Estimated Fetal Weight by Third Trimester Ultrasound…..What To Do?

Say What

I’ve seen it all too often, a pregnant mom gets a third trimester ultrasound, for whatever reason…..part of antepartum testing because she has passed her due date, we suspect that baby is “big”, or, we just randomly got it because the patient wants to see the baby and make sure that everything is ok. Some patients even get someone with a portable ultrasound to do it for them to make sure of this.

The ultrasound report comes back stating that baby is BIG!

OMG! What to do? Well here’s what NOT to do…..

DON’T have a c-section or proceed with an induction(specifically if you’re not 39 weeks and your cervix is not favorable) based SOLELY on a third trimester estimated fetal weight obtained by ultrasound! I see this ALL the time. Pregnant moms freaking out because the ultrasound said their baby was going to weigh 9 pounds some ounces……

PUMP YOUR BRAKES!!!!! I typically will offer my patients a c-section if you are diabetic and your estimated fetal weight is 4500 grams OR if you are non-diabetic and your estimated fetal weight is 5,000 grams. Otherwise, you CAN undergo a trial of labor. If you start falling off the labor curve and aren’t making the sort of “changes” that are typical of labor; i.e., you’re not dilating, baby isn’t descending into the pelvis, etc., you and your ob/gyn should/will talk.

In all honesty, an estimated fetal weight obtained by ultrasound in the third trimester is no better than bedside Leopold’s maneuvers(where your OB/GYN feels your gravid uterus not only to palpate the position of baby, but also to guestimate how much baby is going to weigh).

Through YEARS of experience, I’ve actually gotten to be pretty darn good at estimating fetal weight by “feel”…….I guess you could say “THE FORCE IS STRONG” with me in that way.

I’ve said all of the above to say this, as a complete throwback to Digital Underground, “Do What You Like”!

Don’t let fear be the determining factor. Don’t have an elective cesarean section based solely on an ultrasound estimate(while they can occasionally be correct, I’ve seen them WAAAAAAAY off; i.e., 9 pound estimates by ultrasound only to be 7 pounds some ounces at the time of c-section….see what I’m sayin’?)

Know ALL the facts! Risks, benefits, pros, cons. Ask questions. Got it?!?!?

Until Next Time,

Look Better. Feel Better. Be Better.

Dr. Angela

About Dr. Angela

Wife, mother, Midwesterner, and award-winning OB/GYN, Dr. Angela is equal parts best girlfriend and bold professional, supporting women’s health with innovative approaches to care and heavy doses of humor. Dr. Angela has done more than launch a successful practice, she has defined herself as a voice for a new generation of womanhood, established her ASK DR. ANGELA brand committed to authenticity, and built a community rooted in trust, candor, and compassion.

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