Placenta Flashcards
Human placenta is .?
Discoid - Disc Shaped
Deciduate - Sheds off after Delivery
Hemochorial - Lies in contact with Maternal Blood
Deciduate -?
Sheds off after Delivery
Hemochorial ?
Lies in contact with Maternal Blood.
Weight of placenta at term.?
500 gms
Wgt of placenta = Weight of Fetus at what week.?
17 wks
Hofbauer cell..? where .?
Placenta.
Zika Virus can Affect this.
PEG cells .. Where.?
FT.
Langerhan Cells.. Where.?
Cytotrophoblast.
Nitabuch Layer.. Where.?
Btw Chorion and Decidua.
Primary Villi.?
Secondary Villi.?
Tertiary Villi.?
Trophoblastic Shell .
Mesodermal Core.
Vascular.
Placental membrane barrier..
From Outside to inside.
Syncytiotrophoblast-Trophoblast-Extraembryonic Mesoderm- Fetal Capillary Endothelium
Uteroplacental Blood Flow at term.?
500-750 ml / min
Uterine Blood Flow at term.?
750 ml / min
Fetal Blood flow at term.?
125ml / kg
Rate of Oxygen Delivery at birth.?
8ml /kg/min
Fetoplacental Blood flow at term.?
400ml/min
Which vessel carries oxygenated blood to Fetus.?
Umbilical Vein
O2 saturation- 70-80%
Remnant of Umbilical vein.
Ligamentum Teres
Remnant of Umbilical Artery
Medial umbilical ligament.
Lateral umbilical Ligament is a remnant of .?
Inferior epigastric artery
Urachus forms.?
Median Umbilical Ligament.
Functional unit of Placenta.?
Cotyledons.
USG for Localization of placenta is done in.?
Third trimester.
Placentomegaly..
Thickness above 4 cms.
Thickness of placenta at term.?
2.5 cms.
at 40 wks = 4 cms.
Maternal Causes of Placentomegaly.
Diabetes
Severe Anemia
Alpha Thalasemia
Fetal Causes of Placentomegaly.
Hydrops Fetalis.
Infections like Syphilis and Torch.
Triploidy.
Battledore Placenta.
Cord attached to the edge or Margin of Placenta or Marginal Insertion of the Cord.
Normally attached to the middle.
Extrachorial Placenta.
Maternal Side bigger than Fetal Side
Forms Ring.
Can lead to IUGR or APH
Types Of ExtraChorial Placenta.?
Circumvallate - Valve Like Thickening.
Circummarginate - Smooth.
Succenturiate Placenta.
Two unequal lobes connected by Blood vessels.
Placenta Spuria.
Two unequal Lobes no connecting blood vessels.
Placenta Bilobata.
Two Equal Lobes With Blood Vessels connecting them.
Placenta Bipartite
Bilobata.
Placenta Duplex
Bilobata.
Mx of Succenturiate or spuria or bilobata.
Curettage.
Complication of Succenturiate or spuria or bilobata.
Secondary PPH.
After 24 hrs within 12 weeks post delivery.
MCC of Asherman Syndrome.
Curettage.
Fenestrated Placenta.
Central portion of Discoidal Placenta is missing.
Missing Chorionic plate and villi.
Placenta Membranacea.
Thin placenta where all fetal membrane is covered by villi.
Leads to serious hemorrhage due to Placenta Previa or accreta..
Morbidly Adherent placenta.
Absent nitabuch’s layer.
Deep penetration of blastocyst.
Types of Morbidly Adherent Placenta.
P. Accreta.
P. Increta.
P. Percreta.
P. Accreta.
Superficially Attached to Myometrium.
P. Increta.
Deep Inside Myometrium.
P. Percreta.
Chorionic Villi Attached to Serosa.
Pathogenesis of Morbidly Adherent Placenta.
Absent nitabuch’s layer and Decidua Basalis.
Clinical Presentation of Refractory PPH - Suspect
Think Morbidly adherent placentas.
Risk Factor for Morbidly adherent placenta.
Placenta previa.
Previous LSCS.
H/O Curettage or uterine surgery.
IOC for diagnosing Morbidly Adherent Placenta.
USG
USG finding for Morbidly Adherent placenta.
Absence of Subplacental Shadow which represents D. Basalis.
Heterogeneous appearance of placenta.
Placental Lakes.
Gold Standard for Morbidly Adherent Placenta.
MRI.
Mx of Morbidly Adherent Placenta.
Elective CS + Hysterectomy.
But upper segment CS .
Do Hysterectomy to avoid Refractory PPH. if Pt refuses clear as much placenta as possible and give MTX to prevent Gestational Trophoblastic neoplasia.
Hormones produced by Placenta
Progesterone - from 8 wks
Estrogen.
HCG
HPL- Human Placental Lactogen.
Luteal Placental Shift.
Functional shift from Luteum to Placenta.
Lifespan of Corpus Luteum
10-12 wks
Precursor of Progestrone.
Maternal LDL and Cholestrol.
Decidual reaction.
Glands become Hypersecretory and stroma becomes edematous and rich in glycogen.
Arias- Stella Reaction.
Glands become hypersecretory and there are changes in nucleus.
Arias Stella Reaction is seen in
Intrauterine, Molar, and Ectopic Pregnancy.
Enzyme required for Estrogen Synthesis.
17-OH-Hydroxylase.
Req for Conversion of 17-OH progesterone to Androstenedione. A c21 steroid req for estrogen synthesis
Estrogen in Pregnancy.
Fetal ACTH converts DHEA-S to E2 by Sulphatase and Aromatase.
Most Common Estrogen in pregnancy
E2
Most Specific Estrogen in Pregnancy
E3
role of E in Pregnancy
At term causes uterine contraction.
Inc E is seen in
Conditions with Inc Placental Tissue.
Erythroblastosis Fetalis`
Dec E is seen in
Absent or Hypoplastic Adrenal glands - Anencephaly
Deficiency of Aromatase and Sulphatase.
Down’s Syndrome - Low levels of C19 steroids.
C-19 Steroid
DHEA-S and Androstenedione.
C-21 Steroid
17-OH Progesterone
Main Site of HCG prod.
Syncytiotrophoblast.
Hormone with Max glycogen Content.
HCG
Hormones with alpha and beta subunits
HCG, LH, FSH and TSH.
HCG is Structurally similar to
LH, FSH and TSH.
HCG is Functionally similar to
LH
Low levels of E can lead to
Post term pregnancy due to Inability to start contractions.
When is HCG detected in blood.
8 days after fertilisation
5-6 days before period.
Most sensitive test to detect HSG
FIA > RIA
Level of HCG.
1) Early preg.
2) Max at.
3) Min at
1) Nearly Doubles every 48 hrs.
2) Max at 10 wks. 50k-10*5 IU
3) Min at 16 wks.
T half of HCG
36 Hrs.
HCG becomes normal.?
2 wks after delivery.
4 wks after abortion.
Functions of HCG- 3
Supports Corpus luteum
Initial stimulus for Prod of Testosterone from leydig cells.
Prevents rejection of Fetus
Very High levels of HCG seen in
Twin, Molar, Choriocarcinoma, Down’s, Erythroblastosis fetalis.
Dec Levels of HCG is seen in
Ectopic, All trisomies expt down’s, Abortion.
UPT.
Sandwich elisa test.
min detection level 20 IU/L
Critical Titre of HCG
Value which confirms Intrauterine Pregnancy with a visible gestational sac.
TVS- 1500 IU/L
TAS- >5000 IU/L
HPL aka
Human Chorionic somatotropin.
Marker for checking Placental functioning
HPL or HCS
Max HPL at
36 wks.
Hormone that is produced max at term is
HPL at 1g/dl
t half of LH
2 hrs
t half of HPL
30 mins
Hormone that brings about insulin resistance in mother
HPL
Functions of HPL
1) Lipolysis in mother- inc FA- Which provides energy for mother and glucose sparing for fetus.
2) Insulin resistance in mother.
Hormone not responsible for insulin resistance in mothers
HCG
4 layers of Fetal membrane
Chorion
Amnion
Yolk Sac
Allantois.
Fetal membrane layer with most tensile strength
Amnion
Avascular fetal membrane layer
Amnion
Site for hematopoeisis
Yolk Sac
Allantois.
Diverticulum derived from hind gut and grows in connecting stalk.
PG Prevalent in Fetal membranes -
PGE2 -
PGE2 function at labour
Accelerates labour.
Umbilical cord is derived from.
Connecting Stalk.
Short cord.
< 30 cms
Connective tissue of cord
Wharton’s jelly
Coils of cord is called as
Folds of Hobokon
Which Umbilical vein disappears
Right UV
MC vascular anomaly of the cord.
Single Uterine Artery.
Single Uterine Artery indication.
MC in diabetic and twins
Significant finding.
inc chances of renal and cvs malformations.
Malformations and Single Umbilical artery is seen in
Trisomy.
Velamentous cord insertion.
Cord attaches to fetal membrane before insertion into placenta.
Vasa Previa.
Rupture of blood vessels leading to fetal blood loss.`
How to diff btw vasa and placenta previa.
Singers Alkali Denaturation test.
HbF and HbA which is resistant to alkali and acid.
HbF resistant to Acid.
HbA sensitive to Acid.
Reagent in APT test.
NaOH or KOH.
Mx of Vasa Previa.
LSCS.
Hyrtil’s anastomosis.
Connection of 2 umbilical artery before insertion into cord.
