Antibody positve screen in an Rh- 29 y/o P1

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Antibody positve screen in an Rh- 29 y/o P1

• Scott Ikeda
• 9/23/08
• Obstetrics Rotation

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Admission Data

• 29 y/o G6 P1041 _at_ 380 weeks by LMP (12/24/07) c/w
  27 wk sono. EDD 9/29/08. Pt c/o LOF at 11pm,
  clear, with ctrx q10 min, now q4 min. FM, -VB.

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Admission Data Contd

• PN Issues/Care
• No prenatal visit records in EPF or ASObgyn,
  however labs and sonograms available. Pt did not
  bring records with her.
• Rh negative s/p Rhogam 25 weeks
• PN Labs
• O- Ab-, GCT 132 --gt GTT 75/153/124/114 no record
  of pap, GC/Chlam all others wnl
• Sono
• 4 sonos btwn 272 weeks and 372 weeks, all c/w
  LMP, AFV wnl, no anatomic anomalies seen.
  However, fetus was noted to be gt97 for weight,
  last EFW at 372 weeks 3879g.

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Admission Data Contd

• POBHx
• 2003 7.5lb F, NSVD, term, no complications
• 2005 SAB
• 2006 TOP with DC, SAB
• 2007 TOP with DC
• PGynHx
• Menarche _at_ 14, irreg. avg 28d/1-2d no h/o f/c/p
  abnl pap in 2004, HPV ? LEEP 2005 no h/o STI
  except HPV.

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Admission Data Contd

• PMedHx
• No asthma, HTN , DM
• PSurgHx
• None, except DC noted previously
• Allergies
• NKDA
• Meds
• None
• SocHx
• No tob/etoh/drugs, in college for Med. Asst.,
  works in sales, lives w/ mother and sister, FOB
  involved, unplanned preg
• Fam Hx
• Non-contributory

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Phys Exam

• BP 130/71, P73, R20, T98.4
• FHR 130s baseline, mod var, -accels, -decels
• Toco q2-3 min
• SVE 5/90/-1
• EFW 3900, vertex by sono
• CV, Pulm, Abd exams wnl, trace LE edema b/l

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Assessment Plan

• 29 y/o P1 at 380 weeks, here for SROM at 11pm.
• Admit to LD, collect routine labs
• FEN/GI NPO except ice, IVF at 125cc/hr D5LR
• Fetal status overall reassuring, EFW 3900,
  vertex. Continue EFM.
• Labor Active labor, adequate pelvis. Expectant
  mgmt, anticipate NSVD.
• GBS Negative. No tx indicated.
• O-, Ab- may need Rhogam post partum pending
  fetal assessment.
• Pain requesting epidural, anesthesia aware

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LD Course

• 5am - 6-7/90/-1, due to lack of progress, IUPC
  placed to measure adequacy of ctrx
• 615am - O-, Ab, ctrx indadequate, no change in
  SVE, reassessed as latent/early active labor,
  pitocin started, antibody ID sent
• 845a - rim/0
• 930a - FD/0, began pushing
• 1041a- NSVD, male, 4285g midline episiotomy,
  McRoberts suprapubic pressure.
• Antibody ID Anti-D due to Rhogam. Neonate B-,
  Direct Coombs -

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Rh Alloimmunization

• Nomenclature ABO blood type plus Rh(D), Rh(D)-
• Rh, Rh- commonly used but technically incorrect
  due to other types of Rh Ab (C, c, E, e) and D
  antigen variants.
• Rh(D)- epi
• Caucasians 15, African Americans 8,
  Indo-Eurasians 2, Native Am Eskimo 1-2,
  Basques 30-35, Finnish 10-12.
• 60 homozygous, remainder heterozygous

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Pathogenesis

• Rh(D)- maternal exposure to Rh(D) RBCs
• Main cause Transplacental fetomaternal
  hemorrhage
• Iatrogenic causes re-using needles, mismatched
  transfusions, stem cell transplants
• Assoc w/ SAB, TOP, ectopic preg, invasive
  in-utero procedures, fetal death, abd trauma,
  maternal hemorrhage, AGA, delivery
• Small amounts (lt1ml) fetal RBCs cross placenta in
  nearly all pregnancies.

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Fetal Effects

• Hemolytic disease of the newborn
• Maternal anti-Rh Ab crosses the placenta and
  binds to fetal RBCs
• RBCs targeted for destruction in spleen
• Anemia ? pallor, high output cardiac failure ?
  protein synthesis as liver shifts to RBC
  production ? edema jaundice, possible
  hepatosplenomegaly, possible neurological sx

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Prevention

• Blood type and antibody screen at first prenatal
  visit (USPSTF A recommendation)
• Repeat screen at 24-28 wks gest unless FOB known
  Rh(D)- (USPSTF B recommendation)
• Administer 300mcg Rh(D) immunoglobulin to
  unsensitized women at 24-28 wks gest
• If Rh(D) (or weakly ) infant delivered, give
  another IG dose within 72 hours
• Unless FOB known Rh(D)-, give IG after
  amniocentesis, SAB or TOP
• Insufficient evidence for giving IG for other
  procedures (USPSTF). However, ACOG recommends for
  CV sampling, fetal blood sampling (A), and
  consider IG admin for threatened abortion,
  2nd/3rd trimester antenatal bleeding, external
  cephalic version, abdominal trauma (C).

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For the Alloimmunized Patient

• See flowchart
• Indication for high-risk OB, or MFM specialist
  referral

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Sources

• American College of Obstetricians and
  Gynecologists (ACOG). Prevention of Rh D
  alloimmunization. Washington (DC) American
  College of Obstetricians and Gynecologists
  (ACOG) 1999 May. 8 p. (ACOG practice bulletin
  no. 4).
• Hemolytic disease of the newborn.
  dynaweb.ebscohost.com.
• Moise Jr., Kenneth. Pathogenesis and prenatal
  diagnosis of Rhesus (Rh) alloimmunization.
  www.uptodate.com.
• U.S. Preventive Services Task Force (USPSTF).
  Screening for Rh(D) incompatibility
  recommendation statement. Rockville (MD) Agency
  for Healthcare Research and Quality (AHRQ) 2004
  Feb. 4 p.