Pregnancy

Pregnancy is the time when one or more offspring grow inside a woman’s uterus. It usually begins after conception, which happens when a sperm cell joins with an egg cell. This can occur following vaginal intercourse or through special medical procedures called assisted reproductive technology. A pregnancy can end in different ways, such as a live birth, a miscarriage, an induced abortion, or a stillbirth.

Pregnancy lasts about 40 weeks from the start of the last menstrual period, which is just over nine months. During this time, the developing baby goes through many changes. In the early weeks, it is called an embryo, and later it is known as a fetus. Common early signs of pregnancy include missed periods, tender breasts, and morning sickness.

The period of pregnancy is divided into three parts called trimesters, each lasting about three months. The first trimester is when the fertilized egg attaches to the uterus and begins to grow. The second trimester is when the mother might start feeling the baby move. By the third trimester, the baby is almost ready to be born. Prenatal care, such as regular check-ups and healthy nutrition, is very important to keep both the mother and the baby safe and healthy.

Terminology

Associated terms for pregnancy are gravid and parous. Gravida refers to the number of times a female has been pregnant. The term parity is used for the number of times that a female carries a pregnancy to a viable stage. Twins and other multiple births are counted as one pregnancy and birth.

A woman who has never been pregnant is referred to as a nulligravida. A woman who is pregnant for the first time is referred to as a primigravida, and a woman in subsequent pregnancies as a multigravida or as multiparous. A pregnancy is considered term at 37 weeks of gestation. It is preterm if less than 37 weeks and post-term at or beyond 42 weeks of gestation.

Demographics

About 213 million pregnancies happened in 2012, with most occurring in the developing world. Pregnancy rates and the ages at which they occur vary by country and region, influenced by cultural, social, and religious norms, access to contraception, and education levels. The total fertility rate (TFR) was highest in Niger and lowest in South Korea.

Teenage pregnancy refers to pregnancies among adolescents aged 10 to 19 years. These pregnancies carry higher health risks for both the mother and the baby, including preterm birth and low birth weight. Teenage mothers and their children often face social challenges, such as stigma, lower education levels, and poverty. Many teenage girls may also be in difficult relationships when they become pregnant.

Diagnosis

Pregnancy usually starts after penile-vaginal sex, but it can also happen through assisted reproductive technology. We can find out about pregnancy by looking at a woman's symptoms or by using pregnancy tests.

Pregnant women often notice changes such as breast tenderness, morning sickness, and missed periods. Other signs include special markings on the skin, such as a dark line on the belly called the linea nigra, and changes in the cervix. Some women also feel tired, have headaches, or notice changes in their appetite. Pregnancy tests look for a special hormone made by the placenta, which helps confirm that a woman is pregnant. Ultrasound imaging can also help check on the baby's health and development.

Timeline

The chronology of pregnancy is usually measured as gestatal age, starting from the beginning of a woman's last menstrual period. This means a woman is considered pregnant two weeks before conception happens. Sometimes, doctors use the age of the embryo since conception instead.

Pregnancy is divided into three trimesters, each lasting about three months. The first trimester is the first 12 weeks, the second trimester is weeks 13 to 27, and the third trimester continues until childbirth.

To estimate when a baby might be born, doctors add 40 weeks (about 280 days) to the start of the pregnancy. This is a general guide, and many babies are born a little earlier or later.

Physiology

Pregnancy happens when a woman’s egg joins with a man’s sperm. This usually occurs after sexual intercourse, but can also happen through special medical help like in vitro fertilisation. If a woman has a working female reproductive system, she can become pregnant.

After the egg and sperm join, they form a tiny ball of cells called a zygote. This ball of cells moves to the uterus where it attaches and starts to grow. Over time, it develops into a baby. Pregnancy usually lasts about nine months, after which the baby is born during childbirth. Most births happen naturally, but sometimes a cesarean section is needed if there are problems.

Management

Main articles: Prenatal care and pre-conception counseling

Prenatal care is important for keeping both the mother and the baby healthy during pregnancy. It includes regular check-ups with a healthcare provider to monitor the health of both the mother and the growing baby. These visits help spot any problems early and manage them. During these visits, the healthcare provider will check the mother’s blood pressure, weight, and the baby’s heartbeat. They will also discuss any symptoms the mother might be experiencing and provide guidance on what to expect.

Good nutrition is also vital during pregnancy. Eating a balanced diet with plenty of fruits, vegetables, whole grains, and proteins helps support the baby’s growth. Certain nutrients, like folic acid, are especially important to prevent birth defects. Healthcare providers often give advice on the best foods to eat and any supplements that might be needed. Staying at a healthy weight during pregnancy is important, and healthcare providers can offer guidance on how much weight to gain based on the mother’s starting weight.

Complications and diseases

Main article: Complications of pregnancy

See also: High-risk pregnancy

Each year, many women experience health problems because of pregnancy. In 2016, pregnancy complications led to over 200,000 deaths worldwide, though this number has been decreasing over time. Some common causes include bleeding, infections, high blood pressure during pregnancy, and difficulties during labor.

Pregnancy can also bring about other health issues, such as anemia, severe nausea and vomiting, and skin changes. Women may also face increased risks from existing conditions like diabetes or thyroid disorders. Support is important for both mothers and fathers when facing these challenges.

Birth control and abortion

Main article: Birth control

Main article: Abortion

Main article: Assisted reproductive technology

Family planning and the use of contraception, along with good sex education, help people choose when they want to have babies. This is part of important global goals set by the United Nations.

Modern medicine offers special methods to help couples have children when they have difficulty doing so naturally. These include medicines to help with fertility, procedures to place sperm, and techniques where embryos are created outside the body before being placed in the uterus.

Society and culture

Further information: Reproductive rights and Reproductive justice

Many countries have laws to protect pregnant women and their babies. These laws might stop pregnant women from doing hard work, like lifting heavy things or working late at night. They might also give women time off from work when they’re expecting a baby. For example, in Norway, mothers can take about eight months off with full pay, while in the United States, paid leave depends on the state.

In some places, there are differences in how people are treated during pregnancy based on their race or background. For example, in the United States, babies of some racial groups face higher risks during birth than others. This is an important health issue that people are working to improve.

Transgender people

Main article: Transgender pregnancy

Being pregnant can be a complex experience for transgender people. While the medical care during pregnancy is generally the same, transgender individuals may face extra challenges, such as discrimination or a lack of understanding from healthcare providers. This can make it harder for them to get the support they need.

Culture

In many cultures, pregnant women are treated with special care and respect. However, they may also feel pressure to meet certain expectations, such as having a son. Pregnancy often comes with traditions and customs, like baby showers, which are celebrations for the upcoming arrival of a new baby. These traditions can have roots in religion, medicine, or long-standing cultural practices.

Arts

Pregnancy has been a subject in art and literature for centuries. Ancient cultures made figures that may show pregnant women, and many artworks through history have depicted pregnancy, especially in religious contexts. Famous stories and books, such as Tess of the d'Urbervilles by Thomas Hardy, also explore the experiences of pregnant women.