title: Twin pregnancies after assisted reproductive technologies: the role of maternal age on pregnancy outcome.
abstract: OBJECTIVE
  Our aim was to investigate whether advanced maternal age (≥40years) still impairs the outcome of twin pregnancies after assisted reproductive techniques (ART).
  
  
  METHODS
  The retrospective observational study evaluated 430 nulliparous dichorionic diamniotic twin pregnancies conceived with ART. The population was divided into women <40 years old (Group A, n=265) and ≥40 years old (Group B, n=165).
  
  
  RESULTS
  Gestational diabetes mellitus and gestational hypertension/preeclampsia were significantly more frequent in nulliparous twin pregnancies after ART ≥40years compared to <40years (p=0.021 and p<0.001, respectively). In univariate analysis of twin pregnancies after ART, there was only a trend of higher incidence of total preterm birth (PB) rate within mother aged ≥40 years old (p=0.104). However, Group A showed higher rate of spontaneous preterm birth (SPB) <37 weeks, whereas Group B showed significantly higher rate of iatrogenic PB <37 weeks of gestation (p=0.023 and p=0.001, respectively). For delivery <32 weeks of gestation, the rate of SPB in Group A was significantly higher (p=0.002). A higher incidence of PB was observed in Group B after heterologous treatment (p<0.001). Despite this, the absolute prevalence of PB in the entire population is higher in Group A, both after autologous (22.5%) and heterologous (25%) ART treatment, than in Group B (10.1% vs 21.4%).
  
  
  CONCLUSIONS
  Our data indicate that nulliparous twin pregnancies conceived with ART in mothers ≥40 years old did not show significantly higher incidence of PB, even if an increased rate of iatrogenic PB <37 weeks is showed.
authors.affiliation: Obstetrics and Gynecology, Department of Health Sciences, University of Florence, Florence, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Pinzauti
authors.affiliation: Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Ferrata
authors.affiliation: Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Vannuccini
authors.affiliation: Obstetrics and Gynecology, Department of Health Sciences, University of Florence, Florence, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Di Rienzo
authors.affiliation: Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.
authors.forename: Filiberto M
authors.initials: FM
authors.lastname: Severi
authors.affiliation: Obstetrics and Gynecology, Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy. Electronic address: felice.petraglia@unisi.it.
authors.forename: Felice
authors.initials: F
authors.lastname: Petraglia
authors.affiliation: Obstetrics and Gynecology, Department of Health Sciences, University of Florence, Florence, Italy.
authors.forename: Mariarosaria
authors.initials: M
authors.lastname: Di Tommaso
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D008423:Maternal Age; D011247:Pregnancy; D011256:Pregnancy Outcome; D059285:Pregnancy, Twin; D047928:Premature Birth / Q000453:epidemiology*; D027724:Reproductive Techniques, Assisted; D012189:Retrospective Studies
keywords: Assisted reproductive technologies; Maternal age; Pregnancy outcome; Preterm birth; Twins