sperm

what could affect the health of the fetus from the paternal side

age, emotional condition, and nutritional condition

what could affect the health of the fetus from the maternal side

causes the fetus to have a faster heart rate, low-birth rate, preterm, birth complications, more irritable, and prone to crying

how can prolonged or severe emotional stress and anxiety during pregnancy

20-34 years

what is the age range associated with the lowest mortality rate

prevents spina bifida

why should prospective mothers take a daily multivitamin with folic acid

plan it, multivitamin, avoid binge drinking, update immunizations against teratogenic viruses, gain/lose weight, reassess use of prescription drugs, and develop daily exercise habits

what should prospective mothers do if they are planning on becoming pregnant