Why is 37 weeks full term for twins

This is a BETA experience. You may opt-out by clicking here. More From Forbes. Jul 31, , am EDT. Jul 24, , pm EDT. Jul 10, , am EDT. Jul 9, , am EDT. Jul 7, , pm EDT. Jul 6, , pm EDT. Edit Story. Sep 7, , pm EDT. Some other physician groups recommend delivery closer to 39 weeks with separate placentas.

To assess the optimal timing of twin deliveries, researchers analyzed data from 32 studies published within the past decade that included a total of 35, twin pregnancies. Most were twins with separate placentas, but in 5, pregnancies the twins shared a placenta.

Researchers assessed the rates of stillbirths as well as deaths within the first 28 days after deliveries at various gestational ages after 34 weeks. Review of 35, births concludes that delivery earlier than 36 weeks is not supported by evidence, while waiting until 38 weeks increases rate of stillbirth.

Twins should be delivered at 37 weeks — short of full term but not too short — for the best chance at survival, according to a study that analysed more than 35, births. The evidence did not support routine delivery before 36 weeks from the date of fertilisation, said research published in the BMJ medical journal. Current recommendations for twin births vary from 34 to 39 weeks, short of the normal 40 weeks of gestation, to lower the risk of still birth.

Where there is only one placenta, delivery should be considered at 36 weeks. So recommends a large international study published in the BMJ that also concludes there is no clear evidence to support routine delivery before 36 weeks of gestation. The findings give women expecting twins and the health professionals assisting them crucial information to help them plan for delivery.

Compared with singleton pregnancies, the risk of stillbirth and newborn deaths is higher in twin pregnancies. In an effort to minimize such risks, uncomplicated twin pregnancies are often delivered early.

However, there is little scientific evidence on what the optimal gestational age for delivering twins might be. Existing recommendations vary, and they range from timing delivery at weeks of gestation for twins that share the same placenta monochorionic twin pregnancies , and weeks for twins with two placentas dichorionic twin pregnancies.

To address this shortfall, the international team reviewed 32 studies on twin pregnancies that were published in the last 10 years and carried out a pooled analysis of their data. Altogether, the pooled data covered 35, twin pregnancies 29, dichorionic and 5, monochorionic. The team only included studies on uncomplicated twin pregnancies that reported rates of stillbirth and newborn deaths up to 28 days after birth at various gestational ages after 34 weeks, and they also took into account study design and quality to minimize bias.