Welcome back to the Fetal Development Series! If you haven’t yet read it, I recommend going back into South Project’s blog posts to read Part I of this series, which covered weeks one to four of the first trimester. If you’ve already read it, great! Now we can move on to weeks five through eight of fetal development.
Since we’re still in the first trimester, many of the symptoms and developmental milestones of month one still apply to month two. But while you may feel the same week to week, the developmental milestones for your baby are becoming much more significant. As discussed previously, it’s important to remember that every woman is different; some may have strong symptoms while others barely have any at all. If you happen to speak to another woman who is currently pregnant or has been in the past and her experience was or is unlike yours, don’t be worried that something is “wrong” with you. Every woman is unique!
At the point that you are beginning week five of pregnancy, you may have just discovered that you’re pregnant. Perhaps your period is late. If you’re not sure, now’s an excellent time to take a pregnancy test if you haven’t already. As discussed in Fetal Development Part I, by the time you figure out you’re pregnant, you could already be about four weeks along, since “your pregnancy actually begins on the first day of your last menstrual period” (First Trimester).
Also, now’s a great time to start seeking out healthcare if you haven’t already. Getting connected to a pregnancy care provider (like an OB–GYN) in your area is important for prenatal checkups to ensure that you and the baby are doing well. Those checkups are also a great time to ask your health provider any questions you may have. Your first prenatal visit will involve a physical exam as well as other tests and screenings (The First Trimester).
Without further ado, here is part two of this fetal development series.
Trimester 1
Month 2 (Weeks 5 – 8)
Fetal Development Milestones
During weeks five to eight of pregnancy is when the big stuff starts developing. We’re talking lungs, brain, spinal cord, heart, ears, and limbs (First Trimester). Attached to those limbs are fingers and toes that are still webbed, but are starting to appear more distinct (First Trimester). This also includes all the major systems, such as the nervous, digestive, circulatory, and urinary systems (First Trimester). Your baby’s skeletal structure is also forming. Since the embryo’s heart is developing, a very early heartbeat may be confirmed during this time by some providers (First Trimester). And here’s the best part: your embryo is in constant motion—you just can’t yet feel it (First Trimester).
As we talked about last time, the amniotic sac, umbilical cord, and placenta are forming and are vital to the baby’s development and survival. By week seven the umbilical cord—the vital connection between the fetus and placenta—has fully formed and is continuing its process of transporting blood (Heil 2023). Between your fourth and eighth week “there is an increase in amniotic fluid production” (Amniotic Sac 2024). So with “the expansion of the amniotic cavity and elongation of the umbilical cord,” your baby now has “ample space for movement and growth” (Amniotic Sac 2024). The placenta is also still doing its thing, by providing “oxygen and nutrients to the fetus” as well as “removing carbon dioxide and other waste products” (Gude 2024). The placenta is still helping to protect the fetus against infections and maternal diseases and is releasing “hormones into both the maternal and fetal circulations to affect pregnancy, metabolism, fetal growth,” and other functions (Gude 2024).
During the first trimester, or weeks one to twelve, is when a child is most susceptible to damage, whether that be from alcohol, radiation, certain drugs and medicines, and a variety of toxic substances (The First Trimester). So now is the time to be extra safe and consider any medicines you take. If you routinely drink alcohol and just discovered or even suspect you may be pregnant, now is the time to cut out all drinking.
And if you’re wondering whether it’s too early to determine the gender of the baby, the answer is unfortunately yes. Hold on a little longer! While the internal genital systems will develop throughout month two, “the external genitals have not yet been differentiated, so the sex cannot yet be determined by looking at an ultrasound scan” (Herráiz). Once you do start getting ultrasound scans, they will be useful in the evaluation of fetal anatomy, measuring amniotic fluid levels, watching for fetal movement, and visualizing fetal blood flow” (Heil 2023). We’ll be talking more about determining the sex of the baby in month three.
As you may have noticed from images of embryos, the head often looks comically larger than the body. But by the end of week eight your child starts to look more like a human and less like a very small alien. This is mostly because the head–to–body ratio begins to even out and your child’s face has begun forming. Your embryo’s mouth “is developing tooth buds, which will become baby teeth,” and the “eyes, nose, mouth, and ears are becoming more distinct” (First Trimester). By the end of month two your “embryo” becomes a “fetus” and is about as large as a raspberry, or about an inch to an inch and a half in length (First Trimester).
Isn’t it amazing that even at such an early stage, your child is already developing so quickly?
Bodily Changes in Weeks Four to Eight
Since your pregnancy isn’t very far along and your embryo is still quite small, you won’t have a noticeable baby bump yet, especially if this is your first time being pregnant. It’s normal to feel very fatigued and nauseated and to start having stronger–than–usual food cravings. Remember, your body is changing rapidly to accommodate the new life inside of you. Your body makes “more estrogen during one pregnancy than it does during your entire life when you’re not pregnant,” so don’t be frightened when you don’t feel quite normal (First Trimester). You could have a metallic taste in your mouth, nausea and vomiting (better known as morning sickness, which doesn’t only happen in the morning), mood swings, stronger sense of smell, milky white vaginal discharge, thicker and shinier hair, and darkened skin on your face (or the “mask of pregnancy”) (Week 5).
Breast changes occur in preparation for breast–feeding, such as soreness, which is caused by your enlarged mammary glands (The First Trimester). Your areolas (or the pigmented circle surrounding your nipple) may enlarge and darken (The First Trimester). You may even notice veins or tiny white bumps around your nipples, which are enlarged sweat glands (The First Trimester). Since your body is making extra blood and your heart is pumping faster, these noticeable veins may not only show on your breasts but may appear on your neck, legs, belly, and arms (FamilyDoctor.org Editorial Staff). Since your blood volume increases by about 10%, these changes can also cause your genital area to take on a darkened tone (Herráiz).
Bathroom changes are likely to happen in the form of needing to pee more often since your expanding uterus is pressing on your bladder. Since your uterus is also starting to push against your rectum and colon more, you may experience constipation. Constipation can also be caused by the hormone progesterone’s slowing effect on the muscular contractions in the digestive tract (The First Trimester). Other than trouble in the bathroom, you could also be bloated, have more gas, and experience heartburn (The First Trimester).
As discussed above, you could start strongly craving food you normally like and food you normally dislike. You could even develop a strong aversion to foods you normally do like! Again, don’t let this scare you; the pregnancy palate can be quite a strange experience.
Overview of Month Two of Fetal Development
In conclusion, month two may not feel all that much different from month one, depending on your symptoms. Despite this, your baby is rapidly developing, and very soon you will be able to know the gender. You may have also been given a due date if you’ve seen an OB–GYN already. To the best of your ability, please try not to worry when any symptoms strike. Try to get as much sleep as you can and consider reading my post on a healthy pregnancy diet.
Here’s a recap of your baby’s weeks four to eight development:
- Digestive, urinary, circulatory, respiratory, and nervous systems
- Internal genital structure
- Facial structure, including ears
- Limbs, hands, and feet
- Skeleton
And here’s a recap of some symptoms you may have:
- Nausea
- Vomiting
- Sore breasts
- More noticeable veins
- Vaginal discharge
- Food cravings
- Fatigue
- Mood swings
- Constipation
- Bloating
- Heartburn
- Frequent urination
- Darkening of your areolas, vulva, and face
- Stronger sense of smell
- Thicker and shinier hair
Finally, here are some key takeaways:
- Good time to confirm pregnancy through testing
- Get connected with pregnancy provider
- Gender reveal coming soon!
- Stay strong through symptoms
- Consider altering diet
If you enjoyed this post, stick around for further posts on fetal development and maintaining a good pregnancy diet.
See you next time!
Works Cited
Amniotic Sac. Cleveland Clinic. 11 Sept. 2024, my.clevelandclinic.org/health/body/amniotic-sac.
Cleveland Clinic. “First Trimester.” Cleveland Clinic, 22 Aug. 2022, my.clevelandclinic.org/health/articles/9699-first-trimester.
FamilyDoctor.org Editorial Staff. “Changes in Your Body during Pregnancy: First Trimester.” FamilyDoctor.org, Aug. 2024, familydoctor.org/changes-in-your-body-during-pregnancy-first-trimester/.
Gude, Neil M., et al. “Growth and Function of the Normal Human Placenta.” Thrombosis Research, PubMed, 2004, pubmed.ncbi.nlm.nih.gov/15507270/.
Heil, Jenna R., and Bruno Bordoni. “Embryology, Umbilical Cord.” StatPearls, NIH, 17 Apr. 2023, www.ncbi.nlm.nih.gov/books/NBK557490/.
Herráiz, Miguel Ángel. “Symptoms of the Second Month of Pregnancy.” Natalben, www.natalben.com/en/pregnancy-months/2-months-pregnant.
The First Trimester. “Wellness and Prevention.” John Hopkins Medicine, 2019, www.hopkinsmedicine.org/health/wellness-and-prevention/the-first-trimester.
Week 5. “Start for Life.” Better Health, NHS, 13 June 2023, www.nhs.uk/start-for-life/pregnancy/week-by-week-guide-to-pregnancy/1st-trimester/week-5/.
“About the Author, Krista Ruffo
Krista Ruffo is a Volunteer Blogger with South Project. She’s a UCF grad with a bachelor’s degree in English and a Certificate in Editing and Publishing. A passionate writer and reader, Krista aspires to work in children’s book publishing in the future. In her free time, she enjoys writing poems, taking photos, and gardening. Krista lives in Orlando, FL, with her four beloved cats.”