You’ve just discovered you’re pregnant. But it turns out, just because you’re a woman doesn’t mean you fully understand what’s happening inside your body during pregnancy. Pregnancy is a natural process, but it doesn’t mean you know exactly what’s going on as your belly grows and your symptoms shift.
Let’s be honest pregnancy can be stressful! While the creation, development, and birth of a child is beautiful, it can also be overwhelming. And let me tell you, it’s completely normal to feel afraid. The fact that your body was designed for reproduction doesn’t make it any easier to carry another life inside you. On top of the pregnancy itself, you may also be facing external pressures: lack of support from the child’s father, financial strain, or a shortage of resources among many other things.
So now that you’re aware of this new life growing inside you, I’m sure you’re feeling a mix of emotions: fear, joy, anxiety, and hope. While positive thinking can help, there’s something else that can bring comfort during this time: science.
Maybe science isn’t your favorite topic; maybe it bores or intimidates you, just like hearing a doctor explain a new health condition might. But I believe understanding the science behind fetal development can ease your anxieties, providing clarity and helping you connect with your baby. Learning what’s happening inside your body can help your child feel less foreign, less like an abstract concept, and more like the growing human they are.
There’s a wealth of information out there about pregnancy and birth entire books have been written on the subject! Human reproduction, especially from the woman’s perspective, is a complex and fascinating topic that can’t possibly be covered exhaustively in one blog post. So, to help break it down, we’ll be starting a Fetal Development Series, organized month by month. My hope is that learning about the development of your baby, piece by piece, will help you understand what’s happening inside your body and foster a deeper connection with your baby.
Without further delay, let’s begin Month 1 of the Fetal Development Series!
Trimester 1: Month 1
If you have a grain of rice on hand, take it out and observe it. Why? Because during the first month of pregnancy, the embryo inside you is about a quarter inch long. That’s smaller than the grain of rice you’re holding.
The first few weeks of pregnancy can be confusing. Pregnancy is considered to begin on the first day of your last menstrual period, a calculation known as the “gestational age” (Cleveland Clinic, 2022). This means that your due date is typically calculated by adding 40 weeks to the first day of your last period. So, by the time you realize you’re pregnant, you’re already at least four weeks along—often more, especially if you have fewer symptoms.
You’ve probably heard that a missed period is often the first sign of pregnancy. You might also experience mild cramping or slight spotting as the fertilized egg implants itself in your uterus (implantation) (FamilyDoctor.org, 2024). After the sperm and egg unite, they form a zygote, which divides and forms a cluster of cells that implants into the uterine lining around nine days after conception (Natalben, 2020).
For the first eight weeks, your baby is referred to as an “embryo” (Cleveland Clinic, 2022). Within the first month, several vital structures begin to develop: the amniotic sac, placenta, and umbilical cord.
Key Developments in Month 1
· Amniotic Sac: This protective sac forms around 12 days after conception (Cleveland Clinic, 2024). It surrounds the baby, placenta, and umbilical cord, and contains amniotic fluid (the fluid women refer to when their “water breaks”). Its main job is to protect the fetus from injury and infection.
· Placenta: The placenta begins to form and is crucial for the baby’s development. It supplies oxygen and nutrients while removing waste products (Gude et al., 2004).
· Umbilical Cord: Forming around week three, the umbilical cord connects the baby to the placenta. It carries oxygen-rich blood and nutrients to the baby while transporting deoxygenated blood and waste back to the placenta (Heil & Bordoni, 2023).
· Other Developments: A tube forms that will later become the baby’s brain and spinal cord. The circulatory system begins to take shape, and early features, like the beginnings of eyes and a mouth, start to develop (Cleveland Clinic, 2022).
What’s Happening in Your Body?
In addition to the changes happening inside your baby, your body is undergoing some significant transformations:
· Frequent Urination: You may feel the need to urinate more often due to increased blood flow and fluid passing through your kidneys. Later in pregnancy, the growing baby will also put pressure on your bladder (Natalben, 2020).
· Breast Changes: Tenderness and enlargement are common during the first month because of rising progesterone and estrogen levels (Natalben, 2020).
· Changes to the Vulva: You might notice darkening of the vulva or a feeling of pressure in the area due to increased blood flow (Texas Children’s, 2019).
· Vaginal Discharge: Thin, white discharge may increase (FamilyDoctor.org, 2024).
Emotional & Psychological Changes
Hormonal fluctuations can also cause mood swings, irritability, and even forgetfulness. It’s normal to feel overwhelmed, especially if this is your first pregnancy. Don’t be surprised if you feel more emotional or stressed; after all, you’re adjusting to major physical and emotional changes (Natalben, 2020).
Morning sickness is also a common symptom in the first trimester, although it can occur at any time of day. Symptoms include nausea, sensitivity to smells, and sometimes vomiting (FamilyDoctor.org, 2024). Additionally, you may experience lightheadedness, heartburn, constipation, or bloating due to your body adjusting to the pregnancy (FamilyDoctor.org, 2024).
The Pregnancy Glow and More!
You might also notice that your veins are more visible due to your heart working harder and blood volume increasing. Some women even experience the “pregnancy glow,” a natural glow from improved circulation and oil production (FamilyDoctor.org, 2024).
As for your waistline, it’s likely still early enough that you won’t see significant changes in your belly size. Most first-time mothers tend to show later because their uterine muscles haven’t been stretched by a previous pregnancy (NHS, 2023).
I hope that by reading this post, you now have a clearer understanding of what’s happening in your body during the first month of pregnancy. This knowledge can help you feel more in tune
with your baby’s development and alleviate some of the uncertainties that come with pregnancy. Remember, it’s always important to seek medical advice if anything feels unusual, even if your symptoms seem typical.
Stay tuned for Trimester 1: Month 2 coming soon!
Works Referenced:
Better Health – Start for Life. “Week-By-Week Guide to Pregnancy – Week 4.” NHS, 13 June 2023, www.nhs.uk/start-for-life/pregnancy/week-by-week-guide-to-pregnancy/1st-trimester/week-4/.
Changes During Pregnancy: What’s Normal And What’s Not? Texas Children’s, 2019, www.texaschildrens.org/content/wellness/changes-during-pregnancy-whats-normal-and-whats-not.
Cleveland Clinic. “First Trimester of Pregnancy: What to Expect.” 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, et al. “Growth and Function of the Normal Human Placenta.” PubMed, National Library of Medicine, 2004, pubmed.ncbi.nlm.nih.gov/15507270/.
Heil, Jenna, and Bruno Bordoni. “Embryology, Umbilical Cord.” StatPearls, National Library of Medicine, 2022, www.ncbi.nlm.nih.gov/books/NBK557490/.
Symptoms of the first month of pregnancy. Natalben, 2020, www.natalben.com/en/pregnancy-months/1-month-pregnant.
About the Author, Krista Ruffo
Krista Ruffo is a Volunteer Blogger with South Project. She recently graduated from the University of Central Florida 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.