Twin-Specific Intrauterine ‘Growth’ Charts Based on Cross-Sectional Birthweight Data

Abstract

The assessment of fetal growth is an essential component of good antenatal care, especially for twins. The aims of this study are to develop twin-specific intrauterine 'growth' charts, based on cross-sectional birthweight data, for monochorionic and dichorionic twins according to sex and parity, and to detect twins at risk for neonatal death by comparing the use of twin-specific and singleton charts. The study sample consisted of 76,471 singletons and 8454 twins (4227 pairs) born in East Flanders (Belgium). Birthweights were analyzed using a nonlinear Gaussian regression. After 33 weeks of gestation, the birthweights of twins started to deviate from singletons (difference of 900 grams at 42 weeks). Birthweights of dichorionic twins continued to increase, whereas those of monochorionic twins decreased after week 40 (difference of more than 300 g at 42 weeks). After 31 weeks of gestation, neonatal mortality increased as centile decreased, and was especially high if birthweight was below the twin-specific third centile: .032 (below) versus .007 (above). Using singleton centiles, this was less obvious. In conclusion, twin-specific growth charts, taking chorionicity into account, are more accurate to detect twins at risk for neonatal death. Therefore the presented charts, based on cross-sectional birthweight data, enable an improved assessment of twin growth.

Lessons from BWS twins: complex maternal and paternal hypomethylation and a common source of haematopoietic stem cells

“…Data on placentation were obtained, when available, from the original pathological report of the placenta. Birthweight centiles were calculated according to Gielen et al 29 Zygosity was established with the use of PowerPlex 16 (Promega Corporation, Madison, WI, USA). Zygosity testing was performed on DNA isolated from buccal swabs when available; in all other cases, it was performed on DNA isolated from blood lymphocytes.…”

“…Although in almost all cases the genetic defect is demethylation of DMR2, relative birthweight centiles were calculated for or against twin referents. 29 Of the three major criteria, macrosomia (birthweight above birth weight centile P9), macroglossia and abdominal wall defects, macrosomia was present only in 5 of the 11 affected twins (twins 6, 7, 11 and 13). In 4 of 10 cases, the unaffected twin had a higher birthweight compared with the affected twin (twins 1, 3B, 9 and 10).…”

Health care supervision for twin pairs

“…Other studies have demonstrated reduced weight gain after the 32nd week of pregnancy, but reduced height gain only after week 39 [van Dommelen et al, 2008] Belgian twin pregnancies were used to create prenatal ''growth curves,'' used to monitor growth throughout the pregnancy, and to predict those at risk of neonatal death. [Gielen et al, 2008].…”

Infant mortality in twin pregnancies following in-utero demise of the co-twin

“…Twin pregnancies are high-risk gestations with elevated perinatal mortality rates [1] . Twins, when compared with singletons, have a five-fold risk of fetal death, seven-fold elevated risk of neonatal death, and five-fold risk of infant death [2][3][4] .…”

“…Twins also respond differently from singletons to interventions that are designed to lengthen the gestational age at birth [5,6] . Factors that impact fetal mortality risks include prenatal complications, maternal age, poor obstetric history and Assisted Reproductive Technology (ART) [1][2][3][4][5][6]. Twins face greater risks for low birth weight, preterm birth, long-term disability and early death than singletons [7].…”