Secular trends in gestational age and birthweight in twins.
Hum Reprod
; 25(9): 2346-53, 2010 Sep.
Article
em En
| MEDLINE
| ID: mdl-20601680
ABSTRACT
BACKGROUND:
In recent decades, the overall rate of preterm births has increased. The aim of the present study was to examine whether this trend is also seen for multiple gestations. More specifically, we examined if there has been a decrease in gestational age for live born monozygotic (MZ) and dizygotic (DZ) twins and if there has been a simultaneous change in birthweight. The contributions of fertility treatments and Caesarean sections were taken into consideration. All analyses were carried out in two large European twin cohorts.METHODS:
Cross-sectional study of 6310 live born twin pairs, born between 1964-2007, from the Belgian East Flanders Prospective Twin Survey and 14,712 twin pairs, born between 1990-2006, from the Netherlands Twin Register. Multiple regression analyses were performed with gestational age as outcome variable, and multilevel analysis with birthweight as outcome variable. All analyses were performed with and without adjustment for zygosity, parity, maternal age, mode of conception and delivery and, for the analyses of birthweight, gestational age.RESULTS:
Gestational age decreased in a linear fashion from 1964 to 2007 with a decrease of 0.25 days per year in a similar way for MZ and DZ twins. Changes in birthweight depended on gestational age up to 32 weeks, birthweight decreased and after 32 weeks birthweight increased. The frequency of infertility treatment and Caesarean sections, primiparity and advanced maternal age increased over the years, but none of these factors influenced the secular trends in gestational age and birthweight.CONCLUSIONS:
The decrease in gestational age and change in birthweight in twins are sources of concern, especially for very preterm twins, for whom birthweight decreased. For twins born after 32 weeks, an increase in birthweight was observed and this is very likely the explanation for the decrease in gestational age.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Gêmeos
/
Peso ao Nascer
/
Idade Gestacional
Tipo de estudo:
Etiology_studies
/
Incidence_studies
/
Observational_studies
/
Prevalence_studies
/
Risk_factors_studies
Limite:
Female
/
Humans
/
Male
/
Newborn
País/Região como assunto:
Europa
Idioma:
En
Revista:
Hum Reprod
Assunto da revista:
MEDICINA REPRODUTIVA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Holanda