ANTEPARTUM/ROUTINE OBSTETRICS Flashcards
Know what is done at each prenatal visit in the course of pregnancy
When is a ‘New OB’/first prenantal visit conducted in gestational age?
10-12 wga
In a New OB visit, what do we do in order to confirm pregnancy dating?
Ultrasound
What routine labs are performed in a NOB visit?
CBC
RPR
HIV
Hb electrophoresis
VZV
Rubella
GC/CT
Urine Culture
Hep B, C
Blood typing
Rh Status
Ab Screening
Aneuploidy Screening
Carrier Screening
When should Rh status be established?
With the first prenatal visit labs
What major diseases do we screen for carrier screening and when?
At the first prenatal visit (10-12 wga), we screen for CF and SMA
When do we conduct aneuploidy screening for the baby?
First prenatal visit labs
What vaccines do we recommend for the first prenatal/OB visit?
Influenza and COVID Vaccines
What do we look at in the second prental exam at 15-20 wga?
- Update H&P and problem list as appropriate
- FHR
- Anatomy Scan (18-22 wga)
- MSAFP maternal screen for alpha feto protein
When do we conduct the first anatomical ultrasound?
18-22 wga
What are we screening for with MSAFP?
MATERNAL SERUM ALPHA-FETOPROTEIN (MSAFP) The MSAFP screens for “open neural tube” defects. Open spina bifida (or “open spine”) and anencephaly are examples of open neural tube defects.
What does elevated AFP in pregnancy often indicate?
Neural tube and abdominal wall defects
What does decreased AFP in pregnancy be indicative of?
Trisomy 21 or 18
What is discussed in a 24 week prenatal visit?
- Update H&P and problem list as appropriate
- Fundal Height
- Labor pain management/contraception counseling (do you want an epidural or spinal? Do you want an IUD or nexplanon?)
What is done at a 28 wga visit?
- Update H&P and problem list as appropriate
- Fundal Height
- TDAP vaccine
- Rhogam if Rh negative
- CBC and 1 hr glucose screening
When do we normally conduct the 1 hr glucose screening?
If no hx of DM or GDM, then we do it at the 28 wga visit
When do we give Rhogam?
We give rhogam to an Rh negative mother at 28 weeks and after labor (within 72 hrs) and whenever there is an opprotunity for maternal fetal blood interaction such as with an amniocentesis, c-section, trauma, etc.
What is conducted at a 36 wga visit?
- update h&P as necessary
- Fundal height
- Fetal Presentation
- GBS
- For high risk pts, repeat HIV, Hep B, GC/CT, RPR (syph)
- Discuss Delivery timing as indicated (induction of labor, cessarian, etc)
What is conducted at a 38-41 wga visit?
- Update H&P as needed
- Fundal Height
- s/c induction as needed
When would we conduct GDM early?
For patients with BMI >25 or >23 in asian amerians AND one of the following:
-Physical inactivity
-first degree relative with DM
-AA, Latino, Native, Asian American, Pacific Islander
-Previous infant >4000g
-Previous GDM
-HTN
-PCOS
-HDL <35 or TAGs >250 or hx of CVD
-A1c>5.7, impaired glucose tolerance, or impaired fasting glycose
What A1c do we use as the threshold for early glucose intolerance testing?
over and equal to 5.7
What is considered an abnormal 1 hr glucose test?
greater than 130-140, cut off varies by institution (130, 135, and 140 are often the cut offs)
What criteria do we look at for a 3 hr glucose test?
We use either the carpenter-coustan or NDDG which have diff thresholds (NDDG has overall higher thresholds for what they consider glucose intolerant)
What are some clinical features to look out for when you suspect a mother with GDM?
She may present asymptomatically, efema, polyhydramnios, large for gestational age fetus (>90th percentile)
What is our first line approach to a mother with nausea and vomitting in pregnancy?
- Switch prenatal vitamins to folic acid supplementation only
- Ginger capsule 250 mcg 4x qd
- Consider p acupressure with wrist bands
If first line approach to nausea and vommitting fails, what pharmalogical option will we consider next?
Vitamin B6 (pyridoxine) alone or in combination with Doxylamine
What pharmalogical options can we consider if first line and vitB6 fail for nausea and vommiting in pregnancy?
Dimenhydrinate, Diphenhydramine, proclorperazine, promethazine
At how many wga can you do cell free DNA screening?
Minimum of 9 weeks
Why would cell free dna and placental cells from CVS show variation from the fetus/be incorrect?
Mosaicism
When can a dx of intrauterine fetal demise be given?
after 20 weeks gestation
A patient with an IUFD after 20 wga has what managment options?
- Expectant Managment: most women (80%) will pass the fetus within 8 weeks of fetal demise, most likely 2 weeks
- Induction of labor if desired, vaginal misoprostil or oxytocin infusion
- Vacuum aspiration
Note the D and C is not indicated because D and C is for first trimester pregnancy loss
What are the major signs of DIC in pregnancy?
Prolong Prothrombin time, low platelets, elevated creatinin from acute renal injury
Look for:
-Platelet Count: LOW
-Fibrin Markers: elevated
-Prothrombin time: elevated/prolonged
-Fibrinogen Levels: variable
Recall that DIC is a condition characterized by systemic activation of the clotting cascade, platelet consumption, and subsequent exhaustion of clotting factors that leads to widespread thrombosis and hemorrhage. Often associated with trauma, shock, and sepsis.
DIC SCORE CALCULATOR:
https://qxmd.com/calculate/calculator_649/dic-score
In retention of IUFD over 2 weeks, what leads to DIC in some patients?
The systemic absorption of thromboplastin produced by the placenta and deceased fetus
What are our main causes of antepartum hemmorhage after 20 wga?
Common causes of antepartum hemorrhage are bloody show associated with labor, placenta previa, and placental abruption.
Rare causes include vasa previa and uterine rupture.
What are major risk factors for placental abruption?
-Previous abruption
-htn
-trauma
-smoking
-Cocaine
-PROM
What are the major risk factors for placental previa?
-Previous placenta previa
-previous c-section
-Multiparity
-multiple gestation
-AMA
-Smoking
What are the risk factors for vasa previa?
-velamentous cord insertion
-placenta previa
-IVF
-Multiple gestations
What are the risk factors for uterine rupture?
-Previous c-section
-Transmyometrial surgery (full thickness myomectomy)
What will help you differentiate HELLP from AFLP?
Hypoglycemia (55–70 mg/dL ), leukocytosis (> 11,000/μL in adults), severe hyperbilirubinemia (Normal serum total bilirubin concentration is typically 0.1-1.0 mg/dL; normal serum direct bilirubin concentration is typically 0.0-0.3 mg/dL), and acute hepatic failure are more common in AFLP.
You will see hypertension and proteinuria moreso in HELLP.
If we are assessing someone for acute hepatic failure in pregnancy, what are we looking for?
The number one cause of acute hepatic failure in pregnancy is AFLP. So we should be looking for….
Features of acute hepatitis (RUQ pain, malaise, nausea, transminitis, hyperbilirubinemia)
Clinical signs of hepatic failure: physical exam findings of altered mental status and asterixis
features of DIC including hemolytic anemia (↓ haptoglobin, ↑ LDH, ↑ indirect/unconjugated bilirubin, ↑ reticulocytes), thrombocytopenia, elongated PT/PTT, and signs of acute kidney injury (increase creatinine and blood urea nitrogen (BUN))
What is the first-line ab therapy for asymptomatic bactiuria during pregnancy?
Amoxicillin/clavulanate
A congenital neural tube defect in which part of the vertebrae fail to close. The spinal cord, spinal meninges, and overlying skin remain intact. Most commonly occurs in the lumbosacral region, and is usually asymptomatic. There may be a visible dimple, collection of fat, or patch of hair on the skin above the defect.
Spina bifida occulta
What is the most likely cause of spina bifida occulta?
Folate deficiency
What is the difference between an open and closed NTD (neural tube defect)?
A closed NTD and would not show increased α-fetoprotein and acetylcholinesterase levels in the maternal serum or amniotic fluid. This defect is not associated with polyhydramnios on prenatal ultrasonography. Spina bifida occulta, lipomyelomeningocele, and lipomeningocele are examples of a closed NTD.
Open will show increased AFP and is associated with polyhydramnios, these defects influse meningocele, myelomeningocele, myelochisis, myelocele, anencephaly (cranial defect).
A lethal neural tube defect (NTD) characterized by an open cranial vault and absence of the forebrain.
Anencephaly
What is the highest risk factor for anencephaly?
Folate deficiency
What is the single most accurate method of estimating the gestational age in the first trimester (error ± 5–7 days)?
Ultrasonographic measurement of crown-rump length (CRL)
Reproductive age female with hx of multipe miscarriages and dvt and presents with prolonged aPTT is highly consistent with what condition?
Antiphospholipid syndrome
Elevated alpha feto protein and a large fundal height at 16 wga should raise your suspicion of
multiple gestation, note that polyhydramnios is not in itself associated with abnomal AFP levels.
Women with vaginal bleeding in pregnancy, you should first check to see _____________________
if they have gotten their blood type, any bleeding in pregnnacy poses a risk for rh sensitization
What antibody measurement is used to help diagnost APS?
The presence of procoagulant antiphospholipid antibodies such as anti-β2-glycoprotein 1 antibodies confirms the diagnosis of APS.
More about the physiology:
The antibodies in APS are thought to form complexes with anticoagulant proteins, thereby inactivating them (e.g., protein C, protein S, antithrombin III), and activate platelets and vascular endothelium. These effects induce a hypercoagulable state with an increased risk of arterial and venous thrombosis as well as pregnancy loss.
Use of these medications interferes with folate metabolism which often induces a deficiency. Common features of this syndrome include intrauterine growth restriction, craniofacial abnormalities (e.g., cleft palate, hypertelorism, slanted palpebral fissures, and low-set ears), a short neck, limb defects (phalanx/fingernail hypoplasia), and excessive hair on the body and face.
Hydantoins, Fetal hydantoin syndrome is a collection of defects associated with maternal exposure to phenytoin and other hydantoins (e.g., fosphenytoin).
Atrialization of the right ventricle secondary to caudal displacement of a tricuspid valve leaflet is caused by Ebstein anomaly, which is strongly associated with ______________ use during pregnancy, especially during the first trimester.
lithium
A congenital heart defect characterized by caudal displacement of a tricuspid valve leaflet that results in atrialization of the right ventricle, tricuspid regurgitation, and right atrial enlargement.
Ebstein anomaly, it is strongly associated with lithium use during pregnancy
What is the first line tx for graves in pregnancy for first trimester, 2nd, and 3rd?
1st: propylthiouracil
2nd: methimazole
3rd: methimazole
Increased minute ventilation due to ___________________ acting as a respiratory stimulant causes a compensation respiratory _______________________
progesterone, alkalosis
On PFT, what is expected to change in pregnancy?
Normal changes observed in pregnancy include increased inspiratory capacity (by 15% during the third trimester), increase in TV, and increase in inspuratory reserve volume. RR does not change but TV does thereby increasing the minute ventilation hence a respiratoy alkalosis in pregnancy. Functional residual capacity is reduced. This all contribute to SOB in pregnancy.
Common causes of acute pulmonary edema in pregnancy include…
tocolytic use, cardiac disease, fluid overload, and pre-E.
What leads to hydronephrosis in pregnancy?
Dialation (particualry R>L) occurs due to dextrorotation of the uterus and compression byt the right ovarian vein.
What happens to thyroid levels in pregnancy?
It is normal to have elevation of T4 and T3. Thyroid binding globulin is increased due to increased estrogens. Total T3 increase while T3 free do not change. In pregnancy patients without iodine deficiency, the thyroid may increase in size up to 10%.
A patient at 8 wga comes in without polyuria, dysuria, or urinary urgency. Their urinalysis shows elevated glucose. What is this indicative of?
This is NOT indicative of GDM- its too early in the pregnancy to dx and with pregnancy, the increase GFR in combo with inpaired tubular reabsorptive capacity for filtered glucose accounts for most cases of glycosuria.
What is appropriate weight gain in pregnancy for someone with a BMI of 18.5-24.9 (normal weight)?
25-35
What is appropriate weight gain in pregnancy for someone with a BMI of less than18.5 (underweight)?
28-40
What is appropriate weight gain in pregnancy for someone with a BMI of 25-29.9 (overweight)?
15-25 lbs
What is appropriate weight gain in pregnancy for someone with a BMI of over 30?
11-20 lbs
What is the most common form of inherited intellectual disability?
Fragile X
In a normal pregnancy, b-hcg levels should rise by at least ______ every 48 hrs until the pregnancy is about 42 days old.
50%
What leads to a hypercoaguable state in pregnancy?
Expression of coag factors I, II, VII, VIII, IX, and X. They are overexpressed while the anticoagulant protein S is underexpressed. Additionally, hormonal changes and compression of the uterus leading to venous stasis and pooling of blood in the lower extremities.
A patient at 16 wga is treated for asymptomatic bactiuria due to GBS. What followup care would be appropriate managment?
Maternal antibiotic therapy in labor
Regardless if they screen them at 36 weeks, the hx of GBS marks them as GBS + and should be given AB’s in labor.
What are possible causes of hyperthyroidism in pregnancy?
Graves disease or stimulation of the TSH receptor by hCG (recall that the beta subunit of hcg is similar to TSH). Less common causes are toxic multinodular goitertoxid thyroid adenoma, and thyroiditis.
What are the signs of thyrotoxicosis?
Diaphoresis, weight loss, anxiety, palpitations, tremor, and tachycardia. They may have other signs of hyperthyroidism like exopthalmos likely from underlying graves.
In normal pregnancy, what happens to TSH and T3, T4?
TSH decreases
T3 and T4 are elevated
In pregnancy, thyroxine-binding globulin decreases and circulating hcg can cause decreased TSH. Work up for hyperthyroid in pregnancy should start with free T4.
See screen shot for full explanation of thyrotoxicosis in pregnancy.
Fetal renal agensis would result in _______________
oligohydramnios
Fetal esophageal atresia would result in ________________
polyhydramnios
What are the major causes of DIC in pregnancy?
placental abruption, pph, pre-e and e, HELLP, AFLP, amniotic fluid embolism, and trauma.
How do we tx DIC in pregnancy?
fresh frozen plasma
What can lead to fetal goiter?
Inborn errors of thyroid metabolism, developmental abnormaltiies, iodine excess or deficiency, transplacental passage of maternal thyroid stimulating antibodies (ie graves), or transplacental passage of antithyroid drugs such as propylthiouracil (PTU)
Which of the following should be discontinued in pregnancy:
Lenothyroxine
labetalol
acyclovir
butalbital
lisinopril
Lisinopril
The most common cause of sepsis in pregnancy is
acute pyelonephritis
For bacterial vaginosis in pregnancy, what is the protocol?
Treat right away, no need to treat again at labor unless reinfected
Mitral valve prolapse in pregnancy is tx’d with
beta blockers
A 26 wga pt comes in concerned for intense pruritis all over including the soles of her feet. What is the most likely cause and what tx should you consider?
Most likely she has intrahepatic cholestasis of pregnancy. Ursodeoxycholic acid releives the itching.
What si the mainstay approach for dx’ing appendicitis in pregnancy?
Graded compression US, its sensitive and specific before 35 wga
What tocolytics are contraindicated in type 1 diabetics?
Terbutaline and ritodrine
In premature preterm rupture of membranes, why is tocolysis still used?
Although controversial, it may be appropriate to use tocolytics to prolong the interval to delivery in order to gain time for steroids to obtain the macimum benefit. Risks of chorioamnionitis beyond 48 hours outweighs the benefit of awaiting lung maturity.
With pts of preterm labor at 34 weeks, what do we ive them to prolong the latency period by 5-7 days?
ampicillin and erythromycin
In general, when do we use corticosteroids in labor? (What time frame)
24-34 wga
