21 Weeks Pregnant with Twins

Here’s what to expect when you are 21 weeks pregnant with twins:

Fetal Development

By 21 weeks in the twin pregnancy each of your twins averages 10″ (26 cm) from head to foot. They will have the following measurements:

Head circumference: 7.5″ (191 mm)
Abdominal Circumference: 6.6″ (168 mm)
Femur Bone Length (about from the waist to knee): 1.4″ (36 mm)

What to Expect

Typical weight gain for Mom at this point is between 1.25 to 2.0 pounds/week.

For more details on Mom’s health, see:
Mom & Baby at 21 Weeks Pregnant
Week by week Twins calendar: pregnancy in weeks 20-24

Pictures and Video

Here’s an ultrasound video of what you might see at 21 weeks pregnant with twins:

Belly picture at 21 weeks:
21 Weeks Pregnant with Twins Belly

If Your Twins Were Born This Week

Your twins are still very early and ahead of the 24 week milestone that is the viability of life threshold. Most twins born at 21 weeks do not survive. Those that do have major medical complications.

What to Prepare This Week

When Mom is 21 weeks pregnant with twins, talk about how you are going to pay for all those twin diapers. Your twins will go through hundreds of diapers in a matter of weeks. Plan now how you will handle that financial burden.

Dad’s Thoughts

Are you a first-time father? By the time Mom reaches 21 weeks pregnant with twins, you need to overcome your nerves and start visualizing how life will be with the twins. It will be hard, but you can do it!

Previous: 20 Weeks

Next: 22 Weeks

View entire Twin Pregnancy Week by Week

Sources

When You’re Expecting Twins, Triplets, or Quads: Proven Guidelines for a Healthy Multiple Pregnancy by Dr. Barbara Luke and Tamara Eberlein

Babycenter’s Average fetal length and weight chart

Please note that everything on this page is provided as general information and doesn’t imply specific medical advice, diagnosis or treatment. Always consult with your medical professional.

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Written by , author of The Dad's Guide to Twins