About 50 percent of twins are born early. Twin delivery, on average, occurs around 35 to 36 weeks. Triplets and quadruplets may come even sooner. Moms of singletons, on average, deliver at 39 weeks. Since many twin births happen early, the average twin arrives weighing about 5 1/2 pounds.
While the average single baby weighs 7 pounds at birth, the average twin weighs 5.5 pounds. Triplets typically weigh 4 pounds each, and quads weigh 3 pounds each. Babies born at under 5.5 pounds are considered to have a low birth weight.
The average weight of twins is 2.5kg.
The Average Birthweight of Twins
Low birth weight is defined as less than 2,500 grams or 5 pounds, 8 ounces. Very low birth weight is defined as weighing less than 1,500 grams or 3 pounds, 5 ounces.
The heaviest birth weight for surviving twins on record goes to Mrs. J.P. Haskin of Arkansas, on February 20 1924, whose twins weighed in at an eye-watering 14lbs & 13lbs 12oz, totalling 27lb 12oz. The Uk's heaviest set appear to have been the Warren's born on December 6th 1884 totalling 25lbs 8ozs.
Previous studies of twins have reported that the second-born twin is, on average, lighter than the first-born twin at birth (Glinianaia et al., 2000; Gielen, et al., 2007; van Baal and Boomsma, 1998).
How much you should gain: If you're carrying twins and your weight was in the normal range (body mass index of 18.5 to 25) before conception, the American College of Obstetricians and Gynecologists (ACOG) recommends that you gain 37 to 54 pounds during your pregnancy.
Full-term for twins is the same as full-term for singleton babies, technically: 39 weeks pregnant. But if your twins are born at 37 weeks, that's as close to actual full-term as many twins get. At that point, they have full lung maturity and should be able to leave the hospital within a few days of delivery.
A little more than half of twin pregnancies end in preterm delivery (before 37 weeks). While 40 weeks is the full gestation period of the average pregnancy, most twin pregnancies are delivered at approximately 36 weeks (range 32-38 weeks depending on the type of twin pregnancy).
Conclusions: During the first 2.5 years of life, there is a difference in growth between twins and singletons. Twins catch up in their body size, i.e. they grow faster after birth, but do not yet achieve the same height and weight till they reach 2.5 years of age.
The mean birthweight slightly decreased from 2462 g in 2001 to 2440 g in 2010 for male twins (p = 0.49). For female twins, the mean birthweight significantly decreased from 2375 g in 2001 to 2338 g in 2010 (p < 0.001) (Fig. 2).
They conclude, “In terms of short- and long-term outcomes, uncomplicated twin pregnancies should not be delivered before 37 completed weeks of gestation and that there is a limited benefit of prolonging pregnancy after that.”
Studies also show that twins are more likely to suffer from specific health disorders. While they represent just 2 percent of the general population, twins make up 7.4 percent of the nation's cerebral palsy sufferers.
Multiples are undergoing the same developmental changes as singletons during this period of gestation, but most multiples have already been delivered at this stage. Your babies have most likely reached their full height by now, though they continue to gain about an ounce each day.
Twins are known to be smaller than singleton babies, but up until recent years, routine use of singleton growth charts to plot the growth of twins were still being used.
A typical, single pregnancy lasts about 40 weeks, but a twin pregnancy often lasts between 35 to 37 weeks. More than half of all twins are born prematurely (before 37 weeks), and the risk of premature delivery increases with higher-order multiples. Premature babies (preemies) can have health challenges.
The birth process is similar to giving birth to a single baby. If you're planning a vaginal birth, your health team may recommend that you have an epidural for pain relief.
Twin delivery, on average, occurs around 35 to 36 weeks. Triplets and quadruplets may come even sooner. Moms of singletons, on average, deliver at 39 weeks. Since many twin births happen early, the average twin arrives weighing about 5 1/2 pounds.
The median twin-to-twin time interval was 19 min (range 2–399) with 217 (41.2%) of the second twins being born within 15 min, 143 (27.1%) second twins were born within 16–30 min, 70 (13.3%) within 31–45 min, 37 (7%) within 46–60 min and 60 (11.4%) after 60 min.
36-37 weeks if you are carrying twin babies that share a placenta (monochorionic) between 32 and 33+6 weeks if you are carrying twin babies that share a placenta and amniotic sac (monochorionic monoamniotic)
With the placenta(s) in multiple pregnancies covering a greater proportion of the uterine wall, there is a higher risk of complications that can be dangerous for mom or babies. Placental abruption or placenta previa are some situations that might prompt an early delivery.
You may have even heard that people pregnant with multiples always have a c-section. The truth is, about 50 percent or more of twins are born vaginally. When pregnant with twins, there are multiple variables that determine the safest way to give birth.
If your pre-pregnancy BMI was between 18.5 and 24.9, you should gain between 16kg and 24kg. If your pre-pregnancy BMI was between 25 and 29.9, you should gain between 14kg and 23kg. If your pre-pregnancy BMI was 30 or above, you should gain between 11kg and 19kg.
Total weight gain of 16 to 20.5 kg (35 to 45 lb) is consistent with a favorable outcome of a full-term twin pregnancy. This suggests that a woman who is pregnant with twins should aim for a weekly weight gain of approximately 0.75 kg (1.5 lb) during the second and third trimesters of pregnancy.
One can say that a twin belly will be 20% larger than a single pregnancy belly. Sometimes, mothers won't even notice that they're carrying twins, regardless of the size of their bellies.