Welcome to Your Pregnancy, Week by Week

Welcome to Parents’ week-by-week guide to pregnancy. First—congratulations. Pregnancy can be an exciting time. It can also be nerve-wracking and overwhelming. Is this symptom normal? What can I expect at an appointment? Should I go with a midwife or OB-GYN, and do I need a doula? 

The answers to some of these questions, like the decision to hire a doula to help you with pregnancy, labor, delivery, and postpartum, is highly personal. Others, like why you’re experiencing mood swings, is often a bit more straightforward (Spoiler alert: Hormones play a huge role in many common pregnancy symptoms).

For the next 40 weeks (give or take), your body will undergo major transformations, and you have a lot to think about. 

We’re here to help.

At Parents, we’ve put together week-by-week guides to help all pregnant people live in the present and plan for the future. Each week, we’ll discuss:

• How much the embryo or fetus has grown this week (with size comparisons)
• Milestones and development your little one-to-be is approaching
• What to expect at upcoming appointments
• Answers to common questions
• Ways to plan and things to consider ahead of delivery day

Pregnancy typically involves three trimesters, and this guide covers all of them.

First Trimester

Week 1 to 13

This trimester starts before conception. Week 1 is your period, and you’ll typically ovulate the second week. Most at-home tests will pick up a pregnancy around week four or five, though some may happen sooner. If you’re undergoing assisted reproduction, such as IVF, you may find out sooner as you’ll be monitored more closely. 

Symptoms

Regardless of how you’ve conceived, first-trimester symptoms can range from pesky to downright exhausting. Common ones include:

• Morning sickness, with or without vomiting
• Fatigue
• Food aversions
• Breast tenderness
• Heartburn
• Mood swings

Tests

You’ll likely have doctor’s appointments about once per month, though people who conceived via IVF will likely have more. During those appointments, health care providers may perform or order testing to check on you and the fetus. These tests may include:

• A blood test to confirm the pregnancy (there may also be serial blood testing to support viability)
• Dating ultrasound
• A nuchal translucency blood test and ultrasound to check for genetic conditions, like Down syndrome

Milestones

It’ll be a while before your little one takes their first steps and says “mama” or “dada” for the first time. But they’re already achieving big things. In the first trimester, milestones for you and the little one include:

• Conceiving 
• Learning you’re pregnant
• Organ development—all will have started by the end of the first trimester

Second Trimester

Weeks 14 to 27

Often known as the “honeymoon phase” of pregnancy, symptoms like nausea and fatige begin to subside for many (but not everyone) in the second trimester. You also may “pop” or begin to show. 

Symptoms

Though many people report having more energy and fewer symptoms in the second trimester, everyone is different. And as your baby-to-be grows and you progress in your pregnancy, you may notice new symptoms arising like:

• Darkening areola
• Skin discoloration
• Linea nigra
• Lower back pain
• Carpel tunnel syndrome

Tests

Prenatal appointments will continue to be once monthly, unless your provider advises otherwise. But those appointments are important—they’ll allow for additional information and testing to ensure you and the fetus are progressing safely. Some tests you’ll undergo include:

• Quadruple screen test to check for potential additional genetic issues like spina bifida
• Anatomy ultrasound scan
• Gestational diabetes screening/diagnostic testing

Milestones

Your future baby is growing and developing at a rapid pace during the second trimester. Milestones include:

• Gaining more than 2 pounds from about an ounce to 2.25 pounds
• Growing more than 10 inches
• Liver, brain, and hearing development
• Arms and legs grow to be proportionate with the rest of their body
• Feeling the fetus move
• Learning the sex (optional) 
• Fetal viability (typically around 24 weeks)

Third Trimester

Weeks 28 to 42

The home stretch can feel like a slog at times. You’re excited to meet your future baby, but you know that usually the longer the little one stays in the womb, the better. Your due date is 40 weeks, but your baby could come before or after. Your provider will keep an eye on how the pregnancy is progressing and inform you of your options should you have complications, such as preeclampsia, or go past your estimated due date. In the meantime, you’ll continue to prepare for your little one—and they’ll continue to grow and develop to prepare for life on the outside.

Symptoms

As your fetus grows, old symptoms may return and new ones may arise. Common third-trimester symptoms include:

• Nausea
• Frequent urination
• Urinary incontinence 
• Indigestion 
• Swollen legs and ankles
• Braxton Hicks contractions
• Insomnia
• Varicose veins 
• Back pain
• Pelvic pain

Tests

To ensure you and your fetus are healthy and safe, your provider may run tests, including:

• Biophysical profile (an ultrasound to check amniotic fluid levels and fetal well-being)
• Group B strep test
• Non-stress test (this is more common for high-risk pregnancies with complications like gestational diabetes, elevated blood pressure, or multiple gestation)

Milestones

You’re in the home stretch, but the little one has some more developing to do to help make for a smoother transition to life on the outside. Milestones for them may include:

• Lung maturation
• Opening of their eyes
• Move into the head-down position to prepare for labor
• Finger nail growth
• A baby shower or sprinkle

Fourth Trimester

So much anticipation revolves around labor and delivery. But life after birth can bring about a range of emotions. Though you are tasked with caring for a tiny human, it’s essential to care for yourself, too. People may be eager to hold the baby—you deserve to be held, too.

Postpartum depression can occur within a year of giving birth. Symptoms include fatigue, constantly feeling overwhelmed, and persistent unexplained crying. Help is available in the form of therapy, groups, and medication. There’s no shame in reaching out for anything you may be feeling after giving birth—you and your baby will be better for it.