OB Basics Flashcards
Adult Derivatives of the Urogenital Sinus, Female
Lower 3/4 of the vagina
Vestibule (including vestibular glands)
Bladder
Urethra (including urethral and paraurethral glands)
Adult Derivatives of the Urogenital Sinus, Male
Bladder
Urethra
Prostate
Bulbourethral glands
Scrotal ligament (male) : _________ (female)
Gubernaculum testis
Female: Round ligament of the uterus
Timeline for the hormones of sexual differentiation
7th week: SRY gene activated -> TDF
8th week: MIH and Testosterone
9th-12th week: DHT secretion begins
Male Development: Primary sex cords: Rete testes + mesonephric remnants: Mesenchymal thickening: Mesothelial cells:
Primary sex cords: Testis cords (middle) + rete testis (end)
Rete testes + mesonephric remnants: Efferent ductules
Mesenchymal thickening: Tunica albuginea
Mesothelial cells: Sertoli and Leydig Cells
Disorders of Sex Development:
Primordial germs cells do not form/migratePatient is female
Gonadal agenesis
Disorders of Sex Development:
One testis, one ovary, external genitalia of both sexes
True hermaphroditism
Disorders of Sex Development:
46XY
Ambiguous external genitalia until puberty
Deficiency of DHT
5a-reductase type 2 deficiency
Adult Derivatives of the Mesonephric Ducts, Male
SEED Seminal vesicles Epipdydymis Ejaculatory Duct Ductus Deferens
Adult Derivatives of the Mesonephric Ducts, Female
Appendix of vesiculosis
Gartner’s Duct
Adult Derivatives of the Paramesonephric Ducts, Female
FUUH Fallopian tubes Uterus and Cervix Upper 1/4 of vagina Hydatid of Morgagni
Congenital Malformations
Diagnosis of Cryptorchidism is made after how many months of undescended testis
3-6 months
Congenital Malformations
Most common penile anomaly
Pathogenesis?
Hypospadias
Failure of the closure of the urogenital sinus
OOgonia
What phase from before birth until puberty?
Until ovulation?
At fertilization?
Meiosis 1 prophase
Meiosis 2 metaphase with formation of 1st polar body
Completion of Meiotic division with formation of 2nd polar body
Female Pelvic Ligaments
Suspensory ovarian ligaments
Connects ovary to lateral wall
Contains ovarian vessels
Female Pelvic Ligaments
Ovarian round ligament
Ovary to uterus
Female Pelvic Ligaments
Broad ligament
Uterus, fallopian tubes, and ovaries to lateral pelvic wall
Female Pelvic Ligaments
Cardinal ligament of Mackenrodt
Connects cervix to lateral pelvic wall
Major support to uterus and cervix
Female Pelvic Ligaments
Uterine round ligament
Uterus to labia majora via the inguinal canal
Contains the artery of Sampson
Maintains anteversion during pregnancy
Congenital Malformations
Mayer-Rokitansky-Kuster-Hauser Syndrome
Mullerian agenesis
2nd most common cause of primary amenorrhea
Tx: Mackendow procedure
Congenital Malformations
Uterus Didelphys
2 hemiuterus, 2 cervix
Congenital Malformations
Most common Mullerian duct abnormality
Septate uterus
Most common cause of 2nd trimester abortion
Female Anatomy:
Define vulva
All structures visible externally from the pubis to the perineal body
Female Anatomy:
What are the contents of the vestibule?
HymenVaginal openingUrethral openingPeriurethral glands (Skenes glands)Vulvovaginal glands (Bartholin glands)
Female Anatomy:
Differentiate labia majora and minora
Majora: KSSE (outer), NKSSE (inner) (+) hair follicles, sweat glands, Montgomery glands
Minora: NKSSE, (-) hair follicles, sweat glands
Pathology of the Skenes glands (particularly if menopausal)
Urethral diverticulum
Sx: recurrent UTI
Tx: Treat UTI and resect
Pathology of the Bartholins glands
Bartholin’s cyst / Abscess
Tx: marsupialization
Female Anatomy:
Area of paucity in the vagina
Upper & middle third
Area where tampons can be forgotten
Female Anatomy:
Vaginal length
Ant: 6-8 cm
Post 7-10 cm
Female Anatomy:
Blood supply of the Vagina?
Upper: Cervico-vaginal branch of the uterine art
Middle: Inferior vesical arteries
Lower: Middle rectal & Int. Pudendal art
Venous drainage: Vaginal plexus drains into int. iliac vein.
Fallopian Tube:
What are the 4 segments?
Intramural: within uterus muscular wall
Isthmus: narrowest portion
Ampulla: widest and most tortous
Infundibulum: (+) fimbriae
Adult Derivatives of the Paramesonephric Ducts, Male
Appendix of the testes
Ectopic pregnancy rates within the Fallopian tubes
80% ampulla
12% isthmus
~5% intramural
~1-2% interstitial
Ovary: Attaches the ovary to the broad ligament
Mesovarium
Note: the ovary is not covered by peritoneum
Ovary: Layers of the ovary
Cortex:
Germinal Epithelium of Waldeyer / Surface epithelium
Tunica albuginea
Primordial and Graafian follicles
Medulla: Loose connective tissue Smooth muscles Stroma and blood vessels Few to No follicles
Nerve injuries during obstetric procedures
Radical hysterectomy
Genitofemoral nerve & obturator nerve
Nerve injuries during obstetric procedures
Improper dorsal lithotomy position
Peroneal nerve
Fallopian tube:Longest fimbriae
Fimbria ovarica
Nerve injuries during obstetric procedures
Inguinal node dissection
Femoral nerve
Complication during node dissection of the obturator fossa
Ext. iliac artery
Bony Pelvis:
Boundaries
Superior: pelvic inletInferior: pelvic outletAnt: Pubic bones, ascending rami, obturator foraminaLat: ischial bones and sacrosciatic notch
Complication due to straddle / anesthesia for the second stage of labor
Pudendal artery damage
Diameters of the Pelvic Inlet Transverse: Oblique: Post Sagittal: AP:
Transverse: 13 cm Oblique: 13 cm Post. Sagittal: 4 cm True conjugate: 11 cm Obstetrical conjugate: 10 cm Diagonal conjugate: >11.5 cm - only one measured clinically.
Signs of a contracted midpelvis
Prominent ischial spine
Convergent sidewalls
Shallow sacrum
Narrow sacroiliac notch
Laxity of the pelvic joints
Due to hormonal changes during pregnancyEsp. affects the symphysis pubisIncreases mobility of sacroiliac joint
How is the midpelvis measured? Pelvic outlet?
Midpelvis: at the level of the ischial spines
Outlet: intertuberous diameter
Ischial spines as a landmark:
1) Plane of least pelvic dimensions
2) Levator ani muscle at this level
3) Engagement at this level
4) IR of head when occiput
5) Mid forceps, low if beyond this
6) Pudendal nerve block
7) Normal external cervical os
8) Location for ring pessary for pelvic organ prolapse
Pelvis types:
Most to least common type
Gynecoid
Anthropoid
Android
Platypelloid
Pelvis type:
Prone to Deep transverse arrest
Android (with worst prognosis)
Pelvis type:
Prone to face delivery
Anthropoid
Pelvis type:
Poor prognosis for vaginal delivery
Android
Platypelloid
Pelvis typesMost to least common type
Gynecoid
Anthropoid
Android
Platypelloid
Pelvis type:Prone to face delivery
Anthropoid
Follicular Phase Goal
Restore endometrium, prepare for pregnancy
Follicular Phase
Theca Cell
LH stimulation
Desmolase active (cholesterol to pregnenolone)
Androgens produced
Follicular Phase
Granulosa Cell
FSH stimulation
Converts androgens to estrogen
Follicular Phase
Estrogen
Inhibits FSH and LH release
Increases Granulosa cell sensitivity to FSH
Initiate release of inhibin - allowing only 1 secondary follicle to develop
Uterine cells to increase rate of mitotic division
Cervical mucous : ferning (7th-18th day crystal arborization)
LH Surge
Triggers ovulation and follicular rupture in 12-24 hours
Cumulus-oocyte complex
Luteinization of Granulosa Cells
Resumption of oocyte maturation
Ovulation
~Day 14 of the cycle
Spinnbarkeit formation
What is Spinnbarkeit?
Egg white cervical mucous, stretches 6cm.
Post-Ovulatory Phase
Corpus Luteum?
Corpus Hemorrhagicum?
Luteum: granulosa + theca cells
Hemorrhagicum: mittelschmerz
Post-Ovulatory Phase
Progesterone
**Table in First Aid
Menstruation:
Most striking and constant event:
Period of vasoconstriction preceding menstruation.
Menstruation:
By what day has the endometrium been restored?
5th.
Urine Metabolites during the Menstrual cycle
Early follicular: low pro, inc est
Late follicular: low pro, rapid inc est
Luteal phase / pregnancy: progesterone
Preovulatory or Postovulatory?
Constant (14 days)
Postovulatory
Preovulatory or Postovulatory?
Low basal temp
Preovulatory
Preovulatory or Postovulatory?
Thin and watery cervical mucous
Preovulatory
Preovulatory or Postovulatory?
Dominant hormone: estrogen
Preovulatory
Endometrium of pregnancy?
What are its layers?
Decidua Basalis, Capsularis, Parietalis
Later, the capsularis and parietalis fuse to become the Decidua vera
Decidua Basalis
Implantation site
Decidua capsularis
Overlies the enlarging blastocyst
More prominent during the 2nd month of pregnancy, eventually fuses with parietalis
Decidua parietalis
Remainder of the uterus
Key event in fertilization allowing the sperm to penetrate the zona pellucida
Acrosome reaction
Cycle day: 22-24
Predecidual reaction (ready for zygote implantation)
Earliest histologic sign of progesterone action
Basal vacuolation
Postconception: Week 1
Cleavage
Blastocyst
Implantation
Postconception: Week 2
Embryoblast differentiated
Trophoblast differentiated
Differences between syncytiotrophoblast and cytotrophoblast?
Cytotrophoblast: divides mitotically
Syncytiotrophoblast: produces HCG
Postconception: Weeks 3-8
Gastrulation
Period of high susceptibility to teratogens
Formation of Organs/Limbs
CNS: first to develop, continues postnatally
Heart: completed by 8 weeks
Upper limb: completed by 8 weeks
Lower limb: completed by 8 weeks
Ext. Genitalia: differentiated by 12 weeks
Amniotic fluid, by the numbers
12 weeks: 60 mL
34-36 weeks: 1 L
Term: 840 mL
42 weeks: 540 mL
Production and Regulation of Amniotic fluid
Production: amniotic epithelium, fetal kidneys
Regulation: fetal swallowing, fetal aspiration, exchange between skin and fetal membranes
Placenta at Term, by the numbers
450-500g
15-20 irregularly shaped and sized cotyledons
Fetal Development:
Embryonic period
3rd week after ovulation until 8th week AOG
Fetal Development:
Abortus
20 weeks or less
Birth weight < 500g
Fetal Development:
Week 12
Uterus becomes an abdominal organ
(+) breathing movements
Fetal Development:
Week 14
Gender can be identified by experienced examiners
Fetal Development:
Week 16
(+) quickening
Fetal Development:
Week 20
(+) vernix caseosa
Lanugo covers the whole body
Fetal Development:
Week 28
Starts eye opening
90% chance of survival
Fetal Development:
Week 32
Testis descend
Fetal Development:
Week 34
Mature hair appears
Fetal Development:
Week 36
More rotund body, (+) fat deposition
Fetal Development:
Week 40
Testes in inguinal canal / scrotum
Determining Fetal Age by UTZ
1st trim: CRL
2nd trim: BPD / FL
3rd trim: BPD
Head Circumference
Smallest?
Greatest?
Smallest: sub-occipitobregmatic (32 cm)
Greatest: Occipitofrontal (34.5 cm)
Head Diameters
Greatest transverse
Bitemporal (8.0 cm)
BPD (9.5 cm) - greatest transverse
Occipitomental (12.5 cm)
Fetal circulatory shunts
Ductus venosus -> ligamentum venosum
Foramen ovale -> closes
Ductus arteriosus -> fxn closed 10-12 hours post birth, anat closed 2-3 weeks
Fetal Hematopoeisis
Embryonic period: yolk sac
2nd trim: Liver & spleen = Hemoglobin F
3rd trim: Bone marrow (starts at 4months AOG) persists until adulthood.
Test for fetomaternal hemorrhage
Kleihauer-Betke Test
Fetal RBCs are resistant to denaturing effects of alkali - adult RBCs become ghosts.
Surfactant
Produced by type 2 pneumoncytes
As early as 28 weeks but a sufficient amount is present only at 34-36 weeks.
When does alveolar development complete?
8 years of age
Hormones of Pregnancy:
HCG
Produced by syncytiotrophoblast
Plasma within 7-9 days of fertilization
Doubles every 1.4-2 days, max level around 8-10 weeks
Nadir at 18-20 weeks
Hormone of pregnancy that:
Rescues the corpus luteum
promotes male sexual differentiation
Promotes secretion of relaxin (vascular vasodilation and myometrial smooth muscle relaxation)
HCG
Hormone of pregnancy that:
Prolactin and growth hormone like activity
Diabetogenic
HPL / Chorionic somatomammotropin
Hormone of pregnancy that:
Ensures uterine quiesence during pregnancy
Inhibits T-lymphocyte mediated tissue rejection
Progesterone
Hormone of pregnancy that:
Is produced from the fetal adrenals
DHEAS - processed into estriol
Hormone of pregnancy that:
Dominates during week 1- week 6 of gestation
Estradiol
Maternal Adaptation to Pregnancy
Softening of and compressibility of the isthmus occurring in the 6th-8th week AOG.
Hegar’s sign
Maternal Adaptation to Pregnancy
Softening of the cervix from 6th-8th week AOG
Goodell’s sign
Maternal Adaptation to Pregnancy
Edema and engorgement of vasculature: bluish discoloration at 6 weeks AOG
Chadwick’s sign
Maternal Adaptation to Pregnancy
Changes in Skin
MSH: linea nigra, chloasma
Hyperestrogenemia: spider nevi
Corticosteroids: striae
Maternal Adaptation to Pregnancy
Cardiac Changes
HR: Inc 10bpm
Volume: Inc 40-45%
CO: significant increase 30-40% (if patient is supine, decreased by 20%)
BP: no change in systolic, decreased diastolic
Heart displaced upwards and to the left
Maternal Adaptation to Pregnancy
Genito-urinary changes
Urinary stasis due to increased peristalsis
Asymptomatic bacteruria
Nocturia
Maternal Adaptation to Pregnancy
Renal changes
Kidneys hypertrophy
GFR inc by 50%
Inc: GRF, RPF, Crea Cl.
Dec. BUN, Crea, Uric acid
Maternal Adaptation to Pregnancy
Physiologic Hydroureter
Estrogen: hypertrophy and muscle elongation
Progesterone: atony
Right > Left
Maternal Adaptation to Pregnancy
GI Changes
Appendix displaced upward and viscerally
Dec: GIT motility, LES tone, CCK (gallbladder stasis)
Inc: Water absorption
Inhibited intraductal transmission of bile acid = Pruritus gravidarum, Intrahepatic cholestasis
Maternal Adaptation to Pregnancy
Hematologic
Hemoglobin: 12.5, Anemia: 11
Hematocrit: decreased
Decreased platelet count
Slightly hypercoagulable
All coag factors increased except 11 and 13
Maternal Adaptation to Pregnancy
Endocrine
Pituitary gland enlarges 135% (-) increase in blood supply
Adrenal hyperplasia,
Inc: cortisol (most bound to transcortin), aldosterone, deoxycorticosterone, testosterone
Thyroid: increased production (40-100%), but still euthyroid
Parathyroid: PTH: Decrease 1st trim, increase during the rest; Calcitonin: increased
Ovaries at rest
Maternal Adaptation to Pregnancy
Pulmo
RR unchanged
Inc: TV and resting minute ventilation
Dec: FRC and RV (Diaphragm elevates ~4cm during pregnancy)
Maternal Adaptation to Pregnancy
Weight gain
12.5kg or 27.5lbs BMR inc 10-20% "convention" 1st trim: 2lbs 2nd: 11lbs 3rd: 11 lbs
Maternal Adaptation to Pregnancy
Immunologic
Suppressed T helper Cells (Th4) Increased Th8 PMN leukocyte chemotaxis decreased Increased leukocytes Increase in cervical IgA and IgG
Maternal Adaptation to Pregnancy
Eyes
Decreased IOP
Corneal sensitivity
Maternal Adaptation to Pregnancy
CNS
Attention, concentration and memory problems
Maternal Adaptation to Pregnancy
Skeletal
Progressive lordosis
Increased pelvic joint mobility
FDA Classification of Drugs for Pregnancy
A: Ayos sa fetus! B: Bad sa hayop C: Culang [sic] sa pag-aaral D: Desperate measures (benefit>risk) X: X_X