Cause:Idiopathic usually; chromosomal abnormalities; autoantibodies; or structural (eg, uterine septum, fibroids)

15-20% of all pregnancies. Most at 10 weeks (Nejm 1988;319:189). 1/3 have chromosome abnormalities, 1/2 are blighted ova. Late (>20 wk) assoc w Leiden factor V, prothrombin gene mutations (Nejm 2000;343:1015), and antiphospholipid antibodies (Lupus anticoagulant, anti-ß₂ glycoprotein I antibodies, or anticardiolipin antibodies) (Deep Venous Thrombophlebitis) (Nejm 2002;346:752)

Incr (× 1.4-1.8) by smoking and cocaine use (Nejm 1999;340:333); with coffee use (Nejm 2000;343:1839; 1999;341:1688); with video display terminals (Nejm 1991;324:727); w NSAIDs, esp in 3rd trimester; w low folate levels (Jama 2002;288:1867)

Sx:Crampy pain, spontaneous vaginal bleeding; passage of tissue means fetal death

Si:Open cervical os and/or tissue means inevitably will abort

When threatened (bleed), 50% will eventually lose pregnancy

Sepsis, uterine necrosis leading to myoglobinuria and ATN, DIC; significant depression (Jama 1997;277:383), onset within 1 mo, esp if childless (20+% incidence) or PMH/o depression (50%) incidence

r/o ectopic, molar pregnancy, self-induced abortion

Lab:Chromosomal studies if 3 spontaneous abortions looking for balanced translocation

Rx:

Emotional support

Misoprostol 800 µgm vaginally, repeat day 3 if ab not complete; 84% need no D&C (Nejm 2005;353:761—but what % wouldn't need the misoprostol?)

D&C if

• Heavy bleeding;
• >8-wk gestation, since will bleed longer and more heavily;
• Is 2nd SAB, to r/o intrauterine anatomic abnormalities; or if
• Infected

Give Rhogam if Rh negative.

in lupus anticoagulant pts, heparin (Nejm 2002;346:752); ASA + prednisone prophylaxis no help (Nejm 1997;337:149)