ACDM	California College of Midwives
Sept 1999	Principles of Mother-Friendly Childbearing Services

Laboratory and Antepartal Diagnostic Test
and Procedures

Routine and incidential laboratory test for mother and ultrasound screening for fetus: (adapted from UCSF Medical Center - Perinatal Pathway)

• 6-12 wks -- CBC, Blood Type/Rh, AB screen, HbsAg, RPR, Rubella Titre, Urine culture /screen   // Optional /as indicated:   PPD, PAP, GC culture, Chlamydia, Hgb electrophoresis, HIV, Taysachs, CVS, Sono, Urine Tox

• 15-18 wks --  Optional/as indicated:  Triple marker, Amnio, Sono, Early GLXP

• 24-28 wks --- GLXP/CBC    Optional / as indicated: GTT 3hr, AB screen if Rh neg, Rhogam @ 28 wks if Rh neg

• 41-43 wks -- AFI, NST, BPP, instruct mother regarding kick counts

---

GBS - Risk protocols (instead of routine GBS culture at 36 wks) are most freguently used by community-based midwives as well as recommended by ACOG Guidelines. Any pregnant woman who previously had a baby with GBS disease or who has a urinary tract infection caused by GBS should to offered access to antibiotics during labor.  In addition all mothers who develop risk factors during labor are advised to have antibiotics intrapartum. Those risk factors are:

fever during labor
rupture of membranes 18 hours or more before delivery
labor or rupture of membranes before 37 weeks ("preterm")

Currently (September 1999) only IV antibiotic treatment has an approved protocol. However midwives in several locations having be offering PO antibiotics or IM injections. 

(See GBS Informed Consent)

An additional management technique in those places with access to the new one hour test (Strep B OIA tm culture) may want to consider the  GBS protocol from Stanford/UCSF to prevent early onset neonatal group B streptococcal sepsis while reducing exposure of uninfected babies to unnecessary antibiotics ( can be done during labor, test resutls available in one hour): 

For mothers with risk factors, screening at onset of labor or  SROM, vaginal culture with Strep B OIA tm, is recommended to detect moderate to heavy  colonization with group B streptococcus. Test is performed by using a sterile CuluretteII swab with sampling obtained from lower 1/3 of vagina. Swabs must have ampule of holding media broken. Swabs with charcoal or gel medium do not work. Cultures must be processes within 72 hrs.  Results are available within one hour.

This permits the GBS positive mother to be appropriately treated while not subjecting GBS negative mothers and their babies to unnecessary exposure of antibiotics.  [1999 study by Drs Benitz, Gould, & Druzin at LPCH/Stanford UCSF to be published in the peer-review journal Pediatrics this summer]

• Under this strategy, women delivering between 31-37 weeks who would all receive prophylaxis under the CDC guidelines are not given prophylaxis if the Strep B OIA tm is negative
  
  Maternal Prophylaxis during active labor if GBS+: 
          Ampicillin 2 g IV once, then 1 g IV, q4hr until delivery or
          Penicillin G 5 million Units IV once, then 2.5 million Units IV q4hrs
          until delivery
  
  If penicillin-allergic:
          Clindamycin 900 mg IV q8hrs until delivery
          Erythromycim 500 mg IV q6hrs until delivery

• Supplemental Neonatal Prophylaxis -- Maternal allergy to penicillin is not a contraindication to treatment of infant:
  Ampicillin 50mg/kg/dose IM  q12 hrs beginning stat after birth and continuing until discharge, up to a maximum of 4 doses OR
  Penicillin 100,000 units IM once immediately after birth

• In addition to these prophylactic measures, intrapartum antibiotic therapy and a complete diagnostic evaluation and empiric treatment of the infant is recommended if there is:
  
  GBS bacteriuria during the current pregnancy
  A sibling with early-onset GBS infection
  Chorioamniotitis
  Preterm (EGA < 37 weeks) premature (before onset of labor) rupture of membranes (PPROM)