Things Flashcards
US findings diagnostic of pregnancy failure
- CRL 7mm, or more, and no heartbeat
- Mean sac diameter of 25mm, or more, and no embryo
- No embryo with a heartbeat 14 days or more after a scan that showed a gestational sac without a yolk sac
- No embryo with a heartbeat 11 days after a scan that showed a gestational sac with a yolk sac
US findings suspicious for, but not diagnostic of, pregnancy failure
- CRL less than 7mm and no heartbeat
- Mean sac diameter of 16-24mm and no embryo
- No embryo with a heartbeat 7-13 days after a scan that showed a gestational sac without a yolk sac
- No embryo with a heartbeat 7-10 days after a scan that showed a gestational sac with a yolk sac
- Empty amnion (amnion seen adjacent to yolk sac, with no visible embryo)
- Enlarged yolk sac (greater than 7mm)
- Small gestational sac in relation to the size of the embryo (less than 5mm difference between mean sac diameter and CRL)
What criteria is used to be able to consider medical management of early pregnancy loss?
Women without - infection - hemorrhage - severe anemia - bleeding disorders Women who want to shorten time to complete expulsion but want to avoid surgery
Stillbirth risk factors
Non-Hispanic black race Nulliparity (increased rate at extremes of parity- >3 prior pregnancies) Advanced maternal age Obesity Pre-existing diabetes Chronic hypertension Smoking Alcohol use Use of ART (assisted reproductive technology) Multiple gestations Male fetal sex Unmarried status Past OB history - hx stillbirth - hx preterm delivery - hx FGR (highest risk with Hx FGR delivered <32wk) - hx Pre-E
How do you describe Fetal Kick Counts?
One method is to write down how long it takes the fetus to make 10 movements each day.
To do this choose a time when the fetus is usually active. (After eating)
Each baby has its own level of activity and most have a sleep cycle of 20-40 min.
Alert your doctor if there is a change from the normal pattern or number of movements.
- ACOG patient eduction pamphlet
10 movement in 2 hours
Start @ 28wk?
Lack of evidence to support fetal kick counts
Type of Antepartum Tests for fetal well being
Fetal kick count NST (Vibroaccoustic stimulation) Oxytocin challenge test or Contraction stress test Biophysical Profile Modified BPP Doppler studies
Causes of baseline abnormalities:
Bradycardia
Fetal distress Cord compression Heart block Maternal hypothermia Maternal drug
Causes of baseline abnormalities:
Tachycardia
Maternal Pyrexia Thyrotoxicosis Maternal acidosis &/or ketosis Hypoxia Fetal cardiac anomaly (SVT)
Describe FHR variability
Determined over a 10 min period
Fluctuations in baseline of IRREGULAR amplitude and frequency
(Regular would be sinusoidal)
Causes of decreased FHR variability
Fetal sleep state Hypoxia or fetal metabolic acidosis (pH <7 & base deficit =/> 12 mmol/L) Prematurity Neurologic problem Certain fetal anomalies Medications - Mag sulfate - General anesthesia - Narcotic - Barbiturates - Tranquilizers
Causes of Sinusoidal FHRs
Fetal anemia (any etiology) - Rh isoimmunization - Parvo virus infection w/ anemia - Anemia due to fetomaternal hemorrhage Medications - Narcotics
Fetal Arrhythmias
Audible arrhythmias: interment or skipped beats.
- 95% will spontaneously resolve if there are no cardiac anomalies
Most common: Atrial PAC –> SVT (220-240bpm) followed by atrial fibrillation or flutter
- Fetal arrhythmia >200bpm
- Complete heart block 50-70bpm
- SLE or Sjorgens syndrome with antibodies (Anti-Ro or Anti-La)
FHT reactivity based on gestational age
24-28wk: 50% (28 75%)
28-32: 85%
34wk: 95%
Early Deceleration
Nadir at the same time as peak of contraction
May signify head compression - increase parasympathetic output from fetal brain to fetal SA node
Late Decelerations
Nadir after the peak of contraction
May signify utero-placenta insufficiency
What is an adequate Contraction Stress Test
Need at least 3 contractions, of moderate intensity, in 10 min, lasting 40-60 seconds
Need to observe pt until uterine activity return to baseline
Contraction Stress Test Interpretation
- Negative: No late or significant variable decels
- Positive: late decels after >50% of contractions (even if contraction frequency is < 3 in 10 min)
- Equivocal-Suspicious: intermittent late )<50%) decels or significant variable decels
- Equivocal: decels with contractions that are more frequent than every 2 min or lasting longer than 90 seconds
- Unsatisfactory: less than 3 contractions in 10 min or an uninterpretable tracing
Contraindications to CST
PB: any condition that is contraindicated to labor or vaginal delivery
ABC Video: PPROM/PROM Previa Multiple gestation Preterm labor Hx classical CS or uterine surgery involving myometrium
Components of BPP
- NST reactive
- Fetal movement: 3 discrete body or limb movements in 30 min
- Fetal tone: 1 extension/flexion of extremity, opening/closing hand
- Fetal breathing: 30 sec in 30 min
- Normal amniotic fluid volume: vertical pocket =/>2
Ultrasound findings consistent with placenta accreeta specrum
- Placental lacunae at 15-20 weeks
- Thinning of myometrium at placental site
- loss of retroplacental clear space
- Increased vascularity of the uterine serosa-bladder interface
Hypothesis of the etiology of placenta accreta spectrum
A defect in the endometrial-myometrial interface leads to failure of normal decidualization in the area of the uterine scar, which allows for abnormally deep placental anchoring villi and trophoblast infiltration
Definition of placenta accreta
abnormal trophoblast invasion into the uterine myometrium
