Effects of parity on preterm delivery in twin gestations conceived with in vitro fertilization
Michael S. Awadalla, M.D.,
Wael H. Salem, M.D.,
Jacqueline R. Ho, M.D.,
Victoria K. Cortessis, Ph.D.,
Ali Ahmady, Ph.D.,
Richard J. Paulson, M.D., M.S.
Affiliations
Michael S. Awadalla, M.D.
Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, California; Reprint requests: Michael S. Awadalla, M.D, Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California Medical Center, 2020 Zonal Avenue, IRD Room 533, Los Angeles, California 90033.
Wael H. Salem, M.D.
Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, California
Jacqueline R. Ho, M.D.
Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, California
Victoria K. Cortessis, Ph.D.
Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, California; Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, California
Ali Ahmady, Ph.D.
Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, California
Richard J. Paulson, M.D., M.S.
Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Keck School of Medicine, University of Southern California, Los Angeles, California
Objective: To determine the relationship between prior obstetrical history and gestational age at delivery in a twin pregnancy. Design: Retrospective cohort study using the United States Society for Assisted Reproductive Technology Clinic Outcomes Reporting System database. Setting: Clinic-based data. Patient(s): Patients undergoing in vitro fertilization (IVF) in the United States with live delivery of twins. Intervention(s): None. Main outcome measure(s): The main outcome measures are median gestational age at delivery and rate of preterm delivery (before 37 weeks). Result(s): The median gestational age at delivery of IVF-conceived twins was 36.3 (interquartile rate 34.4, 37.6) weeks for nulliparous women, 35.9 (34.0, 37.1) weeks for parous women with a prior preterm birth, and 36.7 (35.1, 37.7) weeks for parous women without a prior preterm birth. The rate of preterm delivery was 61% for nulliparous women, 70% for parous women with a prior preterm birth, and 55% for parous women without a prior preterm birth. Conclusion(s): Parous women without a history of preterm delivery had lower rates of preterm delivery in a subsequent twin pregnancy than nulliparous women. Nulliparous women had lower rates of preterm delivery compared with parous women with a history of preterm delivery.
