What causes twin discordance?

The causes of twin growth discordance are often unknown. The most important is considered to be monochorionicity, mainly because of unequal sharing, or of velamentous cord insertions in the IUGR twin [20]. Other possible causes are “intrauterine crowding” and the presence of malformations [21-23].

When do you deliver discordant twins?

The median gestational age of delivery for the discordant twins was 34 weeks (29-38). Abnormal umbilical artery doppler informed delivery decision in 7 pairs, all of whom survived. The ductus venosus was used to inform decision in 2 sets of twins, of which only one baby survived.

How do you calculate discordance with twins?

Birth weight discordance =(larger twin weight−smaller twin weight) / larger twin weight×100.

What are the ultrasound criteria for discordant growth in monochorionic twinning?

Conventionally, sFGR is a term applied to twin pregnancies in which one fetus has an EFW < 10th centile and the intertwin EFW discordance is > 25a,62. The American College of Obstetricians and Gynecologists considers a difference of 15–25% in the EFW to constitute discordant fetal growth63.

How much weight difference between twins is normal?

The average birth weight of full-term twins (37 weeks or later, compared to 39-40 weeks for singletons) is around 5 ½ pounds each, though one baby often weighs more than the other.

What is it called when twins have different fathers?

In rare cases, fraternal twins can be born from two different fathers in a phenomenon called heteropaternal superfecundation. Although uncommon, rare cases have been documented where a woman is pregnant by two different men at the same time.

Are twins born the same weight?

Are Mono Di twins hereditary?

Spontaneous monozygotic twins happen by chance. Monozygotic twins do not usually run in families, although there are certainly families with a larger-than-expected number of monozygotic twins, suggesting genetics may sometimes play a role.

What is normal twin discordance?

Twin growth discordance is a term used in obstetric imaging to describe a significant size or weight difference between the two fetuses of a twin pregnancy. To be classified as a growth discordance, some consider that the estimated fetal weight (EFW) of the smaller twin should fall under the 10th centile.

How do you date twins on ultrasound?

Twin pregnancies should ideally be dated when the crown–rump length (CRL) measurement is between 45 and 84 mm (i.e. 11 + 0 to 13 + 6 weeks of gestation) (GRADE OF RECOMMENDATION: D).

What is discordant growth?

What is a good birth weight for twins?

The average birth weight of full-term twins (37 weeks or later, compared to 39-40 weeks for singletons) is around 5 ½ pounds each, though one baby often weighs more than the other. Because of the additional weight, twin pregnancies tend to be more uncomfortable.

What does it mean to have twin growth discordance?

Twin growth discordance. Twin growth discordance is a term used in obstetric imaging to describe a significant size or weight difference between the two fetuses of a twin pregnancy. To be classified as a growth discordance, some consider that the estimated fetal weight (EFW) of the smaller twin should fall under the 10 th centile.

When do you find out if your twins are discordant?

Growth discordance can be estimated by measuring the crown-rump length at or before 12 weeks of gestation. During the second and third trimesters, however, ultrasound measures are best used to estimate fetal weight and the degree of birth weight discordance.

How to calculate birth weight discordance for twins?

Calculation of Twin Birth Weight Discordance Birth weight discordance = (larger twin weight−smaller twin weight) / larger twin weight×100.

How many Twins in the world are discordant?

Approximately 16% of twin gestations have discordance of at least 20%. We identified 14 risk factors for divergent growth that can be categorized as maternal, fetal, or placental.