Supertwins
Statistics
|
The
Average Multiple Birth Baby |
|
Multiple type |
Average weeks gestation |
Average infant birth weight |
Average days in NICU
(Neonatal Intensive Care Unit) |
NICU Range |
Average days in hospital |
Hospital Range |
Twins |
35.5 weeks |
5lbs 7oz |
3 days |
0 to 24 |
11 days |
2 to 56 |
| Triplets |
33.1
weeks |
4lbs
1oz |
19 days |
0 to 336 |
23 days |
0 to 336 |
| Quadruplets |
31.3
weeks |
3lbs
4oz |
31 days |
0 to 127 |
37 days |
0 to 150 |
| Quintuplets |
29.8
weeks |
2lbs
12oz |
47 days |
0 to 194 |
53 days |
4 to 384 |
| Sextuplets |
29.1
weeks |
2lbs
8oz |
56 days |
10 to 195 |
65 days |
32 to 119 |
For information about the NICU and multiples, see our Multiples in the NICU FAQs.
|
Average Birth Weights |
| Gestation |
Twins |
Triplets |
Quadruplets |
Quintuplets |
| <25
weeks |
|
2
lb 3 oz |
1
lb 6 oz |
1 lb 2 oz |
| 25 weeks |
|
1 lb 10 oz |
1 lb 10 oz |
1 lb 9 oz |
| 26
weeks |
|
1 lb 14 oz |
1 lb 11 oz |
1 lb 8 oz |
| 27
weeks |
|
2
lb 0 oz |
2
lb 4 oz |
1 lb 14 oz |
| 28
weeks |
|
2
lb 7 oz |
2
lb 4 oz |
2
lb 3 oz |
| 29
weeks |
|
2
lb 9 oz |
2
lb 7 oz |
2
lb 10 oz |
| 30
weeks |
3 lb 0 oz |
3 lb 0 oz |
2
lb 12 oz |
2
lb 11 oz |
| 31
weeks |
|
3
lb 5 oz |
3
lb 2 oz |
2
lb 14 oz |
| 32
weeks |
|
3
lb 10 oz |
3
lb 7 oz |
3
lb 7 oz |
| 33
weeks |
|
4
lb 0 oz |
3
lb 14 oz |
4
lb 6 oz |
| 34
weeks |
|
4
lb 6 oz |
4
lb 3 oz |
3
lb 14 oz |
| 35
weeks |
5
lb 10 oz |
4
lb 13 oz |
4
lb 11 oz |
|
| 36
weeks |
5
lb 2 oz |
5 lb
2 oz |
4
lb 14 oz |
5 lb 10 oz |
| 37
weeks |
7 lb 0 oz |
5
lb 5 oz |
5
lb 5 oz |
4
lb 5 oz |
| 38
weeks |
6
lb 3 oz |
5
lb 3 oz |
6 lb 2 oz |
|
| 39
weeks |
|
6
lb 0 oz |
|
|
(Note: most NICUs measure infants in grams not punds and ounces. To assist parents of infants
in the NICU, MOST provides an online weight
conversion tool that converts weights in grams into pounds and ounces as well as weights in pounds
and ounces into grams.)
| Multiple type and birth order |
Average days in the NICU |
| Twins |
|
| 1 |
3.5 |
| 2 |
3.3 |
| Triplets |
|
| 1 |
18.3 |
| 2 |
18.5 |
| 3 |
19.9 |
| Quadruplets |
|
| 1 |
28.4 |
| 2 |
29.0 |
| 3 |
30.7 |
| 4 |
36.6 |
Quintuplets |
|
1 |
40.7 |
2 |
43.1 |
3 |
46.5 |
4 |
54.0 |
5 |
57.9 |
Sextuplets |
|
1 |
73.3 |
2 |
45.7 |
3 |
49.8 |
4 |
43.5 |
5 |
53.0 |
6 |
64.5 |
| Average Days in the
NICU by Multiple Delivery Type and Birth Order |
| Birth Order |
Vaginal Delivery |
C-Section |
| Triplets |
|
|
| 1 |
29.8 |
17.8 |
| 2 |
23.6 |
18.3 |
| 3 |
22.6 |
19.7 |
| |
|
|
| Quadruplets |
|
|
| 1 |
44.0 |
27.7 |
| 2 |
33.8 |
28.8 |
| 3 |
14.7 |
30.8 |
| 4 |
38.7 |
36.5 |
|
| Average days in the NICU by Multiple Type and Gestation |
| Gestation |
Triplets |
Quadruplets |
Quintuplets |
| <25 weeks |
60.8 |
18.9 |
68.5 |
25 weeks |
113.5 |
90.0 |
83.0 |
| 26
weeks |
90.0 |
76.4 |
80.6 |
| 27
weeks |
82.0 |
52.9 |
75.8 |
| 28
weeks |
55.2 |
63.4 |
58.3 |
| 29
weeks |
46.9 |
47.9 |
49.0 |
| 30
weeks |
39.6 |
39.2 |
48.5 |
| 31
weeks |
30.7 |
28.6 |
38.3 |
|
32
weeks |
22.6
|
24.5 |
30.2 |
| 33
weeks |
16.8 |
18.3 |
7.0 |
| 34
weeks |
11.4 |
8.5 |
20.2 |
|
35
weeks |
6.2 |
8.1 |
|
| 36
weeks |
3.0 |
5.7 |
2.0 |
|
37
weeks |
3.5 |
0.2 |
|
38 weeks |
9.3 |
|
|
|
|
|
|
|
Gender and Zygosity |
|
Multiples |
Male |
Female |
No Answer |
Identical |
Fraternal |
Combined |
Unknown |
| Twins |
38.5% |
61.5% |
|
15.4% |
84.6% |
n/a |
0% |
| Triplets |
49.4% |
49.5% |
1.06% |
2.9% |
80.7% |
11.6% |
4.9% |
| Quadruplets |
46.1% |
46.8% |
7.08% |
0.4% |
84.0% |
9.6% |
6% |
| Quintuplets |
48.4% |
39.9% |
11.63% |
0% |
76.7% |
15.5% |
7.8% |
| Sextuplets |
14.3% |
50.0% |
35.71% |
0% |
100% |
0% |
0% |
For information about multiple birth zygosity, see MOST FAQs #17, #18, and #19.
| Average Gender Differences in Weight |
|
Multiple Type |
Females
|
Males
|
|
Twins |
5 lbs 1 oz |
6 lbs 1 oz |
|
Triplets |
4 lbs 0 oz |
4 lbs 3 oz |
|
Quadruplets |
3 lbs 5 oz |
3 lbs 5 oz |
|
Quintuplets |
2 lbs 7 oz |
2 lbs 15 oz |
|
Sextuplets |
2 lbs 6 oz |
2 lbs 10 oz |
8% of the multiple birth infants in this survey were transferred
to another hospital's NICU.
|
Infant Complications/Treatments |
Triplets |
Quadruplets |
Quintuplets |
Sextuplets |
| Death |
0.84% |
3.28% |
8.53% |
0.00% |
| Gastro
esophageal reflux |
1.64% |
2.75% |
4.65% |
2.38% |
| Gavage/IV
feeding |
57.21% |
70.19% |
73.26% |
61.90% |
| Heart
defect |
4.10% |
5.07% |
9.69% |
4.76% |
| Hernia |
7.19% |
10.78% |
15.89% |
16.67% |
| Infection |
3.48% |
5.07% |
3.49% |
2.38% |
| Intraventricular
hemorrhage (IVH) |
3.53% |
6.34% |
9.30% |
2.38% |
| Intubation
for 24+ hours |
23.54% |
34.67% |
43.41% |
50.00% |
| Jaundice |
51.04% |
59.51% |
58.91% |
47.62% |
| Meningitis |
.29% |
.53% |
0.00% |
0.00% |
| Necrotizing
enter colitis (NEC) |
1.44% |
2.22% |
1.55% |
2.38% |
| O2 after discharge |
.40% |
.32% |
.39% |
0.0% |
| O2 in the NICU |
6.39% |
7.93% |
9.30% |
0.0% |
| Other |
3.31% |
3.38% |
5.04% |
2.38% |
| Periventricular
leukomalasia (PVL) |
.24% |
.74% |
.39% |
0.0% |
| Retinopathy
of Prematurity (ROP) |
4.86% |
10.57% |
14.73% |
19.05% |
| Seizures |
.35% |
.63% |
1.16% |
0.0% |
| Surfactant
treatment |
15.77% |
20.40% |
29.07% |
45.24% |
| Surgeries |
5.17% |
9.83% |
13.57% |
9.52% |
| Transfusions |
16.19% |
27.48% |
44.19% |
54.76% |
For more information about infant multiples, Infant Multiples Page, Infant Multiples FAQ, and consider purchasing the MOST Infant Multiples packet.
