PrenatalCare

Prenatal Care: 

Prenatal Care Christian T. Hanley, Jr., MD Maj, USAF, MC, FS FP/FS Andrews AFB, MD Slides Courtesy: Pamela M. Williams MD

Learning Objectives: 

Learning Objectives Understand and apply the concepts of preconception healthcare List the components of and understand the rational for the initial prenatal assessment Describe the purpose for and components of routine prenatal care visits

Slide3: 

Preconception Health Care

Case #1: A 23 y.o. G0 presents to discuss pregnancy planning. She has no significant medical history. Which of the following should you discuss during the pre-pregnancy discussion?: 

Case #1: A 23 y.o. G0 presents to discuss pregnancy planning. She has no significant medical history. Which of the following should you discuss during the pre-pregnancy discussion? Rubella immunization status. Intake of folic acid. Avoidance of alcohol. Work & home exposures, such as tobacco and chemicals. All of the above

Goals of Preconception Care: 

Goals of Preconception Care To identify modifiable and non-modifiable risk factors for poor obstetrical outcomes To intervene when modifiable risk factors are identified To provide preventative healthcare To perform individualized counseling including information on the benefits of planned pregnancy

Key Elements: 

Key Elements Genetic risk assessment Prevention of congenital infections Screening for environmental toxins Assessment of chronic diseases

Genetic Risk Assessment: 

Genetic Risk Assessment Prevent neural tube defects (NTD) Folic acid reduces incidence of NTDs Recommend minimum dose: 400 mcg/day Higher dosing necessary if diabetic, epileptic or delivered prior infant with NTD Counsel about risks of advanced maternal age Assess need for carrier screening

Prevention of Congenital Infections: 

Prevention of Congenital Infections HIV & Syphilis: preconception identification and treatment reduces transmission Toxoplasmosis/ CMV/ParvoB19 screening not advised…but education is! Immunizations: Hepatitis B Immunize those at risk Safe in pregnancy Rubella and varicella Assess for immunity Vaccinate nonimmune LIVE Virus: delay conception x 3 months

Screen for Toxins & Exposures: 

Screen for Toxins & Exposures Does she smoke? How can you help her stop? Does she drink alcohol? How much? Does she use drugs? Does she have any concerning occupational, environment or household exposures?

Chronic Disease Assessment: 

Chronic Disease Assessment Identify any preexisting medical conditions which may impact patient or a fetus Maximize pre-pregnancy health prior to conception Minimize use of potentially teratogenic medications

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Initial Prenatal Assessment

Initial Prenatal Assessment: 

Initial Prenatal Assessment Purpose: To perform a baseline assessment of risk factors for pregnancy complications To establish care plan with referral as needed To treat any identified disease conditions Provide patient education

Prenatal Screening Exam: 

Prenatal Screening Exam Physical exam: why do we do it? Complete exam with pelvimetry & fetal heart tones recommended Only BP, wt, and ht assessments have been associated with improved outcomes Initial Screening Labs: ABO & antibody screen, Hgb/Hct, Rubella, PAP smear, RPR, GC/Chlamydia, Urine culture, Hep B, HIV

Educating our patients: 

Educating our patients Tobacco/alcohol/drugs Breastfeeding Sex Hot tubs & saunas Plan of care Nutrition & weight gain Exercise Early warning signs Common discomforts Domestic violence

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Routine Prenatal Care

Case #2: Your 23 y.o. G0 returns for routine prenatal care at 16 wks gestation. She feels well and is without complaints. Which of the following tests would you typically offer at this visit?: 

Case #2: Your 23 y.o. G0 returns for routine prenatal care at 16 wks gestation. She feels well and is without complaints. Which of the following tests would you typically offer at this visit? MSAFP/triple screen Fetal ultrasound Rh D test Amniocentesis Non-stress test

Routine Prenatal Care: 

Routine Prenatal Care Purpose: Continues risk assessment and preventative counseling Timing & Frequency: A subject of debate Key components: History: what are you looking for? Exam: BP, weight, fundal height, doptones Prevention: Influenza vaccine Patient Education

When do I get my ultrasound?: 

When do I get my ultrasound? Routine ultrasound…. Improves patient satisfaction Detects twin gestations earlier Reduces rate of induction for postdates Provides earlier detection of clinically unsuspected fetal malformations Further significant benefits are unclear

Screening in 1st and 2nd trimester: 

Screening in 1st and 2nd trimester Cystic fibrosis screening Multiple marker testing Preventing isoimmunization Gestational diabetes screening

Cystic Fibrosis 101: 

Cystic Fibrosis 101 Most common autosomal recessive disease Carrier frequency 1/29 in Caucasians Incidence 1/3300 live births Mutations in the CFTR gene Defective chloride channel function Clinical triad: 1) pancreatic insufficiency, 2) chronic suppurative pulmonary disease, and 3) salt loss in sweat

Cystic Fibrosis: why do we screen?: 

Cystic Fibrosis: why do we screen? To identify carriers in at risk populations to help with reproductive decision making To allow time for education if a fetus with CF is identified To enable individuals to terminate the pregnancy of a fetus with CF To institute treatments earlier to prevent complications of the disease

Who do you screen?: 

Who do you screen? Screening should be “offered” to Individuals with a family history of CF Reproductive partners of individuals with CF Couples in whom one or both are Caucasian and are planning pregnancy or seeking prenatal care Screening should be “made available” “to couples in other racial and ethnic groups who are lower risk and in whom the test may be less sensitive” ACOG, ACMG. 2001.

Screening Method: 

Screening Method DNA sample obtained for multi-mutation analysis Pan-ethnic panel including all mutations with an allele frequency of at least 0.1% Current panel: 25 mutations Sequential vs. concurrent screening

Interpreting the Results: 

Interpreting the Results Risk estimation Directly related to ancestry Sensitivity is a function of number of mutations searched for in the panel Negative screen does not mean no risk Result =Residual risk

Dealing with Positive Results: 

Dealing with Positive Results For the individual identified as a carrier: Recommend testing of father of baby ASAP Consider offering genetic counseling For the couple who are both positive: Chance of having an affected baby 1 in 4 Prompt referral for genetic counseling with discussion of prenatal testing

Multiple Marker Testing: 

Multiple Marker Testing Screening test for Down Syndrome (trisomy 21) Edward’s Syndrome (trisomy 18) Neural tube defects Measures circulating levels of Alpha-fetoprotein (MSAFP) Unconjugated estriol Human chorionic gonadotorpin (hCG) Quad test: Dimeric inhibin-A (INH-A)

Multiple Marker Testing: 

Multiple Marker Testing When do we screen? USPTF recommends offering test between 15-18 weeks What are the results? Values reported as multiples of the median (MOM) Abnormal screen: MSAFP > 2.5 MOM Mid-trimester risk > 1:270 for Down syndrome

Down Syndrome (Trisomy 21): 

Down Syndrome (Trisomy 21) 1/800 Live births Risk increases with advancing maternal age Lab findings Elevated hCG + INH-A Lower than average levels of MSAFP and unconjugated estriol

Edward’s Syndrome (Trisomy 18): 

Edward’s Syndrome (Trisomy 18) 1/5000 live births High rate of fetal and neonatal death Lab findings: Lower than average levels of all three markers

Open Neural Tube Defect: 

Open Neural Tube Defect 7-15/10,000 live births Adequate folic acid reduces incidence Lab findings: Elevated MSAFP

Approach to the Abnormal Result: 

Approach to the Abnormal Result Confirm dates and number of fetuses Consider repeat testing if drawn prior to 15 wks EGA Genetics consult with level II ultrasound + amniocentesis Fetal surveillance if evaluation is negative

Preventing Isoimmunization: 

Preventing Isoimmunization Why? Rh negative women are at risk of developing antibodies to the Rh antigen on fetal cells Once sensitized, subsequent Rh positive fetus is at risk for severe hemolysis Anti-D immunoglobulin markedly reduces risk of isoimmunization

Preventing Isoimmunization: 

Preventing Isoimmunization Who & when? Screen all women at initial visit with ABO and antibody screen Treat Rh negative women with Rho D immunoglobulin (300 mcg IM of RhoGAM) Routinely at 28 wks to all Rh neg women Within 72 hrs postpartum if infant is Rh + After episodes of vaginal bleeding, pregnancy loss, invasive procedures, or trauma

Screening for Gestational Diabetes: 

Screening for Gestational Diabetes Why screen: Identify women at risk for AODM in future Treat in an attempt to reduce maternal, fetal and neonatal morbidity Performed at 24-28 wks EGA Who? selective vs. universal screening debated

Risk Factors for Selective Screening: 

Risk Factors for Selective Screening Age > 25 yrs BMI > 25 Prior history of GDM or abnormal glucose test Family history of DM in first degree relative Obstetric history: Prior macrosomic infant or unexplained fetal death Race: Asian, Hispanic, Native American, Black

Initial Screen: 

Initial Screen 50 gram glucose load consumed by nonfasting patient Serum glucose drawn 1 hour later Threshold > 140 mg/dl Correctly identifies 90% cases Lower thresholds may be used

Confirmatory Testing: 

Confirmatory Testing 3 hr 100-gm glucose challenge Fasting and 1, 2 & 3 hours post-consumption glucose levels drawn Positive test: 2 or more values exceed accepted thresholds Acceptable thresholds: Carpenter/Coustan: 95/180/155/140 Natl Diabetes Data Grp: 105/190/165/145

Slide38: 

Third Trimester Care

Prenatal care in the 3rd Trimester: 

Prenatal care in the 3rd Trimester Purpose: Ongoing risk assessment & preventative counseling Components: Add in assessments of fetal lie cervical exams postdates testing Patient education: Prepare for delivery! Screening for Group B strep (GBS)

Case #3 You are taking obstetrics call when a 28 yo G2P1 at 38 wks presents in active labor. Her membranes are intact. She tells you that her vaginal culture at 36 wks was positive for Group B strep. She denies any drug allergies. She is afebrile. Do you?: 

Case #3 You are taking obstetrics call when a 28 yo G2P1 at 38 wks presents in active labor. Her membranes are intact. She tells you that her vaginal culture at 36 wks was positive for Group B strep. She denies any drug allergies. She is afebrile. Do you? Begin penicillin G 5 million units IV, then 2.5 million units q4 hrs until delivery Do nothing because you only need to give her antibiotics if she develops a fever. Order penicillin G 5 million units IV to be administered when she begins pushing. Begin Vancomycin 1g IV q12 hrs until delivery

Screening for GBS: 

Screening for GBS Why do we do it? Early onset GBS disease is the leading infectious cause of illness and death in US newborns Administering intrapartum antibiotics (IAP) to colonized women prevents invasive disease in infants

Slide42: 

The Recommendations MMWR, Vol 51 (RR-11)

Who do we screen?: 

Who do we screen? Universal prenatal screening at 35-37 wks gestation Exceptions: previous infant with invasive GBS or GBS bacteriuria during current pregnancy Risk based strategy reserved for women with unknown GBS culture status at the time of labor www.cdc.gov/groupBstrep

How do we screen?: 

How do we screen? Site: lower vagina and rectum single swab or two swabs through anal sphincter Timing: 35 to 37 weeks Collection: speculum NOT required self collection an option Processing: selective broth medium Sensitivity testing: if PCN allergic

Indications for IAP: 

Indications for IAP Previous infant with invasive GBS disease Positive GBS culture during current pregnancy Unknown GBS status and any of the following: Delivery at <37 weeks of gestation Amniotic membrane rupture ³18 hours Intrapartum temperature ³100.4°F (³ 38.0 °C) www.cdc.gov/groupBstrep

Intrapartum Prophylaxis Not Indicated: 

Intrapartum Prophylaxis Not Indicated Previous pregnancy with a positive GBS culture (culture negative in current one) Planned cesarean delivery performed in absence of labor or rupture of membrane (regardless of maternal GBS status) Negative vaginal and rectal GBS screening in late gestation during current pregnancy, regardless of intrapartum risk factors www.cdc.gov/groupBstrep

Agents for IAP: 

Agents for IAP www.cdc.gov/groupBstrep

Agents for IAP if PCN allergic: 

Agents for IAP if PCN allergic www.cdc.gov/groupBstrep

Prenatal care….: 

Prenatal care…. Begins with preconception counseling Involves continuous risk assessment Represents a key time for preventative counseling and interventions Ultimate goal: Healthy outcome for mom and baby

Questions?: 

Questions?