Dizygotic twin pregnancies after medically assisted reproduction and after natural conception: maternal and perinatal outcomes

Abstract

Objective: To compare maternal and perinatal outcomes in dizygotic twin pregnancies conceived after medically assisted reproduction (MAR) with outcomes after natural conception (NC).

Design: Nationwide registry based study.

Setting: Academic medical center.

Patient(s): Primiparous women who delivered opposite sex twins between January 2000 and December 2012 in the Netherlands, comprising dizygotic twin pregnancies: 6,694 women, 470 after ovulation induction (OI), 511 after intrauterine insemination with controlled ovarian hyperstimulation (IUI-COH), 2,437 after in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI), and 3,276 after NC.

Intervention(s): None.

Main outcome measure(s): Multivariable logistic regression and generalized linear mixed models to evaluate differences in outcomes: maternal outcomes of hypertension, preeclampsia, preterm delivery, hemorrhage, and delivery mode, perinatal outcomes including small for gestational age (SGA) with birth weight <10th percentile, birth weight <1,500 g, 5-minute Apgar score <7, admission to neonatal intensive care unit, congenital anomalies, and perinatal mortality.

Result(s): We found no statistically significant differences in maternal or perinatal outcomes after OI compared with NC. Women pregnant after IVF-ICSI had a lower risk for hypertension (adjusted odds ratio [aOR] 0.74; 95% confidence interval [CI], 0.66-0.83) compared with women pregnant after NC. After IUI-COH more children had Apgar scores <7 (adjusted odds ratio (aOR) 1.38; 95% confidence interval (CI) 1.05-1.81) and perinatal mortality rates were higher (aOR 1.56; 95% CI, 1.04-2.33) compared with NC. We found no differences in perinatal outcomes after IVF-ICSI compared with NC.

Conclusion(s): Overall, maternal and perinatal risks other than those due to multiplicity are similar for twin pregnancies conceived after MAR and after NC.

Keywords: Intrauterine insemination; in vitro fertilization; natural conception; ovulation induction; twin pregnancy.