32 weeks pregnant © 2014 by Lucas & Whitney Shaffer. Used with permission.
The Third Trimester of Pregnancy – Weeks 29-40
By Serena D. Tidwell M.D, Midtown OB/GYN
The third trimester of pregnancy is an exciting but tiring time!
Typical visits for the third trimester are during weeks 30, 32, 34, 36 and then weekly after the 36th week. Usual screening tests during the third trimester are Group B Strep, commonly referred to as “GBS”. The GBS swab is collected with a vaginal and rectal swab to detect if a Mom carries GBS bacteria. About a third of all women are carriers; it is not an abnormal finding. However, it does indicate the need for antibiotics during labor if you are a carrier. For Moms who have a C-Section it is still important information for your Pediatrician. GBS is primarily a cause of infection for preterm infants; however, with universal screening we can eliminate those rare term infections.
At Midtown OBGYN we perform an ultrasound at 37-38 weeks to verify that the baby is head down and to obtain an estimated fetal weight. I will often have patients tell me that they read or heard that their baby will gain a half pound a week during the third trimester. While this is true after 36 weeks, it is not true prior to that. This is why the ultrasound at 37-38 weeks can be helpful in predicting birth weight.
34 weeks is the milestone after which we do not stop labor if patients go into labor early. During the third trimester, we still need to be on the lookout for preterm labor symptoms. Over the past few years, there has been a big push to try to reduce the number of elective deliveries prior to 39 weeks. The reason for this is that some babies prior to 39 weeks will have prematurity problems. There are many resources which explain this initiative – the reference from the American College of OBGYN is a good one: http://www.acog.org/-/media/For%20Patients/faq181.pdf.
I think the biggest challenge as a patient approaches their due date is delivery planning. I like to meet with my patients after the 37-38 week ultrasound and ask if they had a magic wand to plan their delivery what would the delivery look like. Most patients by this time have personal preferences about whether they prefer a vaginal delivery, a C-Section and whether or not they want to be induced. It is important to remember that inductions increase the risk of C-Section, especially with first babies. While this can’t be controlled with medically indicated situations (Preeclampsia, Gestational Diabetes, etc) it can be controlled with elective indications for delivery.
Also, remember to pack your hospital bag around 34-35 weeks just in case. A usual hospital stay for vaginal delivery is 2 days after the baby is born and for C-Section 2-3 days after baby is born. If you plan to breast feed, I would strongly suggest making a follow up appointment with the lactation consultant prior to leaving the hospital.
Dr. Serena Tidwell is an OB/GYN with Midtown OB/GYN. She completed residency at Wake Forest University after graduating from The Medical College of Georgia and Emory University. She is the 2013 winner of our Choice Award for Best OB/GYN.
Image Source: Whitney & Lucas Shaffer. Used with Permission
