Obstetrical Complications Flashcards
definition of preterm birth?
-occurs after 20 weeks but before 37 completed weeks of gestation
what are the four main pathways that we use to prevent PTL?
- Infection
- placental-vascular
- psychosocial stress and work strain
- uterine stretch
which abx do we treat women in preterm labor with?
-treat for group B strep
relative risk for PTL increases as ______ decreases?
- cervical length
- use that and fetal fibronectin as screening tools
diagnosis of PTL
- between 20 and 37 weeks gestation
- must have: 1.) uterine contractions, 2.) cervical change (dilation of 2 cm or 80% effacement)
how do we initially manage PTL?
hydration and bed rest will resolve contractions in about 20 % of patients
- culture for Group B strep
- fetal ultrasound
What do we do if there is no response to IV hydration and rest?
- begin tocolysis
- MgSO4
- Nifedipine
- PG synthetase inhibitors (indomethacin)
What does MgSO4 do?
- competes with Ca2+ for entry into cell at time of depolarization
- IV
NIfedipine
- Oral
- inhibits slow, inward current of calcium during second phase of the action potential
- suppresses PTL
Prostaglandin synthetase inhibitors
- Pg’s usually induce myometrial contractions… so we stop it
- Indomethacin is used
- maybe oligohydramnios
- greater risk of necrotizing enterocolitis for infant
what do we give to make the fetal lungs mature a little more?
- Betamethasone
- between 34 and 36 weeks at risk of preterm birth within 7 days
- have not received a previous course of antenatal corticosteroids
What mechanical thing is used in women with a shortened cervix to help prevent PTL?
-Arabin pessary
What is Premature rupture of membranes (PROM)?
-premature rupture of the membranes before the onset of labor at any gestational age
PROM diagnosis
- based on history
- loss of fluid
- confirmation of amniotic fluid in vagina
***What do we NOT do is we think there is a preterm infant in there with a presumed ruptrured membrane?
- Do NOT check the cervix
- it increases risk of infection especially with the prolonged latency before delivery
- rupture is confirmed using a sterile speculum
what will we see if there is PROM?
- pooling
- nitrazine paper turns blue
- ferning
What is PPROM?
-preterm premature rupture of membranes
What is the main goal of PPROM management?
-to continue preggo until lung profile is mature
What does ACOG recommend that we do for PPROM antibiotic usage?
-48 hour course of IV Ampicillin and Erythromycin/azithromycin followed by 5 days of Amoxil and Erythromycin
How long do we want to keep the baby in there at lesat to reduce the risk of RDS?
-34 weeks
What cells in the fetus produce surfactant?
-type 2 pneumocytes
What do we want the L/S ratio to be for fetal lungs?
- greater that 2
- Lecithin/Sphingomyelin
What means that the fetal lung is mature if it’s there?
-Phosphatyidyl glycerol (PG)
What is the rapid test for fetal lung maturity?
-the Lamellar body number density assessment (LBND)
definition of Intrauterine growth restriction (IUGR)?
-when the birth weight of a newborn is below the 10% for a given gestational age
What are the 3 main categories of IUGR with regard to etiology?
- maternal
- placental
- fetal
what are some maternal causes of IUGR?
- ciggs
- alcoholism
- Anti phospholipid syndrome
Placental causes of IUGR?
- defective trophoblast invasion
- diabetes
- placental or cord abnormalities
Fetal causes of IUGR?
- inadequate or altered substrate
- TORCH
- multiple gestations
What is the main thing for IUGR diagnosis?
-Ultrasound
What is used as a primary screening tool for IUGR?
-serial fundal height measurement
When do we order an ultrasound for IUGR?
-if the fundal height lags more than 3 cm behind the gestational age
What is the main goal in the management of IUGR?
-deliver before fetal compromis but after fetal lung maturity
What is the key thing with doppler study of the umbilical artery?
- the Umbilical flow velocity waveform of normally growing feuses is characterized by high-velocity diastolic flow
- with IUGR, there is diminution of umbilical artery diastolic flow
What should we do if we suspect an IUGR?
- do an ultrasound.. if normal, no intervention
- if >38-39 weeks, then deliver
- if less, begin antenatal testing
- if normal, continue pregnancy, if not, deliver
What is the definition for post-term pregnancy?
-past 42 weeks
-perinatal mortality is higher
-
What do we end up doing for management of postterm preggo?
-induce labor!
definition of IUFD
-fetal death after 20 weeks gestation but before the onset of labor
When do we suspect IUFD?
- if patient complains of absence of fetal movements or it unable to Doppler fetal heart tones
- confirm by ultrasound with lack of fetal activity and absence of fetal cardiac activity
What are the patient with IUFD at risk of?
- DIC
- need CBC, fibrinogen level, PT/PTT/INR
What do we do for follow up for the IUFD?
- search for cause: TORCH, listeria… etc
- the later preggos will have greater risk, so give them antenatal testing
