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The contribution of assisted conception, chorionicity and other risk factors to very low birthweight in a twin cohort
Author(s) -
Lynch Anne,
McDuffie Robert,
Stephens Janet,
Murphy James,
Faber Kenneth,
Orleans Miriam
Publication year - 2003
Publication title -
bjog: an international journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.157
H-Index - 164
eISSN - 1471-0528
pISSN - 1470-0328
DOI - 10.1046/j.1471-0528.2003.02342.x
Subject(s) - medicine , obstetrics , odds ratio , miscarriage , gestation , cohort , pregnancy , gestational age , low birth weight , retrospective cohort study , cohort study , logistic regression , premature birth , gynecology , genetics , biology
Objectives To investigate the contribution of assisted conception (assisted reproductive technology and ovulation induction), chorionicity and selected maternal risk factors for very low birthweight. Design Retrospective twin cohort study. Setting Staff model Colorado Health Maintenance Organization. Sample Five hundred and sixty‐two twin gestations [assisted = 193 (34%); unassisted = 369 (66%)]. Methods Data were collected from a perinatal database and medical record review. Data were analysed using univariate and multivariable logistic regression analysis. Main outcome measure Very low birthweight. Results Women with assisted twin gestation were more likely to be older, nulliparous, non‐smokers, married, have a prior history of a miscarriage and a dichorionic placentation. There was no difference in the distribution of low and very low birthweight, discordant growth or preterm delivery between assisted and unassisted twin gestations. Significant risk factors for very low birthweight were: a prior preterm birth (odds ratio, OR, 3.8, 95% confidence interval, CI, 2, 7), monochorionicity (OR 3, 95% CI 2, 4.7), nulliparity (OR 2, 95% CI 1.3, 3), cigarette smoking (OR 1.8, 95% CI 1, 3) and prior miscarriage (OR 1.6, 95% CI 1, 2). Monochorionicity was significantly associated with adverse perinatal outcomes. Conclusion Assisted conception did not play a significant role in the occurrence of very low birthweight in this cohort. A history of preterm birth and a monochorionic twin gestation were the leading risk factors for very low birthweight. Associated risk factors for very low birthweight were nulliparity, cigarette smoking and a prior miscarriage.