Determining the accurate gestational age during pregnancy is crucial for proper prenatal care. Both transvaginal scans and normal ultrasounds have their own advantages and limitations.
Transvaginal scans are performed by inserting a probe into the vagina to get a closer look at the uterus and fetus. They are usually done in early pregnancy (up to around 12 weeks) as they provide clearer images due to their proximity to the uterus. These scans can accurately measure the crown-rump length (CRL) of the fetus, which helps estimate gestational age.
Normal ultrasounds, also known as abdominal or tummy scans, are performed by moving a transducer over the abdomen to capture images of the uterus and fetus. They are commonly used after 12 weeks of pregnancy when the uterus rises above the pelvic bone. While these scans may not provide as detailed images as transvaginal scans in early pregnancy, they can still give an estimate of gestational age based on various fetal measurements.
In your case, it's important to consider that there can be slight variations in estimating gestational age between different doctors or ultrasound machines. Additionally, fetal growth rates can vary among individuals. It's possible that your baby is growing well but measuring slightly smaller or larger than expected.
To determine which scan is more accurate in your situation, it would be best to consult with your healthcare provider who has access to both scan results. They can compare the measurements and provide a more informed assessment of your gestational age.
Remember, ultrasound scans are not 100% precise in determining gestational age, and there can be a margin of error of around 1-2 weeks. Your healthcare provider will consider multiple factors, including your last menstrual period and any other relevant information, to determine the most accurate estimate of your pregnancy weeks.