AIMS: (1) To investigate the association between birth weight and anthropometric measurements during adulthood; (2) to study the genetic and environmental influences on body measures including birth weight, weight and height among twins; and (3) to assess the variation in heritability versus environment among two cohorts of twins who lived in different geographical areas.

SUBJECTS AND METHODS: Twins were collected from two twin registers. Data on birth weight, adult weight and height in 430 MZ and 170 DZ twins living in two geographically distinct parts of the world were collected. A genetic analysis was performed using MX software.

RESULTS: Birth weight was associated with weight, height and BMI. Both MZ and DZ twins with low birth weight had shorter height during their adult life (p = 0.001), but only MZ twins with lower birth weight were lighter at adulthood (p = 0.001). Intra-pair differences in birth weight were not associated with differences in adult height (p = 0.366) or weight (p = 0.796). Additive genetic effects accounted for 53% of the variance in weight, 43% in height and 55% in birth weight. The remaining variance was attributed to unique environmental effects (15% for weight, 13% for height and 45% for birth weight and only 16% for BMI). Variability was found to be different in the two cohorts. The best fitting model for birth weight and BMI was additive genetic and non-shared environment and for weight and height was additive genetic, non-shared environment (plus common Environment).

METHODS: The study was a retrospective cohort study in a single tertiary centre in Malaysia from 2014 until 2018 involving all twin pregnancies delivered at or more than 24 weeks of gestation.

RESULTS: Total of 409 twin pregnancies were included. Dichorionic twin comprises of 54.5 % (n=223) and 45.5 % (n=186) are monochorionic. Women with dichorionic pregnancies are significantly older (p<0.001), have more pre-existing medical disorders (p=0.011) and fetal structural anomalies (p=0.009). Monochorionic pregnancies are significantly more amongst Malay (p=0.01) and conceived spontaneously (p<0.001). There are significantly more fetuses both in cephalic presentation (p=0.026), birthweight discrepancy more than 20 % (p=0.038) and shorter mean inter-twin delivery duration (p=0.048) in monochorionic pregnancies. Second twin delivered with Apgar score <7 is significantly more in dichorionic pregnancies (p=0.006). The second twin is associated with lower birthweight, small for gestational age and arterial cord pH<7.25. Within the group of women who delivered both fetuses vaginally, there was significantly more second twins with intertwin delivery duration less than 30 min who were delivered vaginally without instrumentation (p=0.018). There was significantly more second twin with intertwin delivery duration of 30 min and more with arterial cord pH<7.25 (p=0.045). Those who delivered spontaneously had inter-twin delivery duration within 15-29 min. The outcome of second twin is not influenced by type of twin, gestational age at delivery, inter-twin delivery duration, mode of delivery and presentation at birth.

MATERIALS AND METHODS: A retrospective cross-sectional study was carried out on 645 women with DC twins, excluding pregnancies complicated by one or both fetuses with demise (n = 22) or congenital anomalies (n = 9), who gave birth after 28 complete gestational weeks between 1 January 2001 and 31 December 2018. Univariable and multiple logistic regression analyses were carried out.

RESULTS: Maternal age >34 years (adjusted odds ratio 2.52; 95% confidence interval 1.25-5.07) and pre-pregnancy body mass index >24.9 kg/m2 (adjusted odds ratio 2.83, 95% confidence interval 1.47-5.46) were independent risk factors for GDM in women with DC twins. Newborns from women with GDM DC twins were more likely to be admitted to the neonatal intensive care unit (adjusted odds ratio 1.70, 95% confidence interval 1.06-2.72) than newborns from women with non-GDM DC twins. Other pregnancy and neonatal outcomes were similar between the two groups.

MATERIALS AND METHODS: This is an observational cohort study and retrospective case assessment, involved twins born at Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan between 2013 and 2018. DC twins with selective IUGR (sIUGR) were defined as the presence of a birth weight discordance of >25% and a smaller twin with a birth weight below the tenth percentile. PDA was diagnosed using echocardiography between postnatal day 3 and 7. Hs-PDA was defined as PDA plus increased pulmonary circulation, poor systemic perfusion, cardiomegaly, pulmonary edema, or hypotension requiring pharmacotherapeutic intervention.

RESULT: A total of 1187 twins were delivered during the study period, and 53 DC twins with selective IUGR were included in this study. DC twins with PDA have higher rate of preterm birth, lower gestational age of delivery, and lower mean birth weight of both twins compared with DC twins without PDA. In a comparison of the sIUGR twin with the appropriate for gestational age co-twin, both the incidences of PDA (28.30% vs. 7.55%, respectively; P = 0.003) and Hs-PDA (24.53% vs. 5.66%, respectively; P = 0.002) were higher in sIUGR fetuses than in the appropriate for gestational age co-twins. Small gestational age of delivery was the only variable to predict PDA and Hs-PDA [p = 0.002, Odds ratio = 0.57 (0.39-0.82), p = 0.009, Odds ratio = 0.71 (0.55-0.92), respectively].