Accepted Manuscript Risk factors for cesarean delivery in twin pregnancies attempting vaginal delivery Nathan S. Fox, MD Simi Gupta, MD Stephanie Melka, MD Michael Silverstein, MD Samuel Bender, MD Daniel H. Saltzman, MD Chad K. Klauser, MD Andrei Rebarber, MD PII:
S0002-9378(14)00805-9
DOI:
10.1016/j.ajog.2014.07.056
Reference:
YMOB 9979
To appear in:
American Journal of Obstetrics and Gynecology
Received Date: 28 April 2014 Revised Date:
15 June 2014
Accepted Date: 30 July 2014
Please cite this article as: Fox NS, Gupta S, Melka S, Silverstein M, Bender S, Saltzman DH, Klauser CK, Rebarber A, Risk factors for cesarean delivery in twin pregnancies attempting vaginal delivery, American Journal of Obstetrics and Gynecology (2014), doi: 10.1016/j.ajog.2014.07.056. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Fox et al
Risk factors for cesarean delivery in twin pregnancies attempting vaginal delivery Nathan S. FOX, MD, Simi GUPTA, MD, Stephanie MELKA, MD, Michael SILVERSTEIN, MD, Samuel BENDER, MD, Daniel H. SALTZMAN, MD, Chad K. KLAUSER, MD, and Andrei REBARBER, MD
Word Count Abstract – 209 Manuscript – 2417
33
EP
Running Foot – Risk factors for cesarean delivery in twins
AC C
32
SC
Key Words – Twins; labor; cesarean delivery; advanced maternal age, nulliparity
30 31
M AN U
Corresponding Author Nathan S. Fox, MD Maternal Fetal Medicine Associates, PLLC 70 East 90th Street New York, NY 10128 Phone: 212-722-7409 Fax: 212-722-7185 [email protected]
RI PT
From Maternal Fetal Medicine Associates, PLLC, and the Department of Obstetrics, Gynecology, and Reproductive Science, Icahn School of Medicine at Mount Sinai
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
1
Disclosure:
The authors report no conflicts of interest
ACCEPTED MANUSCRIPT Fox et al
2
1
Precis
2
In patients with twin pregnancies attempting vaginal delivery, nulliparity and advanced
3
maternal age are independently associated with cesarean delivery in labor.
AC C
EP
TE D
M AN U
SC
RI PT
4
ACCEPTED MANUSCRIPT Fox et al
3
1
Abstract
2
Objective:
3
twin pregnancies attempting vaginal delivery.
4
Methods:
5
June 2005 and February 2014. Baseline characteristics were compared between women
6
who delivered vaginally and women who underwent cesarean delivery in labor. Logistic
7
regression analysis was performed to estimate independent risk factors for cesarean
8
delivery.
9
Results:
To estimate independent risk factors for cesarean delivery in patients with
SC
RI PT
Historical cohort of twin pregnancies delivered in one practice between
M AN U
286 women with twin pregnancies attempting vaginal delivery were
included in the study. The overall modes of delivery were: vaginal delivery 82.2%,
11
cesarean delivery 17.8%, and combined vaginal-cesarean delivery 0%. The most
12
common indication for cesarean delivery in labor was an arrest disorder (82.4%). The
13
risk factors independently associated with cesarean delivery were nulliparity (aOR 5.78,
14
95% CI 2.24, 14.88) and advanced maternal age ≥35 years (aOR 2.36, 95% CI 1.16,
15
4.80). The patients at highest risk for cesarean delivery (nulliparous, AMA, induced
16
labor) still had a 48.6% likelihood of vaginal delivery.
17
Conclusions: In patients with twin pregnancies attempting labor, nulliparity and
18
advanced maternal age are independently associated with cesarean delivery in labor.
19
However, even the patients at highest risk for cesarean delivery have nearly a 50%
20
likelihood of successful vaginal delivery and therefore should be allowed to attempt
21
vaginal delivery if desired and not otherwise contraindicated.
22 23
AC C
EP
TE D
10
ACCEPTED MANUSCRIPT Fox et al
4
Background
2
Twins now represent 3.3% of all US live births [1]. The majority of twins are born via
3
cesarean delivery, and this rate has been increasing. In the US, the rate of cesarean
4
delivery of women with twin pregnancies rose from 53% in 1995 to 75% in 2008 [2].
5
This increase was seen both in vertex and breech twins, and after adjustment for several
6
risk factors, there was an approximate increase in cesarean delivery rate of 5% per year
7
[2].
SC
RI PT
1
8
The safety of vaginal delivery of twins was suggested by several large observational
M AN U
9
studies [3-5] and was recently established in a large, prospective, randomized trial [6]. In
11
that trial of 1398 women (2795 fetuses), the overall outcome of fetal or neonatal death or
12
serious neonatal morbidity did not differ between women in the planned-cesarean-
13
delivery group and women in the planned-vaginal-delivery group. Based primarily on
14
the results of this study, a recent consensus statement by the American College of
15
Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine
16
(SMFM), stated that women with twin pregnancies and a cephalic presenting twin should
17
be counseled to attempt vaginal delivery and that it is important to train residents to
18
perform vaginal delivery of twins [7,8].
EP
AC C
19
TE D
10
20
However, when counseling women with twin pregnancies about mode of delivery, it is
21
important to discuss not only the safety of vaginal delivery, but also the likelihood of a
22
successful vaginal delivery for those who attempt it. In a recent large series of twins in
23
Ireland, a trial of labor was attempted in 441 twin pregnancies and was successful in 338
ACCEPTED MANUSCRIPT Fox et al
5
(77%) [9]. In that series, vaginal breech extraction of the second twin was performed in
2
29% of those who delivered vaginally, and 4% of patients had a combined vaginal-
3
cesarean delivery. On univariate analysis, they found that the risk factors for cesarean
4
delivery in labor were nulliparity and assisted conception. However, this analysis did not
5
control for other variables. We published our own experience of twin deliveries using
6
active management of the second stage [5]. Among 130 women who attempted vaginal
7
delivery, 84.6% were successful, vaginal breech extraction of the second twin was
8
performed in 77% of those who delivered vaginally, and there were no combined vaginal-
9
cesarean deliveries. We found on univariate analysis that older maternal age and
M AN U
SC
RI PT
1
nulliparity were associated with cesarean delivery [5]. Since there are many confounding
11
risk factors in twin pregnancies (for example maternal age and assisted reproduction, or
12
maternal weight and gestational diabetes), it is important when analyzing risk factors for
13
cesarean delivery that the statistical methods used are able to control for these
14
confounders and estimate independent risk factors for cesarean delivery.
TE D
10
15
The objective of this study was to use regression analysis to estimate independent risk
17
factors for cesarean delivery in a large single-center cohort of women in the US with twin
18
pregnancies attempting vaginal delivery. Using this data, obstetricians and patients with
19
twin pregnancies could better understand the risk of cesarean delivery in labor and make
20
an informed decision about mode of delivery.
AC C
EP
16
ACCEPTED MANUSCRIPT Fox et al
6
Methods
2
After Biomedical Research Alliance of New York Institutional Review Board approval
3
was obtained, the charts of all patients with twin pregnancies ≥24 weeks delivered by a
4
single maternal-fetal medicine practice between June 2005 (when our electronic medical
5
record was established) and February 2014 were reviewed. We excluded patients who did
6
not attempt vaginal delivery, as well as patients for whom one or both of the twins were
7
not alive in labor. Baseline characteristics and pregnancy outcomes were obtained from
8
our computerized medical record. This analysis includes data from 130 patients in our
9
original report of twin deliveries who attempted labor [5], as well as all of our patients
SC
M AN U
10
RI PT
1
with twin pregnancies who attempted labor subsequent to that publication.
11
All patients were delivered in a tertiary-care academic medical center with a level III
13
neonatal intensive care nursery and 24-hour in-house pediatric and obstetrical anesthesia
14
availability. All patients’ labors were managed and deliveries performed by one of the
15
attending obstetricians in our practice, with house staff involvement in all cases. Our
16
protocols for management of labor [5] as well as induction of labor [10] in twin
17
pregnancies have been described previously. In short, contraindications to vaginal twin
18
delivery of twins in our practice are nonvertex presenting twin, nonvertex second twin
19
with an estimated fetal weight >20% larger than the presenting twin, nonvertex second
20
twin with an estimated fetal weight
S0002-9378(14)00805-9
DOI:
10.1016/j.ajog.2014.07.056
Reference:
YMOB 9979
To appear in:
American Journal of Obstetrics and Gynecology
Received Date: 28 April 2014 Revised Date:
15 June 2014
Accepted Date: 30 July 2014
Please cite this article as: Fox NS, Gupta S, Melka S, Silverstein M, Bender S, Saltzman DH, Klauser CK, Rebarber A, Risk factors for cesarean delivery in twin pregnancies attempting vaginal delivery, American Journal of Obstetrics and Gynecology (2014), doi: 10.1016/j.ajog.2014.07.056. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Fox et al
Risk factors for cesarean delivery in twin pregnancies attempting vaginal delivery Nathan S. FOX, MD, Simi GUPTA, MD, Stephanie MELKA, MD, Michael SILVERSTEIN, MD, Samuel BENDER, MD, Daniel H. SALTZMAN, MD, Chad K. KLAUSER, MD, and Andrei REBARBER, MD
Word Count Abstract – 209 Manuscript – 2417
33
EP
Running Foot – Risk factors for cesarean delivery in twins
AC C
32
SC
Key Words – Twins; labor; cesarean delivery; advanced maternal age, nulliparity
30 31
M AN U
Corresponding Author Nathan S. Fox, MD Maternal Fetal Medicine Associates, PLLC 70 East 90th Street New York, NY 10128 Phone: 212-722-7409 Fax: 212-722-7185 [email protected]
RI PT
From Maternal Fetal Medicine Associates, PLLC, and the Department of Obstetrics, Gynecology, and Reproductive Science, Icahn School of Medicine at Mount Sinai
TE D
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
1
Disclosure:
The authors report no conflicts of interest
ACCEPTED MANUSCRIPT Fox et al
2
1
Precis
2
In patients with twin pregnancies attempting vaginal delivery, nulliparity and advanced
3
maternal age are independently associated with cesarean delivery in labor.
AC C
EP
TE D
M AN U
SC
RI PT
4
ACCEPTED MANUSCRIPT Fox et al
3
1
Abstract
2
Objective:
3
twin pregnancies attempting vaginal delivery.
4
Methods:
5
June 2005 and February 2014. Baseline characteristics were compared between women
6
who delivered vaginally and women who underwent cesarean delivery in labor. Logistic
7
regression analysis was performed to estimate independent risk factors for cesarean
8
delivery.
9
Results:
To estimate independent risk factors for cesarean delivery in patients with
SC
RI PT
Historical cohort of twin pregnancies delivered in one practice between
M AN U
286 women with twin pregnancies attempting vaginal delivery were
included in the study. The overall modes of delivery were: vaginal delivery 82.2%,
11
cesarean delivery 17.8%, and combined vaginal-cesarean delivery 0%. The most
12
common indication for cesarean delivery in labor was an arrest disorder (82.4%). The
13
risk factors independently associated with cesarean delivery were nulliparity (aOR 5.78,
14
95% CI 2.24, 14.88) and advanced maternal age ≥35 years (aOR 2.36, 95% CI 1.16,
15
4.80). The patients at highest risk for cesarean delivery (nulliparous, AMA, induced
16
labor) still had a 48.6% likelihood of vaginal delivery.
17
Conclusions: In patients with twin pregnancies attempting labor, nulliparity and
18
advanced maternal age are independently associated with cesarean delivery in labor.
19
However, even the patients at highest risk for cesarean delivery have nearly a 50%
20
likelihood of successful vaginal delivery and therefore should be allowed to attempt
21
vaginal delivery if desired and not otherwise contraindicated.
22 23
AC C
EP
TE D
10
ACCEPTED MANUSCRIPT Fox et al
4
Background
2
Twins now represent 3.3% of all US live births [1]. The majority of twins are born via
3
cesarean delivery, and this rate has been increasing. In the US, the rate of cesarean
4
delivery of women with twin pregnancies rose from 53% in 1995 to 75% in 2008 [2].
5
This increase was seen both in vertex and breech twins, and after adjustment for several
6
risk factors, there was an approximate increase in cesarean delivery rate of 5% per year
7
[2].
SC
RI PT
1
8
The safety of vaginal delivery of twins was suggested by several large observational
M AN U
9
studies [3-5] and was recently established in a large, prospective, randomized trial [6]. In
11
that trial of 1398 women (2795 fetuses), the overall outcome of fetal or neonatal death or
12
serious neonatal morbidity did not differ between women in the planned-cesarean-
13
delivery group and women in the planned-vaginal-delivery group. Based primarily on
14
the results of this study, a recent consensus statement by the American College of
15
Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine
16
(SMFM), stated that women with twin pregnancies and a cephalic presenting twin should
17
be counseled to attempt vaginal delivery and that it is important to train residents to
18
perform vaginal delivery of twins [7,8].
EP
AC C
19
TE D
10
20
However, when counseling women with twin pregnancies about mode of delivery, it is
21
important to discuss not only the safety of vaginal delivery, but also the likelihood of a
22
successful vaginal delivery for those who attempt it. In a recent large series of twins in
23
Ireland, a trial of labor was attempted in 441 twin pregnancies and was successful in 338
ACCEPTED MANUSCRIPT Fox et al
5
(77%) [9]. In that series, vaginal breech extraction of the second twin was performed in
2
29% of those who delivered vaginally, and 4% of patients had a combined vaginal-
3
cesarean delivery. On univariate analysis, they found that the risk factors for cesarean
4
delivery in labor were nulliparity and assisted conception. However, this analysis did not
5
control for other variables. We published our own experience of twin deliveries using
6
active management of the second stage [5]. Among 130 women who attempted vaginal
7
delivery, 84.6% were successful, vaginal breech extraction of the second twin was
8
performed in 77% of those who delivered vaginally, and there were no combined vaginal-
9
cesarean deliveries. We found on univariate analysis that older maternal age and
M AN U
SC
RI PT
1
nulliparity were associated with cesarean delivery [5]. Since there are many confounding
11
risk factors in twin pregnancies (for example maternal age and assisted reproduction, or
12
maternal weight and gestational diabetes), it is important when analyzing risk factors for
13
cesarean delivery that the statistical methods used are able to control for these
14
confounders and estimate independent risk factors for cesarean delivery.
TE D
10
15
The objective of this study was to use regression analysis to estimate independent risk
17
factors for cesarean delivery in a large single-center cohort of women in the US with twin
18
pregnancies attempting vaginal delivery. Using this data, obstetricians and patients with
19
twin pregnancies could better understand the risk of cesarean delivery in labor and make
20
an informed decision about mode of delivery.
AC C
EP
16
ACCEPTED MANUSCRIPT Fox et al
6
Methods
2
After Biomedical Research Alliance of New York Institutional Review Board approval
3
was obtained, the charts of all patients with twin pregnancies ≥24 weeks delivered by a
4
single maternal-fetal medicine practice between June 2005 (when our electronic medical
5
record was established) and February 2014 were reviewed. We excluded patients who did
6
not attempt vaginal delivery, as well as patients for whom one or both of the twins were
7
not alive in labor. Baseline characteristics and pregnancy outcomes were obtained from
8
our computerized medical record. This analysis includes data from 130 patients in our
9
original report of twin deliveries who attempted labor [5], as well as all of our patients
SC
M AN U
10
RI PT
1
with twin pregnancies who attempted labor subsequent to that publication.
11
All patients were delivered in a tertiary-care academic medical center with a level III
13
neonatal intensive care nursery and 24-hour in-house pediatric and obstetrical anesthesia
14
availability. All patients’ labors were managed and deliveries performed by one of the
15
attending obstetricians in our practice, with house staff involvement in all cases. Our
16
protocols for management of labor [5] as well as induction of labor [10] in twin
17
pregnancies have been described previously. In short, contraindications to vaginal twin
18
delivery of twins in our practice are nonvertex presenting twin, nonvertex second twin
19
with an estimated fetal weight >20% larger than the presenting twin, nonvertex second
20
twin with an estimated fetal weight
