Objective
To quantify the effect of medical and obstetrical factors on the odds of cesarean
delivery, comparing assisted reproductive technology (ART)–treated women and women
with subfertility not treated with ART versus fertile women.
Design
Retrospective cohort.
Setting
Not applicable.
Patient(s)
Singleton deliveries to primiparous women; with the source of this data being the
Massachusetts vital and hospital records linked to the Society for Assisted Reproductive
Technology Clinic Outcome Reporting System data (2004-2010).
Intervention(s)
None.
Main Outcome Measure(s)
Mode of delivery.
Result(s)
The 173,130 deliveries included 5,768 ART-treated, 2,657 subfertile (1,627 non-ART
medically assisted reproduction [MAR] and 1,030 unassisted infertile), and 164,705
fertile pregnancies and 117,743 vaginal and 55,387 cesarean deliveries. ART-treated
women were older, more often white and non-Hispanic, and with more private insurance,
previous uterine surgery, gestational diabetes, pregnancy hypertension, bleeding,
and placental complications than fertile women. Overall rates of cesarean delivery
were 45.7%, 43.3%, and 31.1% for ART-treated, subfertile, and fertile women and 41.7%
and 45.9% for MAR and unassisted infertile deliveries. When adjusted for demographics,
underlying medical factors, previous uterine surgery, and placental and delivery complications,
adjusted odds ratios (ORs) compared with fertile women were 1.27 for ART-treated and
1.15 for subfertile women, with greater odds among unassisted infertile (OR 1.26)
but not MAR (OR 1.09) women. The strongest confounders of odds of cesarean delivery
were age and previous uterine surgery.
Conclusion(s)
ART and unassisted infertility were associated with greater odds of cesarean compared
with fertile women. Underlying medical and obstetrical risks had strong confounding
effects strongly attenuating the odds for cesarean delivery.
Factores asociados al incremento de las tasas de parto por cesárea en las gestaciones
secundarias a TRA
Objetivo
Cuantificar el efecto de los factores médicos y obstétricos en la tasa de partos por
cesárea, comparando las mujeres con TRA y mujeres con subfertilidad y no tratadas
en TRA versus mujeres fértiles.
Diseño
Estudio de cohorte retrospectivo.
Ajustes
No aplican.
Pacientes
Partos con feto único en mujeres primíparas.
Intervención
Ninguna.
Medida principal
Modalidad de parto.
Resultados
Los 173.130 partos, han incluido 5.768 gestaciones secundarias a TRA, 2.657 gestaciones
en mujeres subfértiles (1.627 gestaciones medicamente asistidas no-TRA y 1.030 gestaciones
naturales en mujeres infértiles) y 164.705 gestaciones en mujeres fértiles y 117.743
partos vaginales y 55.387 partos por cesárea. Las mujeres con gestaciones secundarias
a TRA, la mayoría blancas no-hispanas, con seguros privados, han tenido una edad mayor,
y un mayor número de cirugías uterinas previas, más diabetes gestacional, HTA asociada
a la gestación, sangrados y complicaciones placentarias comparando con las mujeres
fértiles. La tasa media de partos por cesárea ha sido 45,7%, 43,3% y 31,1% para las
gestaciones por TRA, subfértiles, y mujeres fértiles y 41,7% y 45,9% para las gestaciones
medicamente asistidas no-TRA y gestaciones naturales en mujeres infértiles. Cuando
se ha ajustado por demografía, factores médicos coexistentes, cirugías uterinas previas,
y complicaciones placentarias y en el momento del parto, el ratio (ORs) ajustado comparado
con las mujeres fértiles ha sido de 1,27 para las gestaciones secundarias a TRA y
1,15 para las mujeres infértiles con mayor ratio dentro del grupo de gestaciones naturales
en mujeres infértiles (OR 1,26) pero no en el grupo de gestaciones medicamente asistidas
no-TRA (OR 1,09). El mayor impacto sobre el ratio de los partos por cesárea está relacionado
con la edad y las cirugías uterinas previas.
Conclusiones
TRA y la infertilidad no asistida medicamente han sido asociadas a mayores tasas de
parto por cesárea comparando con las mujeres fértiles. Los factores de riesgo médicos
y obstétricos subyacentes han sido un efecto importante de confusión atenuando fuertemente
las tasas de parto por cesárea.
Key Words
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Article Info
Publication History
Accepted:
April 24,
2018
Received in revised form:
March 27,
2018
Received:
December 5,
2017
Footnotes
J.E.S. has nothing to disclose. C.L. has nothing to disclose. H.J.C. has nothing to disclose. E.G.R. has nothing to disclose. C.C.C. has nothing to disclose. S.A.M. has nothing to disclose. H.D. has nothing to disclose.
Supported by National Institutes of Health grant RO1HD067270.
Presented as an abstract at the American Society for Reproductive Medicine Annual meeting, October 29–November 1, 2017.
Identification
Copyright
©2018 American Society for Reproductive Medicine, Published by Elsevier Inc.
