- Email: [email protected]
Timing and complications of abdominal cerclage: Preconceptual vs antepartum placement
S154 SMFM Abstracts 544
FORCEPS VS. VACUUM: WHICH IS ASSOCIATED WITH THE GREATEST MORBIDITY? AARON B. CAUGHEY1, PER SANDBERG2, MARYA ZLATNIK1, JULIAN T. PARER1, MARIPAULE THIET1, RUSSELL K. LAROS JR1, 1University of California, San Francisco, Obstetrics, Gynecology and Reproductive Sciences, San Francisco, California, 2 California Pacific Medical Center, Obstetrics and Gynecology, San Francisco, California OBJECTIVE: To compare perinatal outcomes between forceps and vacuum assisted deliveries. Our hypothesis was that the force vectors achieved in forceps delivery will lead to fewer shoulder dystocia, but greater perineal lacerations. STUDY DESIGN: This is a retrospective cohort study of 4120 term, cephalic, singleton, operative vaginal deliveries at a single institution. Outcomes examined included rates of shoulder dystocia, perineal and cervical lacerations, and neonatal trauma. Potential confounders including maternal age, birthweight, ethnicity, parity, gestational age, station at delivery, episiotomy, attending physician, anesthesia, and lengths of 1st and 2nd stages of labor were controlled for using multivariate logistic regression. RESULTS: In the study population, there were 2045 (49.6%) forceps and 2075 (50.4%) vacuum assisted deliveries. Of note, the rate of shoulder dystocia was higher among women undergoing vacuum assisted delivery (3.5% vs. 1.5%, P! .001). Other differences are reported in the table below. These differences in perinatal complication rate persisted when controlling for the confounders listed above with adjusted odds ratio for shoulder dystocia being 3.05 (95% CI 1.85– 5.04), and 3rd or 4th degree lacerations being 0.65 (95% CI 0.55–0.75) when comparing vacuum to forceps. CONCLUSION: Vacuum assisted vaginal birth is more often associated with shoulder dystocia and cephalohematoma. Forceps delivery is more often associated with 3rd and 4th degree perineal lacerations as well as cervical lacerations. These differences in complications rates should be considered among other factors when determining the optimal mode of delivery. Outcomes
Forceps
Vacuum
P value
Shoulder dystocia 3rd/4th degree Cervical lac Birth trauma* Cephalo- hematoma
1.5% 36.9% 3.0% 1.7% 4.5%
3.5% 26.8% 1.5% 2.1% 14.8%
! .001 ! .001 ! .001 .389 ! .001
546
TIMING AND COMPLICATIONS OF ABDOMINAL CERCLAGE: PRECONCEPTUAL VS ANTEPARTUM PLACEMENT NICOLE SMITH1, THOMAS MCELRATH1, AVIVA LEEPARRITZ2, 1Brigham and Women’s Hospital, Obstetrics and Gynecology, Boston, Massachusetts, 2Boston University, Obstetrics and Gynecology, Boston, Massachusetts OBJECTIVE: Current literature supports the efficacy of abdominal cerclage, while reporting varying rates of complications. However, prior studies do not distinguish between preconceptual and antepartum placement. This study compares rates of surgical and pregnancy-related complications in these two groups. STUDY DESIGN: A retrospective case series was performed, including all women undergoing abdominal cerclage placement at Brigham & Women’s Hospital from 1998-2003. We compared pregnancy history, intraoperative complications, and pregnancy outcome. Fisher’s exact and Student’s T tests were used for all comparisons. RESULTS: A total of 28 women underwent abdominal cerclage placement. Results are summarized in the Table. Comparison of indications and outcomes
Indications for cerclage Prior pregnancy of !24 wk Prior vaginal cerclage Prior cervical surgery Operative complications Need for transfusion Post op temp O 100.4 Rupture of membranes Pregnancy loss within 7 d Pregnancy outcomes Number achieving pregnancy Cunently pregnant GA O36 wk Infants requiring NICU stay Second trimester loss Cervical dilation despite cerclage
* Birth trauma includes: skull fx, clavicle fx, erbs palsy, intracranial hemorrhage, and facial nerve palsy.
Preconceptual N = 19
Antepartum N=9
68%(13) 68%(13) 21%(4)
67%(6) 56%(5) 33%(3)
.99 .67 .64
0 0 N/A N/A
1 1 1 2
.33 .33 -
9 2 5 0 0 0
9 0 6 0 3 1
.01 .66 1.00 .07 .30
P value
CONCLUSION: This case review suggests that pregnancy complications resulting in second trimester loss were more common with antepartum placement of abdominal cerclage. While preconceptual cerclage carries less surgical risk, not all women will go on to subsequent pregnancy, thus some laparotomies may be performed unnecessarily. Patients must be counseled as to the higher potential for fetal risk associated with antepartum placement compared with the risk of unnecessary laparotomy and hospitalization with preconceptual procedures.
545
OBSTETRIC OUTCOME OF SECOND DELIVERY FOLLOWING FIRST DELIVERY OF A MACROSOMIC INFANT (O4.5KG) RHONA MAHONY1, MICHAEL E. FOLEY1, LESLIE DALY2, COLM O’HERLIHY1, 1University college Dublin, Obstetrics and Gynaecology, Dublin, Ireland, 2University College Dublin, Public Health Medicine & Epidemiology, Dublin, Ireland, Ireland OBJECTIVE: Fetal macrosomia is associated with dystocia and increased maternal and perinatal morbidity and predisposes to macrosomia in subsequent pregnancies. Our aim was to evaluate obstetric outcome of second delivery in women whose first baby was macrosomic. STUDY DESIGN: The obstetric outcome of second delivery of primiparous women whose first infant weighed >4.5 kg, delivering during the four years 1997-2000 was analyzed. A control group of 300 consecutive women delivering a first infant weighing 3.0-3.5 kg in 1997 was used for comparison. RESULTS: Among 13,020 primiparas delivering during the study period, 301 (2.6%) infants were macrosomic. A similar proportion in both groups- 52% of macrosomics and 57% of controls- returned for second delivery before 2004. Compared with controls, first macrosomic deliveries were characterised by higher rates of instrumental (23% vs 16%; P = ! .01) and intrapartum cesarean delivery (23% vs 10.7%; P ! .01). At second delivery, recurrence of macrosomia was 102/156 (65%). 27 (9%) compared with 8 (3%) controls underwent prelabor cesarean and the intrapartum cesarean rate was significantly greater than controls (14/129, [10.7%] vs 7/164 [4.2%], P ! .05). Among the previous macrosomic group 103/104 women (99%) who labored following first vaginal delivery had a subsequent vaginal delivery compared with 11/25 (44%) who labored after primiparous cesarean delivery (P ! .001). Similarly, 119/123 (97%) of controls had a second vaginal delivery following primiparous vaginal delivery compared with 7/10 (70%) following primiparous cesarean. Recurrence rates of macrosomia were similar (65% vs 64%) in vaginal and cesarean deliveries. CONCLUSION: First vaginal delivery of a macrosomic infant was associated with a high (99%) incidence of second vaginal delivery, despite a two-thirds recurrence of macrosomia. Women who underwent primiparous cesarean with fetal macrosomia had a high risk of repeat intrapartum cesarean delivery whether macrosomia recurred or not.
547
EVALUATION OF THE MAXIMAL PRESSURE EXERTED BY OBSTETRIC FORCEPS ON A FETAL HEAD MANNEQUIN MODEL ALFREDO GEI1, KIMBERLY HENNAN2, VICTOR SUAREZ3, GARY HANKINS4, 1University of Texas Medical Branch at Galveston, Obstetrics and Gynecology, Galveston, Texas, 2University of Texas Medical Branch at Galveston, Obstetrics, Gynecology and Reproductive Sciences, Galveston, Texas, 3University of Texas Medical Branch at Galveston, Obstetrics and Gyneclogy, Galveston, Texas, 4University of Texas Medical Branch at Galveston, Obstretics & Gynecology, Galveston, Texas OBJECTIVE: To quantify the maximal pressure exerted by the application of different forceps on a fetal head model. STUDY DESIGN: Planar impressions of the following forceps blades were obtained: De-Lee Simpson (DLS), Simpson-Luikart (SL), Kielland-Luikart (KL), Naegele (N), Tucker-McLane (TML) and Piper (P). Corresponding pieces of pressure-sensitive paper (350-1400 psi and 1400-7100 psi) were cut with 1 cm margins from the blade’s edge and taped to the blade’s inner surface from the exterior portion of the forceps. For standardization, a single application was performed for 10 seconds by one of the authors. In all cases a symmetric bifronto-biparietal grip was used with the plane of the shanks kept at 2.5 cm below the anterior edge of the posterior fontanel and the handle closed to full apposition. The developing sheets were separated from the blades and scanned with a Fujifilm scanner to calculate the area of contact, maximal pressure, average force and a histogram of pressure. Comparisons were made between different instruments, fenestrated and non-fenestrated and right and left blades using Student’s t test, one way ANOVA and Tukey tests as appropriate. Significance: P ! .05. RESULTS: Two sets of impressions per forceps per film were obtained. The area of contact between the blades and the head (above the film’s range of detection) averaged 0.06 sq. The highest pressure was exerted by the TM forceps (1531.4 G 27.4 psi) and the lowest by the LK (987.3 G 118.1 psi). The LK forceps generated significantly lower pressure than the N (P = .01), P (P = .02) and TM (P = .01) forceps. No differences were noted between fenestrated and non fenestrated forceps, right or left blades or between different forceps regarding average or maximal pressure, average force or area of contact. No measureable impressions were recorded with the highest sensitivity paper (14007100 psi). CONCLUSION: Biparieto-malar symmetric applications of commonly used forceps on a fetal head mannequin model result in distal points of pressure reaching or exceeding 1000 psi.
FORCEPS VS. VACUUM: WHICH IS ASSOCIATED WITH THE GREATEST MORBIDITY? AARON B. CAUGHEY1, PER SANDBERG2, MARYA ZLATNIK1, JULIAN T. PARER1, MARIPAULE THIET1, RUSSELL K. LAROS JR1, 1University of California, San Francisco, Obstetrics, Gynecology and Reproductive Sciences, San Francisco, California, 2 California Pacific Medical Center, Obstetrics and Gynecology, San Francisco, California OBJECTIVE: To compare perinatal outcomes between forceps and vacuum assisted deliveries. Our hypothesis was that the force vectors achieved in forceps delivery will lead to fewer shoulder dystocia, but greater perineal lacerations. STUDY DESIGN: This is a retrospective cohort study of 4120 term, cephalic, singleton, operative vaginal deliveries at a single institution. Outcomes examined included rates of shoulder dystocia, perineal and cervical lacerations, and neonatal trauma. Potential confounders including maternal age, birthweight, ethnicity, parity, gestational age, station at delivery, episiotomy, attending physician, anesthesia, and lengths of 1st and 2nd stages of labor were controlled for using multivariate logistic regression. RESULTS: In the study population, there were 2045 (49.6%) forceps and 2075 (50.4%) vacuum assisted deliveries. Of note, the rate of shoulder dystocia was higher among women undergoing vacuum assisted delivery (3.5% vs. 1.5%, P! .001). Other differences are reported in the table below. These differences in perinatal complication rate persisted when controlling for the confounders listed above with adjusted odds ratio for shoulder dystocia being 3.05 (95% CI 1.85– 5.04), and 3rd or 4th degree lacerations being 0.65 (95% CI 0.55–0.75) when comparing vacuum to forceps. CONCLUSION: Vacuum assisted vaginal birth is more often associated with shoulder dystocia and cephalohematoma. Forceps delivery is more often associated with 3rd and 4th degree perineal lacerations as well as cervical lacerations. These differences in complications rates should be considered among other factors when determining the optimal mode of delivery. Outcomes
Forceps
Vacuum
P value
Shoulder dystocia 3rd/4th degree Cervical lac Birth trauma* Cephalo- hematoma
1.5% 36.9% 3.0% 1.7% 4.5%
3.5% 26.8% 1.5% 2.1% 14.8%
! .001 ! .001 ! .001 .389 ! .001
546
TIMING AND COMPLICATIONS OF ABDOMINAL CERCLAGE: PRECONCEPTUAL VS ANTEPARTUM PLACEMENT NICOLE SMITH1, THOMAS MCELRATH1, AVIVA LEEPARRITZ2, 1Brigham and Women’s Hospital, Obstetrics and Gynecology, Boston, Massachusetts, 2Boston University, Obstetrics and Gynecology, Boston, Massachusetts OBJECTIVE: Current literature supports the efficacy of abdominal cerclage, while reporting varying rates of complications. However, prior studies do not distinguish between preconceptual and antepartum placement. This study compares rates of surgical and pregnancy-related complications in these two groups. STUDY DESIGN: A retrospective case series was performed, including all women undergoing abdominal cerclage placement at Brigham & Women’s Hospital from 1998-2003. We compared pregnancy history, intraoperative complications, and pregnancy outcome. Fisher’s exact and Student’s T tests were used for all comparisons. RESULTS: A total of 28 women underwent abdominal cerclage placement. Results are summarized in the Table. Comparison of indications and outcomes
Indications for cerclage Prior pregnancy of !24 wk Prior vaginal cerclage Prior cervical surgery Operative complications Need for transfusion Post op temp O 100.4 Rupture of membranes Pregnancy loss within 7 d Pregnancy outcomes Number achieving pregnancy Cunently pregnant GA O36 wk Infants requiring NICU stay Second trimester loss Cervical dilation despite cerclage
* Birth trauma includes: skull fx, clavicle fx, erbs palsy, intracranial hemorrhage, and facial nerve palsy.
Preconceptual N = 19
Antepartum N=9
68%(13) 68%(13) 21%(4)
67%(6) 56%(5) 33%(3)
.99 .67 .64
0 0 N/A N/A
1 1 1 2
.33 .33 -
9 2 5 0 0 0
9 0 6 0 3 1
.01 .66 1.00 .07 .30
P value
CONCLUSION: This case review suggests that pregnancy complications resulting in second trimester loss were more common with antepartum placement of abdominal cerclage. While preconceptual cerclage carries less surgical risk, not all women will go on to subsequent pregnancy, thus some laparotomies may be performed unnecessarily. Patients must be counseled as to the higher potential for fetal risk associated with antepartum placement compared with the risk of unnecessary laparotomy and hospitalization with preconceptual procedures.
545
OBSTETRIC OUTCOME OF SECOND DELIVERY FOLLOWING FIRST DELIVERY OF A MACROSOMIC INFANT (O4.5KG) RHONA MAHONY1, MICHAEL E. FOLEY1, LESLIE DALY2, COLM O’HERLIHY1, 1University college Dublin, Obstetrics and Gynaecology, Dublin, Ireland, 2University College Dublin, Public Health Medicine & Epidemiology, Dublin, Ireland, Ireland OBJECTIVE: Fetal macrosomia is associated with dystocia and increased maternal and perinatal morbidity and predisposes to macrosomia in subsequent pregnancies. Our aim was to evaluate obstetric outcome of second delivery in women whose first baby was macrosomic. STUDY DESIGN: The obstetric outcome of second delivery of primiparous women whose first infant weighed >4.5 kg, delivering during the four years 1997-2000 was analyzed. A control group of 300 consecutive women delivering a first infant weighing 3.0-3.5 kg in 1997 was used for comparison. RESULTS: Among 13,020 primiparas delivering during the study period, 301 (2.6%) infants were macrosomic. A similar proportion in both groups- 52% of macrosomics and 57% of controls- returned for second delivery before 2004. Compared with controls, first macrosomic deliveries were characterised by higher rates of instrumental (23% vs 16%; P = ! .01) and intrapartum cesarean delivery (23% vs 10.7%; P ! .01). At second delivery, recurrence of macrosomia was 102/156 (65%). 27 (9%) compared with 8 (3%) controls underwent prelabor cesarean and the intrapartum cesarean rate was significantly greater than controls (14/129, [10.7%] vs 7/164 [4.2%], P ! .05). Among the previous macrosomic group 103/104 women (99%) who labored following first vaginal delivery had a subsequent vaginal delivery compared with 11/25 (44%) who labored after primiparous cesarean delivery (P ! .001). Similarly, 119/123 (97%) of controls had a second vaginal delivery following primiparous vaginal delivery compared with 7/10 (70%) following primiparous cesarean. Recurrence rates of macrosomia were similar (65% vs 64%) in vaginal and cesarean deliveries. CONCLUSION: First vaginal delivery of a macrosomic infant was associated with a high (99%) incidence of second vaginal delivery, despite a two-thirds recurrence of macrosomia. Women who underwent primiparous cesarean with fetal macrosomia had a high risk of repeat intrapartum cesarean delivery whether macrosomia recurred or not.
547
EVALUATION OF THE MAXIMAL PRESSURE EXERTED BY OBSTETRIC FORCEPS ON A FETAL HEAD MANNEQUIN MODEL ALFREDO GEI1, KIMBERLY HENNAN2, VICTOR SUAREZ3, GARY HANKINS4, 1University of Texas Medical Branch at Galveston, Obstetrics and Gynecology, Galveston, Texas, 2University of Texas Medical Branch at Galveston, Obstetrics, Gynecology and Reproductive Sciences, Galveston, Texas, 3University of Texas Medical Branch at Galveston, Obstetrics and Gyneclogy, Galveston, Texas, 4University of Texas Medical Branch at Galveston, Obstretics & Gynecology, Galveston, Texas OBJECTIVE: To quantify the maximal pressure exerted by the application of different forceps on a fetal head model. STUDY DESIGN: Planar impressions of the following forceps blades were obtained: De-Lee Simpson (DLS), Simpson-Luikart (SL), Kielland-Luikart (KL), Naegele (N), Tucker-McLane (TML) and Piper (P). Corresponding pieces of pressure-sensitive paper (350-1400 psi and 1400-7100 psi) were cut with 1 cm margins from the blade’s edge and taped to the blade’s inner surface from the exterior portion of the forceps. For standardization, a single application was performed for 10 seconds by one of the authors. In all cases a symmetric bifronto-biparietal grip was used with the plane of the shanks kept at 2.5 cm below the anterior edge of the posterior fontanel and the handle closed to full apposition. The developing sheets were separated from the blades and scanned with a Fujifilm scanner to calculate the area of contact, maximal pressure, average force and a histogram of pressure. Comparisons were made between different instruments, fenestrated and non-fenestrated and right and left blades using Student’s t test, one way ANOVA and Tukey tests as appropriate. Significance: P ! .05. RESULTS: Two sets of impressions per forceps per film were obtained. The area of contact between the blades and the head (above the film’s range of detection) averaged 0.06 sq. The highest pressure was exerted by the TM forceps (1531.4 G 27.4 psi) and the lowest by the LK (987.3 G 118.1 psi). The LK forceps generated significantly lower pressure than the N (P = .01), P (P = .02) and TM (P = .01) forceps. No differences were noted between fenestrated and non fenestrated forceps, right or left blades or between different forceps regarding average or maximal pressure, average force or area of contact. No measureable impressions were recorded with the highest sensitivity paper (14007100 psi). CONCLUSION: Biparieto-malar symmetric applications of commonly used forceps on a fetal head mannequin model result in distal points of pressure reaching or exceeding 1000 psi.