- Email: [email protected]
580: How short is too short? The risk of preterm birth with inadequate birth spacing
Poster Session IV
Academic Issues, etc
www.AJOG.org CONCLUSION: Short interpregnancy intervals (IPI) are common
among women following their first delivery. Underserved women are at particularly high risk, as are women with a prior early preterm birth (EPTB). Disparities in short IPIs are most pronounced for very short intervals. Interventions to improve birth spacing may affect the risk of future adverse perinatal outcomes. In particular, attention should be directed toward women with prior EPTB, whose risk of subseqent adverse pregnancy outcomes is already higher at baseline. Adjusted odds of short interval by race/ethnicity
CONCLUSION: Compared to Caucasians, African American, Latina/
Hispanic, and Other non-Hispanic women with twins have higher risk of neonatal complications.
< 3 months White 1.00
< 6 months
< 12 months
< 18 months
1.00
1.00
1.00
0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.442
..........................................................................................................................................................................................
578 Number of prior cesarean delivery and perinatal outcomes: more is worse?
Hisp. 1.52 (1.33, 1.74) 1.36 (1.27, 1.46) 1.13 (1.09, 1.18) 1.05 (1.02, 1.09) ..........................................................................................................................................................................................
1
1
Asian 1.84 (1.54, 2.20) 1.80 (1.65, 1.90) 1.28 (1.22, 1.35) 1.06 (1.02, 1.11) .......................................................................................................................................................................................... 1
Yvonne Cheng , Sanae Nakagawa , Aaron Caughey 1
Black 1.44 (1.16, 1.79) 1.17 (1.04, 1.32) 0.94 (0.88, 1.01) 0.81 (0.77, 0.86) ..........................................................................................................................................................................................
University of California, San Francisco, San Francisco, California
OBJECTIVE: Given the continuing increasing rate of cesarean delivery, we sought to examine whether number of prior cesarean delivery is associated with increased risk of complications. STUDY DESIGN: This is a retrospective cohort study of term, singleton pregnancies with prior cesarean deliveries (CD) in 2005 in 12 states using the revised birth certificate data. Perinatal outcomes were compared by number of previous CD, categorized as 1, 2, 3, or ⬎⫽4. Statistical comparison was performed using chi-square test and multivariable logistic regression models, with one cesarean delivery as the referent. RESULTS: There were 143,260 women meeting study criteria. The association between number of prior cesarean delivery and neonatal outcomes is summarized (Table).
CONCLUSION: In this population-based cohort, the number of prior ce-
sarean delivery is not associated with increased perinatal morbidity except for admissions to the intensive care nursery in neonates born to women with 4 or more prior cesarean deliveries compared to one prior. 0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.443
579 Risk of short interpregnancy intervals among women in California
Other 0.70 (0.32, 2.50) 1.40 (1.01, 1.95) 1.27 (1.04, 1.54) 1.19 (1.02, 1.39) .......................................................................................................................................................................................... 0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.444
580 How short is too short? The risk of preterm birth with inadequate birth spacing Allison Bryant1, Erin Madden2 1 University of California, San Francisco, Obstetrics, Gynecology and Reproductive Sciences, San Francisco, California, 2University of California, San Francisco, San Francisco, California
OBJECTIVE: To determine the effect of short birth-to-conception in-
tervals on the risk of preterm birth among women of different race/ ethnicities in California. STUDY DESIGN: Birth certificate data from all births in the state from 1999-2004 were linked with hospital discharge data. For women with a first birth in 1999-2000 and a second birth by 2004, multivariable modeling was used to determine risk factors for preterm birth, with a particular interest in the effect of birth-to-conception interval. Tests of interaction were conducted to assess for modification of the effect of birth interval on prematurity by race/ethnicity and by prior preterm birth. RESULTS: Of 190,099 women with a first birth in 1999-2000 and a second birth by 2004, the risk of delivery ⬍37, ⬍32 and ⬍28 weeks in the second birth was 8.4%, 1.0% and 0.3%, respectively. The adjusted odds of prematurity associated with a short birth-to-conception interval and race are presented in the Table. There was no modification by race of the effect of interval on preterm birth risk; however, for women with a prior preterm birth and an interval of ⬍6 months, the odds of a preterm birth ⬍28 weeks was 2.3 [1.2, 4.5] times higher than it would have been for either risk factor alone. AOR of PTB by interval and race
Allison Bryant1, Erin Madden1 1
University of California, San Francisco, San Francisco, California
OBJECTIVE: To determine risk factors for inadequate birth spacing, a risk factor for adverse perinatal outcomes, among women in California. STUDY DESIGN: Data from vital statistics records for all births in the state between 1999 and 2004 were linked with hospital discharge data. For women with a first birth in 1999-2000 and a second birth by 2004, multivariable modeling was used to determine risk factors for short birth-to-conception intervals. RESULTS: Of 370,539 with a first birth in 1999-2000, 190,099 (51.3%) had a second birth by 2004. Of these women, the risk of a birth-toconception interval of ⬍3, ⬍6, ⬍12 and ⬍18 months was 0.9%, 3.3%, 10.9% and 19.9%, respectively. Independent risk factors for very short intervals (⬍6 months) included maternal age ⬍26 years, racial/ethnic minority status (see Table), lower levels of education, residence in an urban county, vaginal delivery of first infant and having had a birth at ⬍32 weeks in the first pregnancy (AOR 1.35 [1.12, 1.63]).
S214
⬍18m v. ⱖ18m
<37w
<32w
<28w
1.05 (1.0, 1.1)
1.26 (1.11, 1.44)
1.28 (1.02, 1.61)
..........................................................................................................................................................................................
⬍12m v. ⱖ12m 1.1 (1.04, 1.17) 1.47 (1.27, 1.69) 1.6 (1.27, 2.1) .......................................................................................................................................................................................... ⬍6m v. ⱖ6m 1.2 (1.1, 1.31) 1.88 (1.55, 2.3) 2.2 (1.62, 3.1) .......................................................................................................................................................................................... ⬍3m v. ⱖ3m 1.07 (0.9, 1.25) 1.73 (1.22, 2.4) 1.88 (1.05, 3.4) .......................................................................................................................................................................................... White 1 1 1 .......................................................................................................................................................................................... Black 1.47 (1.33, 1.63) 1.86 (1.45, 2.4) 1.98 (1.25, 3.1) .......................................................................................................................................................................................... Hisp. 1.1 (1.03, 1.18) 1.15 (0.95, 1.39) 1.5 (1.01, 2.1) .......................................................................................................................................................................................... Asian 1.26 (1.16, 2.38) 1.43 (1.12, 1.83) 2.2 (1.45, 3.3) ..........................................................................................................................................................................................
CONCLUSION: The risk of prematurity is associated with maternal race/
ethnicity, prior preterm birth and short birth intervals; the risks of the latter two are multiplicative. Women with a preterm birth should be well counseled to avoid short interpregnancy intervals. 0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.445
American Journal of Obstetrics & Gynecology Supplement to DECEMBER 2009
Academic Issues, etc
www.AJOG.org CONCLUSION: Short interpregnancy intervals (IPI) are common
among women following their first delivery. Underserved women are at particularly high risk, as are women with a prior early preterm birth (EPTB). Disparities in short IPIs are most pronounced for very short intervals. Interventions to improve birth spacing may affect the risk of future adverse perinatal outcomes. In particular, attention should be directed toward women with prior EPTB, whose risk of subseqent adverse pregnancy outcomes is already higher at baseline. Adjusted odds of short interval by race/ethnicity
CONCLUSION: Compared to Caucasians, African American, Latina/
Hispanic, and Other non-Hispanic women with twins have higher risk of neonatal complications.
< 3 months White 1.00
< 6 months
< 12 months
< 18 months
1.00
1.00
1.00
0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.442
..........................................................................................................................................................................................
578 Number of prior cesarean delivery and perinatal outcomes: more is worse?
Hisp. 1.52 (1.33, 1.74) 1.36 (1.27, 1.46) 1.13 (1.09, 1.18) 1.05 (1.02, 1.09) ..........................................................................................................................................................................................
1
1
Asian 1.84 (1.54, 2.20) 1.80 (1.65, 1.90) 1.28 (1.22, 1.35) 1.06 (1.02, 1.11) .......................................................................................................................................................................................... 1
Yvonne Cheng , Sanae Nakagawa , Aaron Caughey 1
Black 1.44 (1.16, 1.79) 1.17 (1.04, 1.32) 0.94 (0.88, 1.01) 0.81 (0.77, 0.86) ..........................................................................................................................................................................................
University of California, San Francisco, San Francisco, California
OBJECTIVE: Given the continuing increasing rate of cesarean delivery, we sought to examine whether number of prior cesarean delivery is associated with increased risk of complications. STUDY DESIGN: This is a retrospective cohort study of term, singleton pregnancies with prior cesarean deliveries (CD) in 2005 in 12 states using the revised birth certificate data. Perinatal outcomes were compared by number of previous CD, categorized as 1, 2, 3, or ⬎⫽4. Statistical comparison was performed using chi-square test and multivariable logistic regression models, with one cesarean delivery as the referent. RESULTS: There were 143,260 women meeting study criteria. The association between number of prior cesarean delivery and neonatal outcomes is summarized (Table).
CONCLUSION: In this population-based cohort, the number of prior ce-
sarean delivery is not associated with increased perinatal morbidity except for admissions to the intensive care nursery in neonates born to women with 4 or more prior cesarean deliveries compared to one prior. 0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.443
579 Risk of short interpregnancy intervals among women in California
Other 0.70 (0.32, 2.50) 1.40 (1.01, 1.95) 1.27 (1.04, 1.54) 1.19 (1.02, 1.39) .......................................................................................................................................................................................... 0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.444
580 How short is too short? The risk of preterm birth with inadequate birth spacing Allison Bryant1, Erin Madden2 1 University of California, San Francisco, Obstetrics, Gynecology and Reproductive Sciences, San Francisco, California, 2University of California, San Francisco, San Francisco, California
OBJECTIVE: To determine the effect of short birth-to-conception in-
tervals on the risk of preterm birth among women of different race/ ethnicities in California. STUDY DESIGN: Birth certificate data from all births in the state from 1999-2004 were linked with hospital discharge data. For women with a first birth in 1999-2000 and a second birth by 2004, multivariable modeling was used to determine risk factors for preterm birth, with a particular interest in the effect of birth-to-conception interval. Tests of interaction were conducted to assess for modification of the effect of birth interval on prematurity by race/ethnicity and by prior preterm birth. RESULTS: Of 190,099 women with a first birth in 1999-2000 and a second birth by 2004, the risk of delivery ⬍37, ⬍32 and ⬍28 weeks in the second birth was 8.4%, 1.0% and 0.3%, respectively. The adjusted odds of prematurity associated with a short birth-to-conception interval and race are presented in the Table. There was no modification by race of the effect of interval on preterm birth risk; however, for women with a prior preterm birth and an interval of ⬍6 months, the odds of a preterm birth ⬍28 weeks was 2.3 [1.2, 4.5] times higher than it would have been for either risk factor alone. AOR of PTB by interval and race
Allison Bryant1, Erin Madden1 1
University of California, San Francisco, San Francisco, California
OBJECTIVE: To determine risk factors for inadequate birth spacing, a risk factor for adverse perinatal outcomes, among women in California. STUDY DESIGN: Data from vital statistics records for all births in the state between 1999 and 2004 were linked with hospital discharge data. For women with a first birth in 1999-2000 and a second birth by 2004, multivariable modeling was used to determine risk factors for short birth-to-conception intervals. RESULTS: Of 370,539 with a first birth in 1999-2000, 190,099 (51.3%) had a second birth by 2004. Of these women, the risk of a birth-toconception interval of ⬍3, ⬍6, ⬍12 and ⬍18 months was 0.9%, 3.3%, 10.9% and 19.9%, respectively. Independent risk factors for very short intervals (⬍6 months) included maternal age ⬍26 years, racial/ethnic minority status (see Table), lower levels of education, residence in an urban county, vaginal delivery of first infant and having had a birth at ⬍32 weeks in the first pregnancy (AOR 1.35 [1.12, 1.63]).
S214
⬍18m v. ⱖ18m
<37w
<32w
<28w
1.05 (1.0, 1.1)
1.26 (1.11, 1.44)
1.28 (1.02, 1.61)
..........................................................................................................................................................................................
⬍12m v. ⱖ12m 1.1 (1.04, 1.17) 1.47 (1.27, 1.69) 1.6 (1.27, 2.1) .......................................................................................................................................................................................... ⬍6m v. ⱖ6m 1.2 (1.1, 1.31) 1.88 (1.55, 2.3) 2.2 (1.62, 3.1) .......................................................................................................................................................................................... ⬍3m v. ⱖ3m 1.07 (0.9, 1.25) 1.73 (1.22, 2.4) 1.88 (1.05, 3.4) .......................................................................................................................................................................................... White 1 1 1 .......................................................................................................................................................................................... Black 1.47 (1.33, 1.63) 1.86 (1.45, 2.4) 1.98 (1.25, 3.1) .......................................................................................................................................................................................... Hisp. 1.1 (1.03, 1.18) 1.15 (0.95, 1.39) 1.5 (1.01, 2.1) .......................................................................................................................................................................................... Asian 1.26 (1.16, 2.38) 1.43 (1.12, 1.83) 2.2 (1.45, 3.3) ..........................................................................................................................................................................................
CONCLUSION: The risk of prematurity is associated with maternal race/
ethnicity, prior preterm birth and short birth intervals; the risks of the latter two are multiplicative. Women with a preterm birth should be well counseled to avoid short interpregnancy intervals. 0002-9378/$ – see front matter • doi:10.1016/j.ajog.2009.10.445
American Journal of Obstetrics & Gynecology Supplement to DECEMBER 2009