Obstetrical and perinatal complications of twin pregnancies: is there a link with the type of infertility treatment? SOPHIE DELTOMBE-BODART1 , PHILIPPE DERUELLE1,2 , ELODIE DRUMEZ3 SOPHIE CATTEAU-JONARD4 & CHARLES GARABEDIAN1,2 1Department of Obstetrics, GemJDF Project, CHU Lille, Lille, 2EA 4489 – Perinatal Health and Environment, University of Lille, Lille, 3Department of Biostatistics, EA 2694 – Public Health: Epidemiology and Healthcare Quality, CHU Lille, Lille, and 4Department of Reproductive Medicine, CHU Lille, Lille, France ACTA Obstetricia et Gynecologica Scandinavica Journal Club -Obstetrics- July 2017 Edited by Francesco D’Antonio

Background Twin pregnancies are at higher risk of perinatal mortality and morbidity compared to singletons. In singletons pregnancies conceived via assisted reproductive techniques, perinatal outcome has been reported to be less favorable compared to those conceived spontaneously, irrespective of the type of infertility treatment. Findings from multiple gestations are contrasting with several studies reporting higher rates of adverse perinatal outcome in twins conceived via assisted reproductive techniques while others showed no difference.

Aim of the study To compare maternal and perinatal outcome in spontaneous twin pregnancies (SP) with those conceived via assisted reproductive technology (IT).

Methodology Study design: Retrospective single-center cohort study including all twin births between 1997 and 2014 from spontaneous and infertility treatment pregnancies. Exclusion criteria: Twin pregnancies following egg donation. Cases affected by intrauterine fetal death, twin-to-twin transfusion syndrome and fetal anomalies. Outcomes observed: Maternal: Pregnancy-induced hypertension (blood pressure above 140/90 mmHg), preeclampsia (hypertension and proteinuria of 0.3 g/24 h), gestational diabetes, premature rupture of membranes, cholestasis of pregnancy, and placenta previa. Delivery: Route of delivery, incidence of postpartum hemorrhage (defined as >500 mL blood loss), and the presence of perineal tearing. Neonatal: Gestational age at birth, small–for-gestational-age as defined by an estimated fetal weight below the third percentile, low birthweight (<1500 g), birthweight <2500 g, Apgar score <7 at 5 min, admission to the neonatal intensive care unit, neonatal respiratory distress, neonatal sepsis, and neonatal death.

Methodology Statistical analysis: Maternal characteristics were compared between the groups using the chi-squared test for the categorical variables and the Student’s t test for the quantitative variables. Pregnancy, childbirth, and neonatal complications were compared between usinglogistic regression models to adjust for any potential confounders selected a priori [age, gender, chorionicity, and mother’s body mass index (BMI)]. The delivery term (analyzed as a continuous variable) was compared between the groups using an analysis of covariance adjusted for the potential confounders.

Results (1) 1580 twin pregnancies included in the study. 575 received infertility treatment. 152 (26.4%) underwent ovulation induction. 63 (11%) underwent intra-uterine insemination. 192 (33.4%) underwent in vitro fertilization (IVF). 168 (29.2%) underwent intracytoplasmic sperm injection (ICSI).

Results (2) The IT group population was older compared with the SP group. The proportion of primiparous patients was higher in the IT group. There were more dichorionic diamniotic pregnancies in the IT group than the SP group. BMI was significantly different between the two groups.

Results (3) There was no significant difference between the IT and SP groups in any of the observed maternal outcome, or between the types of treatment in the IT group and the SP group.

Results (4) No difference was found between the IT and SP groups in the delivery term or the occurrence of postpartum hemorrhage. No difference was noted between the IT and SP groups in the rate of cesarean sections. No difference was found in the delivery route between the types of treatment in the IT group and the SP group.

Results (4) No significant differences between the IT and SP groups were found regarding the occurrences of small-for-gestational-age, birthweights <1500 g and <2500 g, an Apgar score <7 at 5 min, umbilical cord pH < 7.10, neonatal complications, or neonatal death. No differences were found in the comparisons between the different treatment types in the IT group and the SP group.

Limitations Retrospective design. Single center study. Cases affected by IUD excluded. The study covers a relatively long period of time, with consequent changes in the ART procedures and obstetric practices. No data on the type of IVF pregnancies (fresh or frozen embryos)

Conclusion Twin pregnancies conceived via assisted reproductive technology were not at an increased risk of obstetric and neonatal complications. Furthermore, the type of treatment does not alter the obstetric and neonatal complications.