Presentation (19).pptx..................

.

1. PLACENTAL INSUFFICIENCY Name: SHUBHANGI GARG GROUP: 1427

2. PLACENTAL STRUCTURE AND CIRCULATION Chorionic villi provide a large surface area for maternal- fetal exchange. Spiral arteries (maternal) fill the intervillous spaces in the decidua basalis layer of the endometrium: 1.Bring in oxygenated blood for the fetus 2. The spiral arteries “rupture” and become large spaces called lacunae, which are extremely low-resistance areas and do not have the ability to regulate blood flow through the organ

3. 2 umbilical arteries bring deoxygenated blood from the fetus to the placental chorionic villi. Exchange of gases and molecules occurs between the fetal blood in the chorionic villi and maternal blood in the lacunae, across the placental barrier. Fetal hemoglobin has ↑ affinity for O compared with maternal hemoglobin → causes O to move from maternal RBCs to fetal RBCs Umbilical vein transports oxygenated blood back to the fetus. Maternal veins carry deoxygenated blood back to the maternal circulation. Maternal and fetal blood never come into direct contact.

4. FUNCTIONS OF PLACENTA Gas exchange (O2and CO2 ) Nutrient exchange Fetal waste removal Hormone production (a fetal and maternal endocrine organ during pregnancy: HCG Human placental lactogen ( hPL )
Chorionic thyrotropin
Chorionic corticotropin -releasing hormone (CRH)
Progesterone Estrogens Glucocorticoids
Growth factors Metabolic functions to support the fetus: Glycogen and cholesterol synthesis Protein metabolism Assists in protection of the fetus from maternal immunologic rejection

5. Overview of normal and abnormal placental implantation Early fetal trophoblastic cells invade into the maternal decidua basalis layer of the endometrium: Trophoblastic cells should not invade into the myometrium beneath the endometrium. When trophoblastic cells do invade into the myometrium, the condition is called placenta accreta . Placentas typically implant in the fundal region of the uterus: The placental edge should be away from the internal cervical os .
When the placenta covers the internal cervical os , the condition is called placenta previa . When the placental edge is within 2 cm of the cervical os , it is called low-lying placenta. The placenta should remain connected to the maternal endometrium, providing O and nutrients, until after the delivery of the infant. When the placenta separates early, the condition is called placental abruption. When the placenta fails to provide adequate O or nutrients to the fetus, the condition is called placental insufficiency.

6. UTEROPLACENTAL INSUFFICIENCY Uteroplacental insufficiency may be acute or chronic and refers to the inability of the placenta to deliver a sufficient supply of O and nutrients to the fetus.

7. CHRONIC PLACENTAL INSUFFICIENCY Chronic uteroplacental insufficiency results in fetal growth restriction and associated complications. ETIOLOGY Maternal vascular disease, especially: hypertension Preeclampsia
Pregestational diabetes Severe maternal anemia Maternal smoking or cocaine use Uterine malformations

8. Ultrasound, demonstrating: Fetal growth restriction
Oligohydramnios (frequent) Increased vascular resistance within the placenta on Doppler studies Patients should be monitored antenatally with frequent nonstress tests and ultrasound to look for signs of fetal decompensation. Delivery is indicated when the fetus begins showing signs of distress (e.g., non-reassuring fetal status on testing). Typically, if patients are otherwise candidates for vaginal delivery, induction of labor is recommended over planned cesarean delivery, with close intrapartum monitoring. If preterm, give a course of steroids (typically IM betamethasone) to help promote fetal lung maturity prior to delivery. DIAGNOSIS MANAGEMENT

9. ACUTE PLACENTAL INSUFFICIENCY Periods of ischemia during labor contractions, preventing the delivery of O and nutrients at levels required to satisfy fetal requirements Note: Relative ischemia occurs during normal labor , but can be magnified with placental pathology.
Partial or complete placental abruption ETIOLOGY

10. DIAGNOSIS Via abnormalities noted on fetal cardiac monitoring: Recurrent late decelerations Persistent fetal bradycardia Uterus is frequently hypertonic and/or tachysystolic (> 5 contractions in 10 minutes). MANAGEMENT Intrauterine resuscitation techniques: Reposition the mother (may relieve vessel compression). Give mother IV fluids and O therapy to support her circulating O capacity. ↓ Uterotonics (e.g., pitocin ) and/or administer uterine tocolytics ( e.g.terbutaline ) Expedited delivery is indicated if infants fail to respond to resuscitation, via: Cesarean delivery (if remote from delivery) Operative vaginal delivery (e.g., forceps or vacuum extraction) if candidates are in the 2 nd stage of labor