Belly Basics: “Mapping Out” Prenatal Care

Susanna Magee, MD MPH

Objectives

• Become familiar with the general components of prenatal care

• Be able to recognize high risk conditions, not necessarily treat them

• Develop ability to use our Centricity prenatal care map as a tool to administer and improve prenatal care

• Understand the importance of appropriate documentation

First Trimester Objectives • Risk Assessment

– Intake visit with nurse, social worker and nutritionist

– History and Physical – Intake labs including CF, Tay Sachs, MaterniT21 or

Harmony where appropriate • Health Promotion

– Begin Prenatal vitamins/DHA/folate – Counseling and Education, Immunizations

• Pregnancy Dating – Ultrasound for uncertain dating – Counsel on genetic screening options

History

• Review intake notes from nurse, social worker, and nutritionist (*L)

• Review patient medical/surgical history

• Review past OB history noting type of delivery, gestational age, labor duration, weight of infant, maternal/infant complications

History • Paternal/Family History including h/o

congenital anomalies • Medication Allergies/Anesthesia reactions • Gyn Hx: Abnormal Pap Smears, cryo or

LEEP procedures • Create Problem List, review and update

each visit – where does this go? (*L)

Physical Exam • Thorough head to toe

exam – Vitals – General – obese? flat

affect? – Thyroid – Breast exam – CV - is there need for echo

(pathologic) or is this just a flow murmur?

– Abdomen- scars – Baseline reflexes – Pelvic and Pelvimetry

• Lost art

Physical

• Pelvimetry: – Inlet = Obstetrical (true)

conjugate which is distance from sacral promontory to superior aspect of pubic symphysis (10-12 cm).

– Mid = distance between ischial spines (>10cm), note sacral concavity and inclination

– Outlet = pubic arch, distance between ischial tuberosities (8cm), coccyx

Physical

• DOCUMENT COMPLETE PHYSICAL EXAM (*L)

First Trimester Labs • Baseline CBC - check for anemia • RH factor-Potential Need for Rhogam

– presence of D antigen on RBC means Rh+, absence of D antigen means Rh -

• Antibody Screen - checks for antibodies against major and minor antigens on maternal RBC membrane – anti D antibodies means isoimmunization in

Rh( -) women – Review other major/minor antigens like

Kell/Duffy etc – Pathologic vs. Non-pathologic

Labs

• Hepatitis B surface antigen (HBsAg) to check for Hep B infection. – Earliest detection – + in active, chronic and

carrier state – If positive, further

testing warranted

Labs

• Urine C & S – Ideal screening time approx 12 weeks – Higher risk for UTI – Remember to treat asymptomatic bacteriuria in

pregnancy. • Controversy: how many colonies are bacteriuria • Always get repeat UA/C&S as TOC after treatment

– Any GBS = prophylaxis in labor against GBS – 2 UTIs or 1 pyelonephritis buys prophylaxis

against repeat infection

Labs

• Rubella antibody • Syphilis screen (RPR, STS, VDRL)

– If positive, obtain confirmatory FTA-ABS qualitative.

– If FTA-ABS positive, obtain quantitative screening titer (RPR) and treat accordingly with PCN

– Follow titers of RPR q 4-6 weeks – Treat as indicated

Labs

• PAP, GC, Chlamydia, Wet mount (if indicated) done at initial OB exam – History of PTB/symptomatic d/c: wet mount – Repeat GC / Chlam third trimester for high risk women

• Those under 25 yo included as high risk according to CDC

• HIV - All pregnant women should be counseled and offered test. If patient declines, document – RI state law requires testing of newborns for moms who

decline • +/- Obtain Hgb electrophoresis

Labs

• For high risk patients, place PPD and read in 48-72 hours. If positive (review guidelines), check CXR. – no need to delay xray – If PPD+, CXR - : INH for 9 mo postpartum

(TB clinic starts about 3 months pp) – Do not attribute +PPD to childhood BCG

vaccination • Quantiferron gold

Labs

• Obtain intake 1 hour non fasting 50 g glucose screen: – history of abnormal glucose value or gestational

diabetes – consider if multiple historical risk factors

• family history • prior macrosomia • obesity • congenital anomaly • IUFD

Labs • Toxoplasmosis, Varicella, CMV,

Parvovirus, HCV, HSV titers not routinely recommended.

• Obtain UTOX in high risk patients, especially if they present late for care, frequently miss appointments or admit to drug use. – Follow up + UTOX at least q trimester

Vaccinations

• May give Hepatitis B, TdaP, and Influenza during pregnancy. – May start hepatitis series at intake. – TdaP best given 28-36 week window to confer

passive immunity to infant – Influenza vaccine indicated for all pregnant

woman regardless of gestational age during flu season (Oct - Mar)

Medications

• PNV • Folic acid (0.4 mg or 4 mg) • DHA • ASA 81 mg? • Calcium 1 g? • Progesterone (vaginal or oral?)

Pregnancy Dating (more in the second trimester)

• Naegele’s Rule: EDD = FDLMP + 7d - 3m

• LMP • Uterine size at intake • Conception • Ultrasound findings • hCG levels

Pregnancy dating LMP and u/s correlation

• 0-9 weeks +/- 4 days • 10-13 weeks +/- 7 days • 14+ weeks +/- 10 days

Ultrasounds

• Dating • NT • Fetal survey

• Level 2 • Cervical length

Counseling and Education

• Monthly visits • Encourage breastfeeding right from initial

visit – Definitively by 20 weeks

• Ensure safe environment/confirm supports – Volunteer doula program – Group visits

• Substance abuse counseling

Second trimester

Cruising along...

Second Trimester

• Definition: 12-24 weeks • At and around 23-24 weeks, viability issues

– Importance of accurate dating • Prenatal visits are typically every 4 weeks

Second Trimester

• 3 issues: – Housekeeping – Completing genetic

screening tests – Establish dating

Housekeeping

Is the BTL signed and faxed to WOOD 2? H and P done? Intake? Labs documented? Is your name listed as provider? Are previous deliveries entered? Problem list updated? Dating finalized?

Screening

• Discuss genetic testing with your patient and DOCUMENT pt’s decision.

– What are the five screening tests? – When should they be offered?

Prenatal Screening Tests

• Maternal serum markers and / or u/s findings to help identify patients at risk for fetal malformations and chromosomal abnormalities.

• Quad test includes α-fetoprotein (MSAFP), inhibin A, unconjugated estradiol (uE3) and human chorionic gonadotropin (hCG)

• AFP (most studied) is a protein made by the yolk sac, fetal GI tract and fetal liver. Peaks in amniotic fluid by 12-14 weeks, detectable in maternal serum by 15-18 weeks

• Defect in fetal skin or fetal bleeding increases AFP in amniotic fluid and therefore maternal serum

Prenatal Screening Tests

AFP

High levels, > 2.0 MoM (Multiples of the Mean) may indicate the following:

neural tube defects, abdominal wall defects, impending fetal death, multiple gestation, ectopic pregnancy, maternal hepatitis, herpes infection, Rh disease, and fetal growth restriction

Low levels, < 0.25 MoM • Suspect chromosomal abnormality

– primarily Down’s Syndrome (5%), molar pregnancy or fetal demise

History of Spontaneous Preterm Birth 17 P

• Efficacy of Progesterone • 36.3 treatment vs. 54.9 % placebo delivered at < 37

weeks • 20.6 vs 30.7% at < 35 weeks • 11.4 vs 19% at < 32 weeks

– lower risk NEC, IVH and need for O2

History of Preterm Birth FFN vs. cervical length

• FFN – 22 and 34 and 6 – intact membranes – < 3 cm dilation – no intercourse or cervical manipulation within 24 hours – fFn first--before other samples or manual cervical check

– high negative predictive value

• 1/1000 change delivery in 7 days if neg • + predictive value poor, but as many as 14% will deliver within 2

weeks

Incidental short cervix

• Ex: Found on fetal survey 18 weeks – Cervix <2.5 cm in length

• Vaginal Progesterone, Cerclage, Pessary – Data to support all three – We tend to choose progesterone 18-36 weeks

gestation – HROB referral

Am J Obstet Gynecol. Author manuscript; available in PMC Jan 1, 2013.

Third Trimester The homestretch

Third Trimester

• Definition: 24 weeks (viability) and beyond • Number of Prenatal Visits

– Monthly until 28-32 weeks, then biweekly visits at 32-34 weeks, and weekly after 36 weeks

• Continued Risk Assessment – Domestic violence, symptoms of depression,

excessive weight gain, etc.

Third Trimester Counseling/Visits

• 24-34 weeks – Repeat Risk Assessment…Update Problem List

• Consider influenza/hepatitis B vaccine

– Suggest prenatal classes / teaching ultrasound / handouts

– Discuss breastfeeding, +/- circumcision, contraception plans, home preparation, identify labor support

– Confirm fetal presentation – Review dating

• VBAC-counseling high risk appointment at 32-34 weeks • RCS-34 weeks • BTL consents at 28 weeks FOR ALL PATIENTS

Third Trimester Labs

• Ensure previous trimester labs are complete and documented!

• 26-28 weeks: 1 hour glucose screen (GDS2) • Order 3 hour screen (after the patient has followed a

high carb diet for 3 days) if 1 hour is > 130 (Carpenter & Coustan)

– Repeat H & H – Repeat STS in high risk women – Repeat HIV GC Chlam in high risk women

• Defined by ACOG as all under age 25…..

Third Trimester Labs

• If pt. Rh -, time to order Antibody Titers and give Rhogam (with 26-28 week labs) – Order Rho Studies (on red lab sheet, check

Type and Screen, and Rho box) – Lab will test maternal sample for anti-D Ab

• standard is 300 mcg – Mom has 10 days to come in for shot

• If they miss, need to repeat the Rho studies to be sure the dose of Rhogam is correct

Third Trimester Labs

– Standard dose Rhogam is 300 µg, which covers a 15 ml or less mix of maternal fetal blood.

– Rh Immunoglobulin (Rhogam) is good for 12 weeks

Rh Special Situations

• If patient has vaginal bleeding in pregnancy and is known to be Rh-, she should have Rho studies and receive Rhogam

• If she presents days after the bleeding occurred, then order Rho studies to see if she has already produced anti-D Antibody

• If she has not, then give Rhogam – If she already had made anti-D Ab, then its too late to

give the Rhogam

Third Trimester Labs • 35-40 weeks

– GBS vaginal rectal screen is recommended by ACOG and AAFP for all pregnant patients at 35-37 weeks gestation

– Swab is considered interpretable for up to 5 weeks

• If positive, PCN in labor • If low risk PCN allergy: Ancef • If high risk PCN allergy: sensitivities must be done to Clinda Erythromycin,

and Vancomycin • If patient had GBS in urine during pregnancy, then requires Prophylactic Rx in

labor and no need vag/rectal swab • Document your results and treatment plan

Third Trimester Labs

• You’re now at 40 weeks….what tests do you recommend?

Third Trimester Labs

• Answer: NONE! – No postdates testing is needed until pregnant

woman reaches 41 weeks unless there is some other indication

• Decreased fetal movement • Leaking fluid...

• What test should be done at 41 weeks?

Third Trimester Labs

• Answer: Best Evidence weighing cost benefit ratio is for NST/AFI, otherwise known as modified BPP – Provides an immediate evaluation of fetal well-

being (NST) and uteroplacental function (AFI) – What is an abnormal test?

• If NST abnormal (non-reactive, presence of deep or prolonged variable decelerations, presence of late decelerations)

• If AFI < 5 (5-8 considered low normal and will require repeating in 2 days)

Third Trimester Labs

• What is the evidence? – Has not been studied in a randomized

prospective fashion – Miller et al 1996--largest and most respected

study • Retrospective series of 15,482 high and low risk

pregnancies in which 56,617 MBPP’s were performed as the initial fetal surveillance test

Miller et al, continued

• Positive Predictive Value (diagnostic accuracy of an abnormal test to predict a compromised fetus) – When applied to low risk conditions, the

positive predictive value is not very good • Negative Predictive Value (diagnostic accuracy of

a normal test result to predict a healthy fetus) – Comparable to the use of the BPP or CST, and

is much higher than the NST alone)

Miller et al, continued

• Evidence to date suggests that using NST AFI together at 41 weeks, 41.5 weeks and 42 weeks results in a 50% decrease in the rate of fetal demise after a normal test result – 0.8 fetal deaths per 1000 versus 1.9 fetal deaths

in 1000) • Note number of tragic outcomes very small • There is no evidence to suggest that testing be done

before 41 weeks

Postdates….uggh!

• What do we do with this information? – Once patient approaching 41.0 weeks, need to

discuss induction plan – Plan should be documented and begin at 41+

weeks +/- and reviewed with the attending on call

• “Stripping membranes” – Some evidence that stripping at 37 weeks (term) prevents

the need for postdates management

How to determine ripening vs. induction

• Bishop’s scoring

– Help assess the need for cervical ripening vs. straight induction with oxytocin

– See form next page

Third Trimester Review

• Utilize the Prenatal Care Map • Document Labs and Relevant Information

on the Problem List • Your MCH Faculty are always available

– If they don’t know the answer, they’ll find it out! Then everyone learns.

– Utilize OB Floor Preceptors in a Pinch

GET HELP • Please precept your EDC • Please precept your

bimanuals/pelvimetry • Please review your EDC

and your labs each visit • Print an OB Summary

every trimester to be sure it is properly filled out

• If there are items not populating the care map contact Cathy Masterson.

ENJOY THIS EXPERIENCE

• Your hands may be the first ones to ever touch another human being, even before their parents…

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