EFFECTS OF LEBOYER CHILDBIRTH ON LEFT-SYSTOLIC-TIME AND RIGHT-SYSTOLIC-TIME INTERVALS IN HEALTHY TERM NEONATES

The Leboyer birth method requires that the newborn infant is placed on the mothers abdomen and the cord is clamped when it stops pulsating. Since late cord-clamping may result in marked hypervolemia and polycyt hemia of the neonate, we studied right and left ventricular systolic t ime intervals by means of pulsed-Doppler echocardiography. Left and ri ght ventricular preejection periods (LPEP, RPEP), right time peak velo city (RTPV), left and right ventricular ejection times (LVET, RVET), a nd ratio of RTPV/RVET((c)) corrected for heart rate were studied in 15 fullterm neonates with early (< 10 s) cord clamping and in 15 full-te rm neonates delivered according to Leboyer (cord clamping after 3 min) on day 1 (2-4 h after birth) and day 5. After Leboyer birth hematocri t was significantly increased on day 1 (0.61 +/- 0.06 vs. 0.53 +/- 0.0 7) and on day 5 (0.57 +/- 0.02 vs. 0.50 +/- 0.07). Blood pressure was similar in bath groups and increased by about 10% from day 1 to day 5. LVET and RVET were not affected by the mode of placental transfusion, thereby suggesting normal left and right ventricular function after L eboyer birth. The LPEP/LVET (0.36 +/- 0.09 vs. 0.30 +/- 0.08) and RPEP /RVET ratio (0.41 +/- 0.11 vs. 0.33 +/- 0.08) were significantly highe r in the Leboyer group (p < 0.05) compared to the early cord clamped g roup suggesting higher systemic and pulmonary resistance. RPEP decreas ed significantly by 17% in the control group from day 1 to day 5 (p < 0.05), but did not change in the Leboyer group. In the Leboyer group R PEP/RVET ratio decreased significantly from day 1 to day 5, whereas th e control values did not change during the first five days. RTPV : RVE T((c)) is inversely related to pulmonary artery pressure. A normal rat io is > 0.35, or greater. Mean ratio of RTPV : RVET((c)) was significa ntly lower in the Leboyer group (0.31 +/- 0.08) on day 1 compared to t he control group (0.41 +/- 0.09; p < 0.05), but did not differ on day 5. The results suggest that Leboyer delivery was associated with trans iently increased pulmonary and systemic resistance, whereas right and left ventricular functions were not affected. This may be explained by increased blood viscosity due to increased hematocrit.