MATERNITY EXAM 1 1
Prenatal Development
A&P:
● Sperm live ~ 3 days
● Eggs live ~ 24hrs
● No sex for several days before/after ovulation to avoid pregnancy
Signs of ovulation:
● Usually occurs on day 14
● Ovulatory mucus = more abundant, clear, slippery, smooth (like egg whites) = spinnbarkeit
● Some women have localized abdominal pain that coincides with ovulation = mittelschmerz
● Subtle temperature changes:
○ Slight ↓ in basal body temp 1-2 days before ovulation (before ovulation: 97-97.5)
○ ↑ 1-2 days after ovulation (0.5-1 degrees) and stays high until menses (after ovulation: 97.6-98.6)
● Open cervical os
● Ferning under microscope
Implantation:
● Ideally want egg to travel down and implant in uterus
● Fertilization occurs in outer horn (ampulla = outer third)
● Ovary releases egg every 28 days
● If egg becomes fertilized & gets trapped in tube = ectopic preg
○ Fallopian tube can burst = emergency
● Zygote (fertilized ovum) takes 3-4 days to enter uterus
● 7-10 days to complete process of nidation (implantation)
Menstruation: if no conception occurs
● Usually count day 1 as the first day of bleeding
● Average days in cycle = 28
● Progesterone and estrogen levels drop → triggering menses
*Periods of Prenatal Development:
● Pre Embryonic: 0-2 weeks
● Embryonic: 2-8 weeks (day 15-8 weeks)
○ Basic structure of all major body organs develop
○ Most critical time
○ Teratogenic substances cause abnormalities (ex:
accutane)
● Fetal: 8 weeks-birth (most of pregnancy)
● Duration of pregnancy: 40 weeks or 266 days
● Fetal circulation spans all 3 stages
*FDA Pregnancy Risk Categories:
A. No evidence of risk to fetus
B. No risk by animal studies OR animal studies show an adverse effect but studies with women show no risk to fetus
C. Fetal risk demonstrated in animal studies but no adequate studies in humans OR no animal studies and no
adequate studies in humans (benefits may warrant use of med in pregnancy)
D. Positive evidence of human fetal risk (may be no safe alternatives)
X. Animal or human beings have demonstrated fetal abnormalities/adverse rxn. Indicates evidence of fetal
risk (risk clearly outweighs benefits)
, MATERNITY EXAM 1 2
HESI pg. 241-243, 243-247: Anatomy & Physiology of Reproduction
The Menstrual Cycle
● Most women have ovulatory cycles within 24 months after menarche (first menstruation)
● ~ Menarche age in US = 12.87yrs
● Pregnancy can occur after first menstrual cycle
● Sexually active girl can conceive prior to first menstrual cycle
● Menstrual phase varies in length in most women
● Ovulation occurs approximately 14 days before the next menstrual cycle
● To avoid pregnancy a women should abstain from unprotected sex during her fertile days
○ Most fertile days = day before ovulation & day of ovulation
○ Fertile period begins 4-5 days prior to ovulation and ends 24-48 hrs after ovulation
○ A couple must avoid unprotected sex for several days before an anticipated ovulation and for 3
days after ovulation to prevent pregnancy
■ Sperm can live in a woman's body ~ 4-5 days
■ Eggs live ~ 24-48 hrs after being released
Phases of Menstrual Cycle (4)
1. Menstrual phase: day 1 - 5
○ Shedding of endometrium occurs in form of uterine bleeding
2. Proliferation (follicular) phase: day 5 - ovulation
○ Begins the first day of menstruation and ends 14 days later (28 day cycle)
○ Anterior pituitary secretes follicle-stimulating hormone (FSH)
○ Preovulatory surge of luteinizing hormone (LH) converts follicle to corpus luteum
i. Corpus luteum produces progesterone
3. Ovulatory phase:
○ 2 days prior to ovulation = rise in LH and FSH, decrease in follicular estrogen, and rise in
progesterone secretion
○ Final maturation of single follicle and release of its mature ovum
○ Ovulation marks the beginning of the luteal phase (~ 14 days into the menstrual cycle)
○ Mature follicle ruptures and ovum is released from the ovary
○ Ovum picked up by fimbriated end of the fallopian tube and transported to uterus
4. Luteal phase: immediately after ovulation and ends with menstruation
○ Postovulatory phase requires 13-15 days
○ Corpus luteum reaches peak functional activity 8 days after ovulation secreting estrogen and
progesterone
○ Fertilized ovum implanted in endometrium
○ Absence of implantation = corpus luteum regresses, ↓ estrogen and progesterone, the
endometrium is shed via menstruation
5. Endometrial cycle:
○ Menstrual phase: periodic vasoconstriction in upper layers of endometrium initiates shedding of
functional ⅔ of endometrium
○ Proliferative phase: depends on estrogen
○ Secretory phase: day of ovulation - 3 days prior to next menstrual period
○ Ischemic phase:
i. Blood supply to functional endometrium blocked and necrosis occurs
ii. Functional layer separates from basal layer & menstruation begins (day 1 of next cycle)
, MATERNITY EXAM 1 3
Fertilization
Conditions for fertilization:
● Postcoital test demonstrates live, motile, normal sperm present in cervical mucus
● Fallopian tubes patent
● Endometrial biopsy indicates adequate progesterone and secretory endometrium
● Semen supportive to pregnancy: 2ml semen, at least 20 million sperm/ml, >60% normal & >50% motile
Maternal Physiologic Changes During Pregnancy
Pregnancy length: counted from the first day of ● 9 calendar months
LMP Pregnancy is divided into three 13 week trimesters:
● 280 days ● First trimester: first day of LMP - 13 weeks
● 40 weeks ● Second trimester: 14 weeks - 26 weeks
● 10 lunar months (28 day) ● Third trimester: 27 weeks - 40 weeks
Fetal Circulation
Carry highly oxygenated blood to vital areas (heart/brain) while first shunting it away from less vital areas (lungs and liver)
3 Important Shunts:
1. Ductus venosus: connects umbilical vein to inferior vena cava
2. Ductus arteriosus: connects aorta to main pulmonary artery
3. Foramen ovale: anatomic opening b/w R and L atrium
a. Goal = bypass the lungs (fetus can’t breathe yet)
b. Sends a little blood to lungs for development but most
goes from R atrium to L atrium
Umbilical Cord: the lifeline
● Provides closed circulation from fetus to placenta
● Wharton’s jelly: jelly substance within umbilical cord
● Average cord = 22 in long, 1 in thick
● Inside the umbilical cord**: 2 arteries, 1 large vein
○ One umbilical vein: carries oxygenated
blood from
placenta to fetus
○ Two umbilical arteries: carry deoxygenated
blood from
fetus to placenta
Amniotic Fluid:
● Source of oral fluid & repository for waste of fetus
● Maintain fetal body temp
● Allows umbilical cord to be free from compression & cushions from trauma
● Permits symmetrical growth
● Prevents adherence to amnion (sack)
● Provides space for free movement
○ 1 cause of stillborn is cord accident often due to insufficient amniotic fluid
Oligohydramnios (not enough fluid) Hydramnios (too much fluid)
Associated with uteroplacental insufficiency & fetal renal Associated with maternal diabetes, neural tube defects,
abnormalities chromosomal deviations, and other malformations
<500 ml at term > 2,000 ml
Increased risk of cord prolapse
Prenatal Development
A&P:
● Sperm live ~ 3 days
● Eggs live ~ 24hrs
● No sex for several days before/after ovulation to avoid pregnancy
Signs of ovulation:
● Usually occurs on day 14
● Ovulatory mucus = more abundant, clear, slippery, smooth (like egg whites) = spinnbarkeit
● Some women have localized abdominal pain that coincides with ovulation = mittelschmerz
● Subtle temperature changes:
○ Slight ↓ in basal body temp 1-2 days before ovulation (before ovulation: 97-97.5)
○ ↑ 1-2 days after ovulation (0.5-1 degrees) and stays high until menses (after ovulation: 97.6-98.6)
● Open cervical os
● Ferning under microscope
Implantation:
● Ideally want egg to travel down and implant in uterus
● Fertilization occurs in outer horn (ampulla = outer third)
● Ovary releases egg every 28 days
● If egg becomes fertilized & gets trapped in tube = ectopic preg
○ Fallopian tube can burst = emergency
● Zygote (fertilized ovum) takes 3-4 days to enter uterus
● 7-10 days to complete process of nidation (implantation)
Menstruation: if no conception occurs
● Usually count day 1 as the first day of bleeding
● Average days in cycle = 28
● Progesterone and estrogen levels drop → triggering menses
*Periods of Prenatal Development:
● Pre Embryonic: 0-2 weeks
● Embryonic: 2-8 weeks (day 15-8 weeks)
○ Basic structure of all major body organs develop
○ Most critical time
○ Teratogenic substances cause abnormalities (ex:
accutane)
● Fetal: 8 weeks-birth (most of pregnancy)
● Duration of pregnancy: 40 weeks or 266 days
● Fetal circulation spans all 3 stages
*FDA Pregnancy Risk Categories:
A. No evidence of risk to fetus
B. No risk by animal studies OR animal studies show an adverse effect but studies with women show no risk to fetus
C. Fetal risk demonstrated in animal studies but no adequate studies in humans OR no animal studies and no
adequate studies in humans (benefits may warrant use of med in pregnancy)
D. Positive evidence of human fetal risk (may be no safe alternatives)
X. Animal or human beings have demonstrated fetal abnormalities/adverse rxn. Indicates evidence of fetal
risk (risk clearly outweighs benefits)
, MATERNITY EXAM 1 2
HESI pg. 241-243, 243-247: Anatomy & Physiology of Reproduction
The Menstrual Cycle
● Most women have ovulatory cycles within 24 months after menarche (first menstruation)
● ~ Menarche age in US = 12.87yrs
● Pregnancy can occur after first menstrual cycle
● Sexually active girl can conceive prior to first menstrual cycle
● Menstrual phase varies in length in most women
● Ovulation occurs approximately 14 days before the next menstrual cycle
● To avoid pregnancy a women should abstain from unprotected sex during her fertile days
○ Most fertile days = day before ovulation & day of ovulation
○ Fertile period begins 4-5 days prior to ovulation and ends 24-48 hrs after ovulation
○ A couple must avoid unprotected sex for several days before an anticipated ovulation and for 3
days after ovulation to prevent pregnancy
■ Sperm can live in a woman's body ~ 4-5 days
■ Eggs live ~ 24-48 hrs after being released
Phases of Menstrual Cycle (4)
1. Menstrual phase: day 1 - 5
○ Shedding of endometrium occurs in form of uterine bleeding
2. Proliferation (follicular) phase: day 5 - ovulation
○ Begins the first day of menstruation and ends 14 days later (28 day cycle)
○ Anterior pituitary secretes follicle-stimulating hormone (FSH)
○ Preovulatory surge of luteinizing hormone (LH) converts follicle to corpus luteum
i. Corpus luteum produces progesterone
3. Ovulatory phase:
○ 2 days prior to ovulation = rise in LH and FSH, decrease in follicular estrogen, and rise in
progesterone secretion
○ Final maturation of single follicle and release of its mature ovum
○ Ovulation marks the beginning of the luteal phase (~ 14 days into the menstrual cycle)
○ Mature follicle ruptures and ovum is released from the ovary
○ Ovum picked up by fimbriated end of the fallopian tube and transported to uterus
4. Luteal phase: immediately after ovulation and ends with menstruation
○ Postovulatory phase requires 13-15 days
○ Corpus luteum reaches peak functional activity 8 days after ovulation secreting estrogen and
progesterone
○ Fertilized ovum implanted in endometrium
○ Absence of implantation = corpus luteum regresses, ↓ estrogen and progesterone, the
endometrium is shed via menstruation
5. Endometrial cycle:
○ Menstrual phase: periodic vasoconstriction in upper layers of endometrium initiates shedding of
functional ⅔ of endometrium
○ Proliferative phase: depends on estrogen
○ Secretory phase: day of ovulation - 3 days prior to next menstrual period
○ Ischemic phase:
i. Blood supply to functional endometrium blocked and necrosis occurs
ii. Functional layer separates from basal layer & menstruation begins (day 1 of next cycle)
, MATERNITY EXAM 1 3
Fertilization
Conditions for fertilization:
● Postcoital test demonstrates live, motile, normal sperm present in cervical mucus
● Fallopian tubes patent
● Endometrial biopsy indicates adequate progesterone and secretory endometrium
● Semen supportive to pregnancy: 2ml semen, at least 20 million sperm/ml, >60% normal & >50% motile
Maternal Physiologic Changes During Pregnancy
Pregnancy length: counted from the first day of ● 9 calendar months
LMP Pregnancy is divided into three 13 week trimesters:
● 280 days ● First trimester: first day of LMP - 13 weeks
● 40 weeks ● Second trimester: 14 weeks - 26 weeks
● 10 lunar months (28 day) ● Third trimester: 27 weeks - 40 weeks
Fetal Circulation
Carry highly oxygenated blood to vital areas (heart/brain) while first shunting it away from less vital areas (lungs and liver)
3 Important Shunts:
1. Ductus venosus: connects umbilical vein to inferior vena cava
2. Ductus arteriosus: connects aorta to main pulmonary artery
3. Foramen ovale: anatomic opening b/w R and L atrium
a. Goal = bypass the lungs (fetus can’t breathe yet)
b. Sends a little blood to lungs for development but most
goes from R atrium to L atrium
Umbilical Cord: the lifeline
● Provides closed circulation from fetus to placenta
● Wharton’s jelly: jelly substance within umbilical cord
● Average cord = 22 in long, 1 in thick
● Inside the umbilical cord**: 2 arteries, 1 large vein
○ One umbilical vein: carries oxygenated
blood from
placenta to fetus
○ Two umbilical arteries: carry deoxygenated
blood from
fetus to placenta
Amniotic Fluid:
● Source of oral fluid & repository for waste of fetus
● Maintain fetal body temp
● Allows umbilical cord to be free from compression & cushions from trauma
● Permits symmetrical growth
● Prevents adherence to amnion (sack)
● Provides space for free movement
○ 1 cause of stillborn is cord accident often due to insufficient amniotic fluid
Oligohydramnios (not enough fluid) Hydramnios (too much fluid)
Associated with uteroplacental insufficiency & fetal renal Associated with maternal diabetes, neural tube defects,
abnormalities chromosomal deviations, and other malformations
<500 ml at term > 2,000 ml
Increased risk of cord prolapse
