Placental development
Blastocyst at day 6, invaded endometrium
outer later called trophoblast that makes contact with endometrium and covers entire placenta. Becoming the barrier between mother and fetus.
Umbilical cord
contains 2 arteries 1 vein (if question with child with a single artery search for a congenital anomaly) more common in twin pregnancy’s
Conditions associated with single umbilical artery
- Trisomy 18
- Renal anomalies
- Cardiac anomalies
- Twins
Chorioamnionitis
intrauterine inflammation/infection. Clinical diagnosis characterized by maternal fever with one or more of the following:
- Maternal leukocytosis >15k
- Fetal tachycardia >160
- pus from cervical os
- biochemical or microbiological evidence of amniotic fluid infection
often follows prolonged ROM >18hrs which greatly increases risk of early onset neonatal sepsis most commonly GBS, E. Coli
Placental abnormalities
Placenta acreeta- placental vili attach to myometrium of uterus usually due to previous injury (curettage, myomectomy, cs)
increta- vili invade the uterine myometrium
percreta- vili penetrate through myometrium and uterine serosa, can result in hemorrhage
abruption - premature placental detachment, medical emergency
chorioangiomas- benign placental tumors that can become large and interfere with fetal circulation
Multiple gestations
placenta provides clue into type of twins. Chorionic refers to placenta, amniotic refers to the sac surrounding each fetus
- Dichorionic/Diamniotic- 2 placentas, 2 sacs cleavage day 1-3
- Monochorionic/Diamniotic- 1 placenta, 2 sacs cleavage day 4-8
- Monochorionic/Monoamniotic- 1 placenta, 1 sac cleavage day 8-13
- Conjoined cleavage day >13
Most commonly monochorionic are identical and dichorionic are fraternal although dichorionic can also be identical depending on time of cleavage
