FUNDAMENTALS OF OBSTETRICS Christine Pecci, MD Associate Clinical Professor UCSF Department of Family and Community Medicine March 2018
FUNDAMENTALS OF OBSTETRICS
Christine Pecci, MDAssociate Clinical ProfessorUCSF Department of Family and Community MedicineMarch 2018
OBJECTIVES
Review criteria for ultrasound vs LMP dating Review management of women at risk for
preterm delivery Describe guidelines for diagnosis, treatment and
management of: nausea and vomiting in pregnancy Preeclampsia gestational diabetes thyroid disease in pregnancy
List infections in pregnancy and how to manage or prevent these from occurring
Review Tdap recommendations in pregnancy
Tanya is a 23 yo G1P0 who presents for early pregnancy care. EGA 10 1/7 wks by a sure LMP
She had a visit to ED for nausea and vomiting Given 1 liter NS Electrolytes were normal TSH 0.1
NAUSEA AND VOMITING IN PREGNANCY
Nausea in 50-80% Vomiting/retching 50% Hyperemesis gravidarum 0.3-3%
Persistent vomiting Weight loss Ketonuria Usually electrolyte, thyroid, liver abnormalities
Lower rate of miscarriage
ACOG Practice Bulletin Jan 2018
TREATMENT OF N/V IN PREGNANCY
Multivitamin x 1 month before conception Ginger may decrease nausea Acupuncture/acupressure- no difference in RCTs
First line treatment pyridoxine +/- doxylamine Metoclopromide, ondansetron second line
Limited safety data, but overall risk low Oral corticosteroids used as last resort– avoid 1st
trimester
ACOG Practice Bulletin April 2015
NORMAL THYROID FUNCTION ANDPREGNANCY
Hcg stimulates TSH receptor, increasing thyroid production and decreasing TSH
Total thyroid hormone levels increase due to elevated thyroid-binding globulin (TBG)
Free T4 unchanged (direct assays ok but many labs use automated assays which can be inaccurate)
TSH is a reliable indicator of maternal thyroid status (American Thyroid Association) First trimester 0.1-2.5 mIU/L Second trimester 0.2-3.0 mIU/L Third trimester 0.3-3.0 mIU/L
HYPERTHYROIDISM IN PREGNANCY
Avoid meds in 1st trimester If medication needed, use PTU
risk of liver failure Risk face and neck cysts
Consider changing to methimazole after 16 wks(aplasia cutis) other congenital malformations
Smallest possible dose as medications Moniter TSH/T4 every 4 wks if on medication
HYPOTHYROIDISM AND PREGNANCY
50-85% need increase in thyroid replacement Preconception treat to <2.5 Should increase dose by 25-30% ASAP post
conception (can give two extra pills/wk)
Postpartum following delivery go back to pre-pregnancy dose and recheck in 6 wks
If Rx started in pregnancy with nl TSH reasonable to stop and recheck in 6 wks
SHOULD WE BE SCREENING FORHYPOTHYROIDISM? Case control trials showed hypothyroidism
associated with low IQ in the fetus RCTs do NOT confirm that treatment of
subclinical hypothyroidism improves neurocognitive outcomes Both initiated Rx after first trimester
Universal screening for thyroid disease in pregnancy is not indicated* Effectiveness of Rx not yet proven
*ACOG, Endocrine Society, American Association of Clinical Endocrinologists
INITIATING SUPPLEMENTATION
Treat if TSH >10 TSH>2.5 check TPO Ab status ?treat if TPO Ab+ and TSH >2.5 Don’t treat if TPO neg and TSH > upper nl <10
If treating Target lower half of preg specific range or <2.5
American Thyroid Association 2017
LMP VS. US DATING
Tanya also had an US done in the ED Crown-rump length = 9 2/7 weeks LMP 10 1/7 wks
6 days different than EDD based on LMP
Should you change her dating based on 1st
trimester US?
DATING
Gestational Age Discrepancy for re-dating w US date
< 9 weeks > 5 days (CRL)9 weeks to < 14 weeks > 7 days (CRL)14 weeks to < 16 weeks > 7 days (BPD, HC, AC, FL)16 weeks to < 22 weeks > 10 days22 weeks to < 28 weeks > 14 days28 weeks and beyond > 21 days
ACOG Committee Opinion Oct 2014
Single uniform standard based on expert opinion (ACOG, AIUM, SMFM)EDD=280 days after first day LMPHalf of women accurately remember LMP40% adjustment in 1st trimester; 10% adjustment 2nd trimesterUse earliest US
WILL MY BABY BE NORMAL? She has been reading about a new test for
making sure the baby is normal. She wants to know if you can order this test. Will having a normal test guarantee that this baby will be okay?
Options for screening
First Trimester Second Trimesterhcg + PAPP-A hcg + AFP + estradiol + inhibin11-14 wks 15-22 wksCan be combined w NT Anatomy scanAFP in 2nd trimester for NTD Includes AFP
• 1st trimester screening gives the patient early results• 2nd trimester screening good for late entry to care• DON’T do both independently• CAN do combined (7 serum markers + NT)
CELL-FREE DNA Circulating DNA fragments placental in origin
from apoptotic trophoblasts Can be done anytime after 9-10 wks gestation Available in 7-10 days Best for trisomy 21 and 18 but also screens for
trisomy 13 and sex chromosome aneuploidies Gender Can be used as primary or secondary screening
AJOG June 2016 SMFM Consult Series
I’M SO NERVOUS… Tanya is worried specifically about preeclampsia
because her sister had it and needed to be induced a few weeks before her due date.
“Is there anything that you can give me so that I don’t get this disease too?”
PREECLAMPSIA: YOU WILL SEE IT! Incidence 2-8% Has increased by 25% in last two decades Risk factor for future CV and metabolic disease
Task Force for Hypertension in Pregnancy, 2013
INITIATE ASA 12-28 WKS FOR HIGH RISK
History of pre-eclampsia, esp if adverse outcome Multi-fetal gestation Chronic hypertension Diabetes type 1 or 2 Renal disease Autoimmune disease (SLE, APS)
Practice Advisory on Low-Dose Aspirin and Prevention of Preeclampsia: Updated Recommendations July 11 , 2016
CATEGORIES
Preeclampsia-eclampsia With or without severe features
Chronic hypertension Gestational hypertension- hypertension without
proteinuria after 20 week Chronic hypertension with superimposed
preeclampsia
Task Force for Hypertension in Pregnancy, 2013
PROTEINURIA
>300 mg in 24 hrs Spot urine:creatinine ratio > 0.3 Dipstick 1+
Proteinuria is classically part of the syndrome But NOT required to make diagnosis of
preeclampsia
DIAGNOSIS
Elevated BP >140/90 on two occasions 4 hours apart
Proteinuria or “severe features” >160/110 Plts <100K LFTs twice normal Persistent RUQ pain or epigastric pain Creatinine >1.1 or double Pulmonary edema New onset cerebral or visual disturbance
WHEN TO DELIVER?Diagnosis EGA MonitoringChronic htn 38 0/7Gestational htn 37 0/7 Weekly urine dip+BP+NSTPreE (not severe) 37 0/7 Biwkly dip+BP, wkly NST, labs q wkSevere PreE 34 0/7 In hospital
If severe uncontrolled htn, eclampsia, pulmonary edema, abruption, DIC, NRFHR, IUFD deliver after initial stabilization
INTRAPARTUM INTERVENTIONS
Mg with severe preeclampsia only Anti hypertensive meds only for > 160/110 Administer steroids prior to delivery if indicated
POSTPARTUM FOLLOW-UP
Check BP 72 hours post delivery and 7-10 days postpartum
Treat for >150/100 on two occasions 4-6 hrs apart Preconception- glycemic control, weight loss
ALL patients should receive education on warning signs
ROUTINE US 18-22 WKS
Confirms dating if not already done Anatomy scan ? Cervical length
Universal screening not indicated
SCREEN FOR GDM AT 24-28 WKS
Overall incidence of DM in pregnancy 6%
90% of these are GDM Early screening- if
prior GDM, known impaired fasting glucose, BMI >30
GESTATIONAL DIABETES
HAPO trials show continuous relationship-neonatal hypoglycemia, macrosomia
Increased hyperbilirubinemia, operative delivery, shoulder dystocia
2010 International Association of Diabetes and Pregnancy Study Group (endorsed by ADA) (92, 180, 153) No data regarding therapeutic intervention
ACOG Practice Bulletin Feb 2018
DIAGNOSIS OF GDM 2010 International Association of Diabetes and
Pregnancy Study Group (endorsed by ADA) (92, 180, 153)
2013 NICHD recommends 2 step test (50 gm then 100 gm)
Consider prevalence of diabetes Consider resources One hour glucola: range 135-140fasting 1 hr 2hr 3hr
NDDG* 105 190 165 155CC** 95 185 165 140
*National Diabetes Data Group**Carpenter Coustan ACOG Practice Bulletin Feb 2018
MANAGEMENT AND TREATMENT
Diet + exercise + QID fingersticks Goal <140 on 1 hr and < 120 2 hr If fasting consistently >95, consider medication First line = Insulin (does not cross the placenta) Glyburide and metformin
Not approved but being used Glyburide crosses placenta but no measurable levels
in cord blood Metformin cross placenta and fetal levels similar to
maternal levels
ACOG Practice Bulletin Feb 2018
WHEN TO DELIVER? Induce at 39 weeks if pre-gestational or
gestational DM on meds For well controlled GDM without meds, unclear
whether induction is indicated
MODE OF DELIVERY WITH DIABETES
Prevention of a single permanent brachial plexus palsy Cesarean delivery for 4500 gm NNT 588 Cesarean delivery for 4000 gm NNT 962
POSTPARTUM FOLLOW-UP
15-50% with GDM develop DM 20+ years later Varies by ethnicity (60% Latina within 5 years)
Fasting or 2 hr GTT 4-12 wk postpartum IGT picked up by 2 hr
Repeat testing q 3 years if normal
MAY I TRAVEL? Tanya wants to travel to Cancun- A friend of hers
lives in Mexico and is getting married. Tanya is 18 wks. What do you say? A. You should absolutely go! You are past the 1st
trimester so the fetus is fully formed and not at risk of being affected by Zika, a virus carried by mosquitos.
B. No way, mosquito repellents are toxic in pregnancy so you can’t protect yourself from bites.
C. Is your partner going too? You can go as long as you are not travelling alone.
D. How good of a friend is this?
ZIKA VIRUSTransmitted by Aedes species of mosquitos Incubation period 3-12 daysSymptoms 2 or more of following
-fever, rash, arthralgia or conjunctivitisCan be transmitted in all trimestersSexual transmission has been documented via semenPrior infection confers immunity
ZIKA AND FETAL CONCERNS
Microcephaly (<3%) Congenital Zika Syndrome
Severe microcephaly where skull partially collapsed Specific pattern of brain damage and decreased brain
tissue Damage to back of eye Congenital contractures (club foot, arthrogryposis) Hypertonia
BACK FROM CANCUN! Tanya reports that the wedding was one of the
most memorable events in her life and she is grateful that you supported her travel. She used DEET, wore clothes penetrated with permethrin and slept under a mosquito net. What do you need to ask her now? A. How are you feeling? B. Are you using condoms with your partner? C. Are you planning on going to visit your newly
married friend again during your pregnancy?
HSV Genital herpes affects 20% women in US? Incidence of new infection in preg 2% Women with recurrent HSV-75% can expect
episode during preg, 14% at delivery 80% of infected infants born to women with no
reported history 20% neonatal survivors have long-term
neurosequealae
HSV-GIVE PROPHYLAXIS AT TERM
Primary infection transmission - 30-60% at delivery Recurrent infection transmission 3% at delivery; no
lesions 2/10,000 Acyclovir, famcyclovir, valcyclovir all class B, most
data on acyclovir Routine screening not recommended Genital Sx or lesions- c/s decreases transmission from
7.2% to 1.2% even after ROM
Acyclovir 400 mg TID @ 36 weeks til delivery
HIV Opt out screening for ALL women Low threshold for repeating in third trimester Offer testing on L&D for high risk women without an
appropriately timed HIV test Early viral suppression is of upmost importance Elective cesarean if VL >1000 near delivery Intrapartum AZT unless consistent VL <1000 Neonatal AZT prophylaxis required for 4-6 weeks
add if NVP high risk Consider offering presumptive treatment (AZT+NVP+3TC)
No breastfeeding (developed countries) Clinician Consultation Center Perinatal hotline 24/7
http://nccc.ucsf.edu/
GBS Screen all women at 35-37 wks, unless
Previous child with early onset GBS disease GBS bacteruria in index pregnancy
Treat with intrapartum IV penicillin first line Ask for sensitivities if has pcn anaphylaxis to see if
can give Clinda/erythro Cefazolin if no anaphylaxis reaction to penicillin Vanco reserved for those with anaphylaxis or those
without sensitivities Adequate treatment >4 hours pcn or cefazolin
RUBELLA
Do not give during pregnancy and avoid pregnancy x 28 days
Not an indication for termination If lab evidence of immunity, no need to repeat If neg or equivocal titer after 1-2 doses, give third dose
and stop checking titers Ok for children of pregnant women to get May give with Rhogam, check titer in 3 months
MMWR June 2013
VARICELLA
Lab evidence of immunity or disease
Birth in US before 1980 is not sufficient for pregnant women
Diagnosis or verification of history of varicella or zoster by health care provider Should have link to a typical
case or lab confirmation if testing done during acute infection
Tanya declined the Tdap and flu shot pregnancy because she was afraid of it hurting the baby.
Postpartum she is willing to accept these two immunizations if you still recommend them. She got the flu shot last season and got a Tdap after her last pregnancy in 2011.
Which immunizations would you give her?
TDAP IN EACH PREGNANCY
Tdap is indicated in EVERY pregnancy 27-36 wks EGA for transmission of antibodies to fetus
Once baby is out, indication for Tdap is based on maternal indications; she is up to date
Flu shot is indicated
SUMMARY
Establish accurate dating Provide primary care
Immunizations, healthy lifestyles Watch for pregnancy related diseases
Translates to risk of these diseases later in life We have interventions to prevent perinatal
transmission of disease Zika- Travel advisory HSV- Acyclovir HIV- HARRT GBS- Penicillin