Blog

Pregnancy brings a steady stream of questions, and finding clear, clinically grounded answers can make an enormous difference in how expectant parents experience each week of care. In a recent episode of the podcast Healthful Woman, Dr. Nathan Fox addressed a wide range of listener questions about pregnancy, covering topics from fetal growth percentiles and kidney findings to Braxton Hicks contractions and glucose screening. The discussion is a valuable resource for anyone navigating a pregnancy and trying to make sense of what ultrasound findings, screening results, and physical symptoms actually mean. If you have questions specific to your own pregnancy, our team is available to help. Call for details to schedule a consultation.

What Dr. Nathan Fox Says About Fetal Growth and Common Ultrasound Findings in Pregnancy

One of the most common sources of anxiety during pregnancy is an ultrasound report that shows a baby measuring outside the expected range. In the podcast episode, Dr. Fox addressed a listener whose baby was measuring in the seventh percentile for size. He noted that a baby in the seventh percentile is not automatically cause for concern. According to Dr. Fox, the context matters: a baby who has been consistently small throughout pregnancy, with normal blood flow on Doppler studies and no structural abnormalities, may simply be constitutionally small. The key question, he explained, is whether the growth pattern is stable or whether there is evidence of growth restriction.

Dr. Fox also discussed pyelectasis, a mild widening of the renal pelvis in the fetus that is sometimes identified during a routine OB/GYN ultrasound consultation. He explained that mild pyelectasis is a relatively common incidental finding and is often benign, though it warrants follow-up imaging to monitor whether it resolves or progresses. He noted that isolated mild pyelectasis, without other markers, is generally not a reason for significant concern.

These are exactly the kinds of nuanced findings where specialist expertise adds real value. Our physicians are board-certified in Maternal Fetal Medicine, and our sonographers hold full registration as Diagnostic Medical Sonographers with specialty certification in OB/GYN imaging. All scans are performed using state-of-the-art 3D/4D ultrasound technology, which supports more detailed evaluation of the findings Dr. Fox described. For further reading on prenatal diagnostic topics, our blog covers a range of evidence-based pregnancy subjects.

Pregnancy Questions Answered: Braxton Hicks Contractions and Large-for-Gestational-Age Findings

Dr. Fox devoted a portion of the episode to Braxton Hicks contractions, which are irregular uterine contractions that many patients experience during pregnancy, particularly in the second and third trimesters. He described them as a normal physiological occurrence, explaining that the uterus practices contracting throughout pregnancy. The distinction between Braxton Hicks and true labor contractions, he noted, lies in their pattern: Braxton Hicks tend to be irregular, do not increase in frequency or intensity over time, and typically resolve with rest or hydration. True labor contractions follow a more consistent pattern and progress in duration and strength.

The episode also addressed large-for-gestational-age (LGA) babies, a finding that can raise questions about delivery planning and maternal health. Dr. Fox explained that LGA estimates from ultrasound carry a margin of error and that clinical context, including maternal history, glucose tolerance, and growth trajectory, informs how providers interpret and respond to these findings. He emphasized that a single measurement alone rarely drives major clinical decisions.

Patients who have received an LGA finding or who are concerned about gestational diabetes may benefit from a high-risk pregnancy consultation with a specialist. Our practice also offers a dedicated Gestational Diabetes Support Program, which provides individualized guidance for patients managing glucose-related concerns during pregnancy.

Core Exercise and Glucose Screening During Pregnancy: What the Evidence Suggests

Two practical questions addressed in the podcast touched on lifestyle factors during pregnancy. The first involved core exercise. Dr. Fox explained that, for most uncomplicated pregnancies, core strengthening exercises are generally considered safe and may support musculoskeletal comfort as the body changes. He noted that modifications are typically recommended as pregnancy progresses, and that patients should discuss their specific exercise routines with their individual providers, particularly if any complications are present.

The second question concerned whether diet in the days before the one-hour glucose challenge test can affect the result. Dr. Fox addressed this directly, noting that while some practitioners advise patients to avoid unusually high-sugar intake in the day or two before the test, the standard one-hour glucose challenge is designed to assess the body’s metabolic response under typical conditions. A single high-carbohydrate meal is unlikely to change a result in someone without underlying glucose regulation concerns, but he acknowledged that this is a topic patients frequently ask about.

For patients who receive a result that warrants further evaluation, our team includes registered dietitian Casey Seiden, who provides dietitian services tailored to pregnancy nutrition and metabolic health. Our publications page also contains clinical references that may be useful for patients who want to read further on these topics.

Why Choose Our Practice for Your Pregnancy Care?

Our practice partners with Mount Sinai West and maintains a team of board-certified Maternal Fetal Medicine specialists supported by fully Registered Diagnostic Medical Sonographers with specialty certification in OB/GYN imaging. Every ultrasound scan is performed using advanced 3D/4D technology, and our physicians and sonographers are fully certified to perform Nuchal Translucency Assessment, including Nasal Bone imaging. Board-certified MFM specialists are available on site to perform Chorionic Villous Sampling and Amniocentesis when indicated, and fully certified Genetic Counselors are available for consultations as needed.

For patients navigating the kinds of questions Dr. Fox discussed in the podcast, our team provides thorough, individualized evaluation grounded in current clinical evidence. We welcome patients from throughout the region who are seeking specialist-level pregnancy care. To read what patients say about their experience with our practice, visit our online patient reviews page.

Frequently Asked Questions

What does it mean if my baby is measuring in the seventh percentile during pregnancy?

A baby measuring in the seventh percentile is not automatically a sign of a problem. According to Dr. Nathan Fox on the Healthful Woman podcast, consistent growth trajectory, normal Doppler blood flow, and the absence of structural findings all factor into how providers interpret size. Individual results may vary, and a specialist consultation can provide more context based on your specific pregnancy history.

Is mild pyelectasis in the fetus something to be concerned about during pregnancy?

Mild pyelectasis, or slight widening of the fetal renal pelvis, is a relatively common finding on prenatal ultrasound. Dr. Fox noted in the episode that isolated mild pyelectasis is often benign and frequently resolves on its own, though follow-up imaging is typically recommended to monitor the finding. Your provider can advise on the appropriate interval for follow-up based on the specific measurement.

How can I tell the difference between Braxton Hicks contractions and labor contractions during pregnancy?

Dr. Fox explained that Braxton Hicks contractions are typically irregular and do not increase in frequency, duration, or intensity over time. True labor contractions tend to follow a consistent pattern that progressively intensifies. Rest and hydration often ease Braxton Hicks episodes. If you are uncertain about what you are experiencing, contact your obstetric provider for guidance.

Does what I eat before the glucose challenge test affect my result during pregnancy?

Dr. Fox addressed this question directly, noting that the one-hour glucose challenge is designed to assess metabolic response under typical dietary conditions. While avoiding unusually high sugar intake beforehand is sometimes recommended, a single meal is unlikely to meaningfully alter results in patients without underlying glucose regulation concerns. Your provider can advise on any specific preparation instructions for your test.

Are core exercises safe to continue during pregnancy?

For most patients with uncomplicated pregnancies, core strengthening exercises are generally considered safe, according to Dr. Fox. Modifications are typically recommended as pregnancy progresses, and patients with any pregnancy complications should consult their provider before continuing or starting a core exercise program. Individual circumstances vary, and personalized guidance from your care team is always the most appropriate approach.

If you have questions about your pregnancy, our board-certified Maternal Fetal Medicine specialists are here to help. Call for details to schedule a consultation with our team, or contact us online to request an appointment. Individual results may vary, and all care recommendations are based on your specific clinical history.

Carnegie Imaging for Women blogs are intended for educational purposes only and do not replace certified professional care. Medical conditions vary and change frequently. Please ask your doctor any questions you may have regarding your condition to receive a proper diagnosis or risk analysis. Thank you!