Using Geeky Skills to Make Predictions

From the Twin-Daddy:

Hunter-Gatherer checks his calculations

Today is Twin Day, and we are 33 weeks along and 3 weeks from hitting our goal of 36 weeks.  As Mary indicated, we had a big surprise when we got a look at the boys and found out that they were ahead of schedule again weighing in at about 6 pounds each.

I am an engineer by trade, and we have been collecting a good bit of data.  Using the length measurements and the average baby sizes from babycenter.com, I was able to estimate weights based on length measurements and estimated gestational age from each ultrasound we have had over the course of the pregnancy.  It is important to remember that some of these weight numbers are calculated from average gestational age.  Even the measured ultrasound weights can have a margin of error of plus or minus 15%.

Plugging in the data, what we got was an exponential curve that significantly outpaced a typical singleton baby.  You can see how each boy is growing in this chart:

Little Boy Growth Chart -- (Click for larger view)

Aside from reaching 36 weeks with the boys, Mary’s other goal has been to get the guys to 6 pounds each. Now that they’ve reached that initial goal, she’s eyeing 7 pounds each.  If their average growth rate continues as it is, how long will that take them?

7 pounds = 3175 grams

Alex and Dominic at current weights:

• Alex = 2805 grams
• Dominic = 2643 grams

In the last 4 weeks each of our boys gained weight as shown:

• Alexander gained 1252 grams
• Dominic gained 951 grams

The average of these two weight gains is:

1252 + 951 = 2203 grams

2203 / 2 = 1101 grams

1101 grams / 28 days = 39 grams gained per day

Since Dominic has slipped out of first place and weighs slightly less now, we will use him as our benchmark for 7 pounds.  (If he reaches 7 pounds, we can assume his brother has also reached 7 pounds.)

Additional Weight Required to Reach 3175 grams (7 pounds):

• Alex = 370 grams
• Dominic = 532 grams

532 grams required/ 39 grams per day = 13.64 days until the boys reach 7 pounds

Round that up to 14 days to predict that we reach our target weight by August 5th.

Babies Countdown – The Double Header

42 days until September 2

14 days until 14-Pounder Day (August 5)

21 days until Median Day (August 12)

• Thursday, July 29 and after this day we deliver at the birthing center instead of in Sacramento.
• Friday, July 30 is our next appointment with the OB-GYN.
• Monday, August 2 is our wedding anniversary.
• Thursday, August 5 and we hit our goal of 7 pounds each at 35 weeks.
• Thursday, August 12 and we hit our goal of 36 weeks minimum. This is Median Day.
• Thursday, August 19 is our next (tentative) appointment with the perinators.
• Thursday, September 2 and the OB-GYN has said she doesn’t want Mary to carry beyond this date.
• Thursday, September 9 is our due date even if we know the twins will be here sooner.
• 2 weeks Post Delivery – Schedule a follow up appointment with the Lactation Lady.
• 4 Weeks Post Delivery – Look for baby smiles.
• After the Delivery – 4.5 months of the Twinsanity Interval.