Macrosomic trial of labor does not increase morbidity after prior cesarean delivery

OBJECTIVE: Despite AGOG opinion that ". . . a fetus with an estimated weight of more than 4000g are not contraindications to a trial of labor," paucity of information exists that comprehensively examines the morbidity associated with a trial of labor (TOL) in gravidas with one or more prior cesarean sections. Our study investigates this concept. METHODS: The records of all gravid women with at least one prior cesarean birth at University Hospital from July 1, 1970, to June 30, 1995 were reviewed. Macrosomia was defined as an infant weighing 4000g or more. Gomparisons were made between non-diabetic, macrosomic and non-macrosomic pregnancies weighing more than 1500g. RESULTS: 8742 women with one or more prior cesareans delivered during the study period. 4592 (53%) did not have a TOL. Of 4150 gravidas that had a TOL, 285 (7.0%) were macrosjfmic, 234 (82%) had VBAG, compared to 83% VBAG in non-macrosomic. Macrosomic vs non-macrosomic weight TOL outcome data (see Table): Apgar TOL # BW RDS <7 Seiz PND Hem Rupt Hysl Non-macrosomic 3865 3220 1.8 2.9 2 0.9 2.3 7 2.1 Macro 285 4303 2.9 1.9 0 0.3 4.5 0 1.0 < p < .01) CONCLUSION: Our series indicates that TOI- when the fetus is macrosomic, after one (or more) prior cesarean sections, is not associated with increased risk of maternal or perinatal morbidity or mortality. Since there is no difference in VBAC success rate, a TOL should be undertaken regardless of fetal weight in non-diabetic pregnancies.