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142: Placental predictors of adverse outcomes in monochorionic twins
www.AJOG.org
Clinical Obstetrics, Neonatology, Physiology-Endocrinology
STUDY DESIGN: Placentas from all multiple gestations delivered within one medical system from 1996-2003 were sent to a central placental pathology laboratory. We describe findings in those proven to be MC gestations. Data on obstetrical outcomes and complications was collected. Detailed placental vascular anatomy was analyzed via dye injection studies. RESULTS: Of 288,000 consecutive deliveries, 658 placentas were monochorionic (0.003%). Of those, the incidence of monoamniotic and conjoined twins was 4% and 0.6% respectively. The incidence of higherorder multiples with an MC pair was 4.7%. The mean GA at delivery was 34.3 weeks, with 20% born at ⬍32 wks and 11% at ⬍28 wks. The mean birth weights (BW) for the larger and smaller twins were 2357g and 2069g, respectively, with a mean BW discordance of 13%. BW discordance 20% was observed in 25%. Very low birth weight (1500 gm) was seen in the larger twin in 14% and in the smaller twin in 20%. TTTS and TRAP complicated 9.7% and 1.2% of pregnancies, respectively. IUFD of one twin was observed in 2.6% and of both twins in 6.4%. Discordant structural abnormalities were identified in 1.5%. CONCLUSION: This large, unselected, pathology-proven consecutive cohort represents the largest series to date studying the distribution of outcomes and natural history of MC twins. The incidence of major complications is lower than previously reported.
Poster Session I
143 Maternal outcomes by labor onset type Jennifer Bailit1, Jun Zhang2, Victor Hugo Gonzalez Quintero3, Kimberly Gregory4, Isabelle Wilkins5, Mildred M. Ramirez6, Uma Reddy7, Paul Vanveldhuisen8, Ronald Burkman9, Ware Branch10, Matthew Hoffman11, Shoshana Haberman12, Michelle Kominiarek13, Helain Landy14, Christos Hatjis15, James Troendle16 1 MetroHealth, Case Western Reserve University, Cleveland, Ohio, 2Division of Epidemiology, Statistics and Prevention Research, NICHD, NIH, Bethesda, Maryland, 3University of Miami, Dept of Ob/Gyn-MFM Division, Miami, Florida, 4Cedars-Sinai Medical Center, Los Angeles, California, 5University of Illinois at Chicago, Illinois, 6University of Texas Health Science Center at Houston, Obstetrics, Gynecology and Reproductive Sciences, Houston, Texas, 7NICHD, NIH, Bethesda, Maryland, 8Emmes Corporation, Rockville, Maryland, 9Tufts University, Baystate Medical Center, Springfield, Massachusetts, 10Intermountain Health and University of Utah, Obstetrics and Gynecology, Salt Lake City, Utah, 11Christiana Hospital, Newark, Delaware, 12Maimonides Medical Center, Brooklyn, New York, 13Indiana University, Indianapolis, Indiana, 14Georgetown University Hospital/Medstar Health, Washington, District of Columbia, 15 Children’s Hospital Medical Center of Akron, Akron, Ohio, 16Division of Epidemiology, Statistics and Prevention Research, NICHD, NIH, Maryland
0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.156
OBJECTIVE: To determine maternal outcomes by labor onset type at
142 Placental predictors of adverse outcomes in monochorionic twins
STUDY DESIGN: The Consortium on Safe Labor retrospectively col-
term.
1
2
Larry Rand , Rebecca Smith-Bindman , Payam Saadai3, Geoffrey Machin4, Vickie Feldstein5 1
University of California, San Francisco, Obstetrics and Gynecology; Surgery, San Francisco, California, 2University of California, San Francisco, Epidemiology and Statistics, California, 3University of California, San Francisco, San Francisco, California, 4Mount Sinai Hospital Toronto, Pathology, Toronto, Ontario, Canada, 5University of California, San Francisco, Radiology, San Francisco, California
OBJECTIVE: Monochorionic (MC) twins are at increased risk for complications, including twin-twin transfusion syndrome (TTTS) and in utero fetal demise (IUFD). Factors associated with these outcomes are not fully understood. Associations between cord insertions (CI), inter-twin vascular connections, specifically arterio-arterial anastomoses (AAs), and these complications were studied. STUDY DESIGN: Placentas and obstetrical outcome data from all consecutive twin gestations between 1996-2003 were collected within a large medical system. Placental evaluation of every MC placenta was performed using vascular dye injection studies and outcomes were evaluated by univariate logistic regression analysis. RESULTS: Of 658 MC pregnancies, 9.7% were complicated by TTTS. IUFD of 1 fetus was seen in 2.6% and of both fetuses in 6.4% of cases. Compared to cases with central CI, risk of TTTS was increased if either the smaller twin (OR 4.7, CI 2.2-9.7, p⬍0.0001) or the larger twin (OR 5.9, CI 2.4-14.7, p⫽0.0002) had a velamentous insertion. Risk was even higher if both had velamentous insertions (OR 15.6, CI 3.6-68, p⫽0.0003). Likelihood of IUFD was 3%, 8% and 14% when CI of the smaller twin was central, marginal, or velamentous, respectively. In combination, the highest risk for ⬎1 fetal death (19%) occurred when the larger twin had a velamentous, and the smaller twin a marginal or velamentous insertion. TTTS was significantly more likely when no AA was found (OR 16.7, CI 7.7-13.3, p⬍0.0001). Absence of an AA was associated with 39% risk of TTTS. Presence of an AA reduced the risk to 4%. Absence of an AA was associated with 28% risk of IUFD (one or both fetuses). Presence of an AA reduced this risk to 4% (p⬍0.0001). CONCLUSION: This study confirms that CI sites and inter-twin vascular connections, features potentially identifiable by prenatal ultrasound, are important predictors related to outcomes of MC twin pregnancies. Velamentous insertion and absence of an AA are associated with significant increased risk of TTTS and IUFD.
lected electronic medical records from 10 institutions on 156,786 deliveries from 2002-08. Deliveries were divided by labor onset type (spontaneous, elective induction, indicated induction, unlabored cesarean). Maternal outcomes at term were calculated by labor onset type. RESULTS: Unadjusted maternal outcomes varied by labor onset type (p⬍.001 figures). Adjusted for preeclampsia, chronic hypertension, diabetes, premature rupture of membranes, and GBS ⫹, there were no differences between elective induction and spontaneous labor for endometritis (OR 1.1 95%CI 0.6,2.1) or ICU admission (OR 0.68 95% CI 0.42,1.1). However, hysterectomy was 3.4 times more likely with elective induction vs. spontaneous labor (1.5-7.8 95% CI).
CONCLUSION: Elective induction at term has a substantial risk of hys-
terectomy when compared to spontaneous labor. 0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.158
0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.157 Supplement to DECEMBER 2009 American Journal of Obstetrics & Gynecology
S67
Clinical Obstetrics, Neonatology, Physiology-Endocrinology
STUDY DESIGN: Placentas from all multiple gestations delivered within one medical system from 1996-2003 were sent to a central placental pathology laboratory. We describe findings in those proven to be MC gestations. Data on obstetrical outcomes and complications was collected. Detailed placental vascular anatomy was analyzed via dye injection studies. RESULTS: Of 288,000 consecutive deliveries, 658 placentas were monochorionic (0.003%). Of those, the incidence of monoamniotic and conjoined twins was 4% and 0.6% respectively. The incidence of higherorder multiples with an MC pair was 4.7%. The mean GA at delivery was 34.3 weeks, with 20% born at ⬍32 wks and 11% at ⬍28 wks. The mean birth weights (BW) for the larger and smaller twins were 2357g and 2069g, respectively, with a mean BW discordance of 13%. BW discordance 20% was observed in 25%. Very low birth weight (1500 gm) was seen in the larger twin in 14% and in the smaller twin in 20%. TTTS and TRAP complicated 9.7% and 1.2% of pregnancies, respectively. IUFD of one twin was observed in 2.6% and of both twins in 6.4%. Discordant structural abnormalities were identified in 1.5%. CONCLUSION: This large, unselected, pathology-proven consecutive cohort represents the largest series to date studying the distribution of outcomes and natural history of MC twins. The incidence of major complications is lower than previously reported.
Poster Session I
143 Maternal outcomes by labor onset type Jennifer Bailit1, Jun Zhang2, Victor Hugo Gonzalez Quintero3, Kimberly Gregory4, Isabelle Wilkins5, Mildred M. Ramirez6, Uma Reddy7, Paul Vanveldhuisen8, Ronald Burkman9, Ware Branch10, Matthew Hoffman11, Shoshana Haberman12, Michelle Kominiarek13, Helain Landy14, Christos Hatjis15, James Troendle16 1 MetroHealth, Case Western Reserve University, Cleveland, Ohio, 2Division of Epidemiology, Statistics and Prevention Research, NICHD, NIH, Bethesda, Maryland, 3University of Miami, Dept of Ob/Gyn-MFM Division, Miami, Florida, 4Cedars-Sinai Medical Center, Los Angeles, California, 5University of Illinois at Chicago, Illinois, 6University of Texas Health Science Center at Houston, Obstetrics, Gynecology and Reproductive Sciences, Houston, Texas, 7NICHD, NIH, Bethesda, Maryland, 8Emmes Corporation, Rockville, Maryland, 9Tufts University, Baystate Medical Center, Springfield, Massachusetts, 10Intermountain Health and University of Utah, Obstetrics and Gynecology, Salt Lake City, Utah, 11Christiana Hospital, Newark, Delaware, 12Maimonides Medical Center, Brooklyn, New York, 13Indiana University, Indianapolis, Indiana, 14Georgetown University Hospital/Medstar Health, Washington, District of Columbia, 15 Children’s Hospital Medical Center of Akron, Akron, Ohio, 16Division of Epidemiology, Statistics and Prevention Research, NICHD, NIH, Maryland
0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.156
OBJECTIVE: To determine maternal outcomes by labor onset type at
142 Placental predictors of adverse outcomes in monochorionic twins
STUDY DESIGN: The Consortium on Safe Labor retrospectively col-
term.
1
2
Larry Rand , Rebecca Smith-Bindman , Payam Saadai3, Geoffrey Machin4, Vickie Feldstein5 1
University of California, San Francisco, Obstetrics and Gynecology; Surgery, San Francisco, California, 2University of California, San Francisco, Epidemiology and Statistics, California, 3University of California, San Francisco, San Francisco, California, 4Mount Sinai Hospital Toronto, Pathology, Toronto, Ontario, Canada, 5University of California, San Francisco, Radiology, San Francisco, California
OBJECTIVE: Monochorionic (MC) twins are at increased risk for complications, including twin-twin transfusion syndrome (TTTS) and in utero fetal demise (IUFD). Factors associated with these outcomes are not fully understood. Associations between cord insertions (CI), inter-twin vascular connections, specifically arterio-arterial anastomoses (AAs), and these complications were studied. STUDY DESIGN: Placentas and obstetrical outcome data from all consecutive twin gestations between 1996-2003 were collected within a large medical system. Placental evaluation of every MC placenta was performed using vascular dye injection studies and outcomes were evaluated by univariate logistic regression analysis. RESULTS: Of 658 MC pregnancies, 9.7% were complicated by TTTS. IUFD of 1 fetus was seen in 2.6% and of both fetuses in 6.4% of cases. Compared to cases with central CI, risk of TTTS was increased if either the smaller twin (OR 4.7, CI 2.2-9.7, p⬍0.0001) or the larger twin (OR 5.9, CI 2.4-14.7, p⫽0.0002) had a velamentous insertion. Risk was even higher if both had velamentous insertions (OR 15.6, CI 3.6-68, p⫽0.0003). Likelihood of IUFD was 3%, 8% and 14% when CI of the smaller twin was central, marginal, or velamentous, respectively. In combination, the highest risk for ⬎1 fetal death (19%) occurred when the larger twin had a velamentous, and the smaller twin a marginal or velamentous insertion. TTTS was significantly more likely when no AA was found (OR 16.7, CI 7.7-13.3, p⬍0.0001). Absence of an AA was associated with 39% risk of TTTS. Presence of an AA reduced the risk to 4%. Absence of an AA was associated with 28% risk of IUFD (one or both fetuses). Presence of an AA reduced this risk to 4% (p⬍0.0001). CONCLUSION: This study confirms that CI sites and inter-twin vascular connections, features potentially identifiable by prenatal ultrasound, are important predictors related to outcomes of MC twin pregnancies. Velamentous insertion and absence of an AA are associated with significant increased risk of TTTS and IUFD.
lected electronic medical records from 10 institutions on 156,786 deliveries from 2002-08. Deliveries were divided by labor onset type (spontaneous, elective induction, indicated induction, unlabored cesarean). Maternal outcomes at term were calculated by labor onset type. RESULTS: Unadjusted maternal outcomes varied by labor onset type (p⬍.001 figures). Adjusted for preeclampsia, chronic hypertension, diabetes, premature rupture of membranes, and GBS ⫹, there were no differences between elective induction and spontaneous labor for endometritis (OR 1.1 95%CI 0.6,2.1) or ICU admission (OR 0.68 95% CI 0.42,1.1). However, hysterectomy was 3.4 times more likely with elective induction vs. spontaneous labor (1.5-7.8 95% CI).
CONCLUSION: Elective induction at term has a substantial risk of hys-
terectomy when compared to spontaneous labor. 0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.158
0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.157 Supplement to DECEMBER 2009 American Journal of Obstetrics & Gynecology
S67