How to count your pregnancy in weeks and months
Petrina is an enthusiastic and caring Sonographer with 20 years experience in obstetrics and gynaecological ultrasound. With her love of obstetric scanning and patient contact she lectures and tutors future Sonographers at the Australian Institute of Healthcare Education. Petrina is also a wife and busy mum to two boys, where together as a family, they love spending time outdoors. That first appointment with the sonographer can be a little daunting, but it’s an important time to gather some key information about your growing baby.
Congratulations, you have found out you are pregnant, and the first scan in your pregnancy should be an exciting time. Walking into the ultrasound room, you will be full of mixed emotions.
What tests you need if your baby does not show on a scan, what precautions to take and the support available.
A dating scan is an ultrasound examination which is performed in order to establish the gestational age of the pregnancy. Most dating scans are done with a trans-abdominal transducer and a fullish bladder. If the pregnancy is very early the gestation sac and fetus will not be big enough to see, so the transvaginal approach will give better pictures. Dating scans are usually recommended if there is doubt about the validity of the last menstrual period.
By 6 to 7 weeks gestation the fetus is clearly seen on trans-vaginal ultrasound and the heart beat can be seen at this early stage 90 to beats per minute under 6 to 7 weeks, then to beats per minute as the baby matures. Ultrasounds performed during the first 12 weeks of pregnancy are generally within 3 – 5 days of accuracy. The most accurate time is between 8 and 11 weeks gestation. This is because the fetus is growing so quickly that there is a big difference in size from week to week.
However, the accuracy of the ultrasound examination is always dependent on the skill of the sonographer and the quality of the equipment.
Your Due Date Is Wrong.
MFM mums share their stories plus expert sonographers explain why it happens and what to do if you’re told your due dates are wrong. By Rachel Mostyn. Original date given was 18 December but at the scan it was moved to 31 Dec. Unless you have an early pregnancy scan most of you will be given your estimated due date at the week scan. Of course you have probably already used an online due date calculator.
A dating scan is an ultrasound scan to determine how many weeks pregnant you are and your due date. pregnancy discomforts · Complications during pregnancy · If things go wrong The scan will take 5 to 10 minutes to perform. to think about the month in which you are expecting your baby, rather than the exact day.
Log in Sign up. Community Groups Birth clubs I’m pregnant! My pregnancy journal Pregnant with twins or more Baby names See all pregnancy groups. Home Pregnancy Pregnancy health Ultrasound scans. Your doctor calculates your stage of pregnancy or your gestational age using your last menstrual period LMP. She will ask you when the first day of your last period was and from there, count how many weeks pregnant you are.
Accuracy of Pregnancy Ultrasound to Predict the Due Date
Pregnant woman holding the scan of her baby. If you can’t remember the date of your last menstrual period date, an early ultrasound can.
From now on, your baby is going to grow, grow, grow! The placenta is also fully developed. The cartilage skeleton is beginning to turn into hard bone. They can also swallow. Get weekly updates on your baby’s development from our expert midwives straight to your inbox. The scan happens in the hospital, and most offer a copy of the picture of your baby from your scans. You may need to pay for this, so take some money with you to your scan appointment.
They are printed on thermal paper, so don’t laminate them! At that point, you know it’s real and it’s happening. Your hospital or birth centre is likely to offer free NHS classes, in which they cover the birth, birth plans, breastfeeding and early days with your baby. Antenatal classes won’t usually start until mid- to late pregnancy but they can get booked up quickly so it’s worth signing up for them now.
It could be a midwife-led birth centre, a hospital birth centre or a home birth. The choices that you have will depend on where you live and whether you have any health complications. If you decide early on in your pregnancy where you would like to have your baby, you can change your mind later.
Estimated date of delivery
The thing is, because the date carries such meaning to us, we hang everything on it, and rightly so. We start planning, things like…. Yes, I kid you not! There are other due date calculation methods that exist that are based on science and research , but these tend not to be used. Crazy I know!
Can your pregnancy scan give the wrong due date? So like you I am technically Sept 24th now but went 10 days over on dd and fully expect to be here on 1st.
Log in Sign up. Is it safe to …? Is it true? Home Pregnancy You and your bump. How to count your pregnancy in weeks and months. In this article How many weeks pregnant am I? What if I don’t know the date of my last period or I have irregular periods? How can I be four weeks pregnant when I’m in my fifth week of pregnancy? What is a trimester?
If you were having regular periods before pregnancy, your doctor will calculate your due date based off of your last menstrual period. This goes back to the fact that in order to get pregnant, your body ovulated—or released an egg—roughly in the middle of your cycle and it was fertilized by sperm. That was the moment of conception. Is an ultrasound a more accurate way of finding out my due date?
If you are having irregular cycles before getting pregnant, an ultrasound is usually done to find out how far along you are. An ultrasound is actually the most accurate way to date a pregnancy because all fetuses grow at a consistent rate during the first trimester and early second.
This is equal to counting forward days from the date of your last period. In a study, researchers grouped ultrasound scans by
Initially, the estimated date of delivery EDD is generally calculated based on the first day of the last menstrual period LMP and may later be modified when an ultrasound US scan is performed. According to the International Society of Ultrasound in Obstetrics and Gynecology, clinical decisions should preferably be based on the EDD by US 1 , and based on first trimester ultrasound, if performed. The most frequently used formula for pregnancy dating in Sweden today is based on fetal biparietal measurements during the second trimester US scan, and this formula can be used to predict the day of delivery with a standard deviation SD of 8 days 2 , 3 , 4.
A minority of clinics perform first trimester pregnancy dating, with increasing practice during the last decade 2 , 5. Before , the combined information from measurement of the biparietal diameter and femur length were generally used 5.
If the pregnancy doesn’t show on an ultrasound scan
NCBI Bookshelf. John A. Morgan ; Danielle B.
“Then at my 12 week scan, they put me forward by 4 days.” When do you normally have a dating scan? Unless you have an early pregnancy scan most of you will.
I went in last week for my week scan and was told my baby was only measuring eight weeks approximately and had no heartbeat. I’ve had no reason to think there was anything wrong. I only had morning sickness up to then! Orla: A silent scan, which is what you’ve had, is also called a missed miscarriage. I was told it can take up to eight weeks for your placenta and sac to be naturally expelled by the body, so I guess not everybody gets a bleed.
It takes a while for your pregnancy hormones to wear off so you still feel pregnant. Amanda: I had a similar experience in January I went for my week scan and my twins had no heartbeat.