Explore this week-by-week visualization of pregnancy

Fetal development, week by week

Gestation is the period of time between conception and birth when a baby grows inside the mother's womb. Changes occur constantly over the course of these 40 weeks. At week 17, for instance, the skeleton of a fetus begins changing from soft...

Examine this captivating animation 'building' a human—illustrating the roughly 40 weeks of fetal development.

What happens during the first eight weeks of pregnancy?

The first weeks of embryonic development, known as embryogenesis, are one of the most critical phases during pregnancy. This simple breakdown from the Khan Academy illustrates what we know about how the complex process unfolds.

Understand the complex, biological journey of pregnancy with this science explainer.

Explore this interactive visualization of the IVF journey as a parent or child

Touch is the first sense a fetus develops in the womb

During gestation, our sense of touch begins to develop around 8 weeks, starting with the development of sensory receptors in the face and, about a month later, in the palms and soles of the feet.

A pregnant woman's brain sheds gray matter, perhaps explaining 'baby brain.'

View an illustrative journey of sperm cells navigating toward fertilization

In this series of comic-style panels, a "fellowship" of sperm cells travels through fictionalized versions of reproductive anatomy on their way to an egg cell. Each panel includes informative commentary on each step of the adventure, with research insights provided by a reproductive biologist, a biomedical scientist, and an andrologist.

Pregnancy causes a woman's blood volume to increase by up to 50%.

Babies taste food in the womb via amniotic fluid, and it may influence future taste buds.

In the womb, a fetus may begin to hear at 18 weeks

Though little indentations form on the side of the fetus's neck at roughly nine weeks—with some formations taking place even before then—developmentally, these indentations don't become ears that allow a little one to hear until around 18 weeks.

Only about 0.0001% of sperm, on average, successfully reach the uterine cavity

We've evolved to make pregnancy a complex and difficult process. From the initial development of the blastocyst, to the energy and nutrients needed to grow a new human, our bodies are both fighting and supporting fetal development.

Each day, about 60 US pregnancies end in stillbirth

This online memorial for families who experienced the unexpected death of a fetus 20 weeks or older is the result of ProPublica reporters inviting 60 families to share their baby's name and answer some questions about their unfulfilled wishes for their children. About 21,000 babies are stillborn in the US annually. About the same number of children die in the US during their first year of life.

Explore how the placenta acts as lungs, kidneys, and more in the womb.

A step-by-step overview of the IVF process

In-vitro fertilization involves a sequence of complex steps to move from egg production to birth. This include stimulating egg production in the ovaries, egg harvesting and fertilization outside the body, embryo culturing and transfer, and methods to support in and increase the likelihood of full-term pregnancy.

Every organ in a mother's body changes during pregnancy as her body produces hormones that relax muscles, allowing for the needed expansion.

Data visualizations showing population growth around the world

This page presents data, charts, and analysis on changes in population growth around the world. Over the last few centuries, the human population has gone through an extraordinary change. In 1800, there were 1 billion people; today, there are more...

The latest data on US motherhood

Here’s a snapshot of what motherhood looks like in the U.S. today, drawn from government data and Pew Research Center surveys. The list includes seven headline statistics with visual graphs, including the average age of a mother's first childbirth...

Heightened sense of smell during pregnancy is not yet well understood

Boosted smell powers and strong reactions to them are often reported beginning around the six-week mark of pregnancy. Researchers say hormonal changes likely play a role, but the change remains poorly understood.

A baby's due date is calculated from the first day of the last menstrual period—not when sexual intercourse occurred.

Watch a salamander grow from fertilization to hatching

New microscopy techniques have allowed scientists to image the development of animal embryos with unprecedented detail. This six-minute time-lapse reveals the development of a salamander from initial fertilization to hatching from an egg.

The human body in 3D

Zygote Body is a free human anatomy tool that allows users to explore the intricacies of the human body in stunning detail. With the click of a mouse, users can isolate by body system or view anatomical structures from any angle. Check out this...

The World Bank’s population data bank

This website by the World Bank provides visualizations for demographic data from around the world. Specific demographic data, such as total population, can be viewed through maps, charts, and graphs. Results can be filtered by sex, country, or year....

Track the changes in US immigration law throughout history

This interactive timeline tracks the development of US immigration law, overlaid with time-series data on percentages of the foreign-born population. Explore how each major policy development correlated with immigration levels, revealing the relationship between legislation and demographic change.

From Ozempic to Wegovy, see the $58B weight loss drug market visualized in one chart.

Explore the rise (and fall) of baby names over time

Baby names popularity and trends in the acclaimed interactive graph of baby name popularity. Watch as baby name trends rise and fall over time.

Visualizing decades of stock market performance

Stock markets and the indexes that track their biggest companies tend to ebb and flow, with long growth periods punctuated by shorter recessions. Track the 60-year history of one of the most common stock market indexes, the S&P 500, with this data visualization. The chart highlights the long-term durability of markets despite appearance of short-term volatility.

Gestational diabetes occurs when the body can't produce insulin during pregnancy

Globally, pregnant people are increasingly at risk to develop gestational diabetes due to rising maternal ages and obesity rates. The condition is associated with heavier fetal weight, congenital abnormalities, and perinatal mortality, which includes stillbirths and deaths of babies younger than 7 days old.

Explore US public health data

This resource tracks key US health metrics, including mortality causes, child survival rates, and life expectancy comparisons, to inform future health improvements, with regularly updated global estimates.

An interactive look at your own life through demographics

This interactive site allows you to understand the journey of your life in numbers and dates. World Data Lab asks users to enter their date of birth, country of birth, and sex at birth. The site then provides an interactive page tailored to your...

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

Artificial wombs and preterm births: an overview

Scientists are working to create artificial wombs that would help preterm babies survive their early entry into the world. But how much help could this technology provide, and how much of a problem are preterm births? This article details some of...

Modern pregnancy tests detect a specific hormone in a woman's urine or blood.

Visualizing obesity rates across the US

Nearly 70% of adults in the US are either overweight or obese, rates that have tripled over the last 60 years. Severe cases have risen tenfold during this period. Factors like location, income level, and demographics contribute to various obesity levels across the US. Visualize the statistics with this article and chart series.

A gallery of medical illustrations from NIH

The National Institutes of Health provides educational materials for broad use. The institute hosts a Flickr account with many different image galleries, including this one (with over 70 images to date) that illustrate and annotate curious phenomena, from the life cycles of a malaria parasite to the comparison of male and female bladders. Explore the gallery here.

Read the 1963 study testing out an ancient Egyptian pregnancy urine test.

How stress affects every organ in the body

If you are a visual learner, this resource is for you. Not only does this article from the World Economic Forum outline the causes of modern stress along with helpful strategies, but they have created an approachable infographic to show exactly how stress manifests throughout our different bodily systems. Pair this visual guide with our other resources to gain a deep knowledge of stress and the human body.

See the progress of the war in this interactive, visual timeline

Follow the progress Russian/Ukrainian War through this interactive map. Watch as events develop, get a daily overview of movements, and switch back and forth between different dates and time periods during the conflict. Results will change in real time and depending on all available information about troop movements and more.

The science and ethics of artificial wombs

Artificial wombs may be able to help preterm babies survive their early entry into the world and possibly curb the long-term adverse health effects associated with such premature birth. This article dives into the current ethics and science behind artificial wombs and ectogenesis, which is when a fetus develops in artificial conditions.

Pregnancy makes someone more attractive to the mosquito species that transmits malaria.

Your brain appears to age in five distinct stages, with the pattern of connections inside your brain shifting, on average, around ages 9, 32, 66, and 83.

What are the phases of migraine?

Migraine attacks don't happen all at once. This interactive walks users through the phases of migraine. Scroll through this visual guide to migraine phases to learn more about migraine, related symptoms, and brain activity.

A visual database of pollens

Pollen is a powdery substance made up of small grains involved in the fertilization process of plants. There are thousands of types of pollens across the world, and you can see real images of them in this visual database.

Your feet can expand—permanently—due to pregnancy.

Follow an IVF procedure from lab to transplant

What happens once eggs are harvested from an ovary? How does an embryo form within a petri dish? This detailed video offers a glimpse of the transformations eggs experience as women age, and how sperm are injected into eggs in some forms of IVF treatment.

The ancient Egyptians developed the first pregnancy test—and scientists tested it in the 1960s and discovered it was accurate about 70% of the time.

Chagas disease can be transmitted to a fetus during pregnancy

Researchers estimate that 63 to 315 cases of congenital Chagas disease occur annually in the US. Roughly 20 to 30 percent of all Chagas disease cases will progress to cardiac or gastrointestinal disease.

See the polio cases that occur worldwide each year by region

Worldwide, the number of cases of polio reported each year from 1980 to 2024 has declined. This graphic depicts regional trends and declines by year.

Calculate your chance of success for IVF treatments

The efficacy of in vitro fertilization procedures varies widely based on age, health history, genetics, and more. This CDC calculator provides an estimate of success rates based on your personal information, relying on thousands of reported outcomes across the US.

Visualizing the world's population centers

What does population density look like on a global scale? These detailed 3D renders illustrate our biggest urban areas and highlight population trends.