Your baby has now reached the size of coriander seed and an early ultrasound scan may show his heartbeat, while you might experience some early pregnancy symptoms such as cramps, nausea and food aversions.
5 Weeks Pregnant – Fetus
The embryo now measures about 0.07 inch/ 2mm, the size of coriander seed, and weighs about 0.01 oz / 0.2 g. The yolk sac still functions, supplying your baby with oxygen and blood, but the placenta, although still primitive, and the umbilical cord, have already formed and will soon take over the task. The embryo now contains three layers of cells: the outer layer (ectoderm), the middle layer (mesoderm) and the innermost layer (endoderm) and the major organs are beginning to develop. During the fifth week of pregnancy, the embryo’s heart and circulatory system are forming in the mesoderm and his heart is dividing into chambers and will already begin functioning! A primitive neural tube is starting to develop in the top layer – the beginning of your baby’s brain, spinal cord, backbone, and nerves. During this week, nipples are beginning to form where your baby’s chest will be.
5 Weeks Pregnant – Symptoms
By the fifth week of pregnancy, the pregnancy hormone hCG levels are high enough for the home pregnancy test to detect your pregnancy. If you haven’t taken a test until now, this is the time to do it!
Are you feeling emotional? Experiencing weird cramps in the lower abdomen and nausea? Coming home from work so tired you fall asleep once your head touches the pillow? Finding yourself craving the strangest foods but shrinking from foods you used to love? Can’t stand anything or anyone touching your nipples that became ultrasensitive overnight? That’s the way your body prepares itself for the next eight months: it produces high levels of the hormones estrogen and progesterone, that will be responsible for the major changes in your body during pregnancy:
- Progesterone: Prevents the immune system from rejecting the fetus (due to his foreign DNA). It also keeps the muscles of the uterus relaxed to prevent them from contracting too early. Unfortunately, progesterone also relaxes blood vessels in your body, causing low blood pressure (which may make you feel dizzy), constipation, gas, heartburn, reflux, nausea and last but not the least, unwanted hair growth.
- Estrogen: Plays a central role in preventing miscarriage and triggers the development of several organs and bodily systems of the growing embryo, mainly the development of the adrenal gland. Estrogen is also responsible for a few well-known pregnancy symptoms such as increased appetite, morning sickness, changes in your skin pigment and spider veins. Too bad.
5 Weeks Pregnant – Questions
If you received a positive result on your home pregnancy test, you may be impatient to actually see how your baby looks at this point. Between 5 and 6 weeks pregnant, a vaginal ultrasound test can detect the fetal pole and determine whether you’re carrying one baby or more.
1. Why have an Ultrasound at 5 Weeks Pregnant?
The fetal pole is the term used to describe the earliest image of the developing embryo, that will appear like a tiny curved shape on the margin of the yolk sac. In this period of time, the ultrasound may also detect your baby’s heartbeat, that will sound like a quick flutter. A visible fetal pole will allow your caregiver to take the first crown to rump measurements (CRL) of your baby (hooray! You will finally know your baby’s size! He may be apple-seed-sized now, but it’s still exciting..) and calculate a more accurate due date. It will also allow you to see if you’re carrying twins and will detect the placenta positioning, possible abnormalities or an ectopic pregnancy.
2. What if the Ultrasound Showed no Fetal Pole?
If the vaginal ultrasound shows no fetal pole or fetal heartbeat, don’t panic. If you had irregular cycles or gave your caregiver an incorrect date of your last menstrual period date, it may mean that your pregnancy dating is inaccurate, so it may be too early at this point to see the embryo. In some cases, the fetal pole may not be seen until you’re 9 weeks pregnant. If there’s a possibility that the pregnancy dating is inaccurate, you will be asked to come back for another ultrasound scan in 3-7 days.
3. When does no Fetal Pole mean I had a Miscarriage?
Unfortunately, no fetal pole on the ultrasound scan can also be a sign of a miscarriage. In this case, the ultrasound shows an empty gestational sac (blighted ovum). A blighted ovum can sometimes stay visible for a few weeks after the scan and the gestational sac may keep growing despite the lack of an embryo before you start experiencing any miscarriage symptoms. If your first ultrasound scan shows no fetal pole with a gestational sac larger than 16mm, it is enough to diagnose miscarriage. Otherwise, you will be asked to repeat the scan. Miscarriage can be conclusively diagnosed if the second ultrasound scan still shows no fetal pole.
4. What are my Odds of Carrying Twins?
Any woman can become pregnant with twins or triplets, but you’re also more likely to be carrying multiples if someone else in your family had twins, if you’re older than 35 or if you’ve undergone fertility treatments. About 3 percent of births are twin births. Twins can be either identical (monozygotic, which means that they develop from a single zygote, which splits and forms two embryos) or fraternal(dizygotic, which means that they develop from two eggs which were fertilized by two different sperm cells).