Assisted reproductive technology in the context of "First trimester"

Pregnancy is the time during which one or more offspring gestates inside a woman's uterus. A multiple pregnancy involves more than one offspring, such as with twins.

Conception usually occurs following vaginal intercourse, but can also occur through assisted reproductive technology procedures. A pregnancy may end in a live birth, a miscarriage, an induced abortion, or a stillbirth. Childbirth typically occurs around 40 weeks from the start of the last menstrual period (LMP), a span known as the gestational age; this is just over nine months. Counting by fertilization age, the length is about 38 weeks. Implantation occurs on average 8–9 days after fertilization. An embryo is the term for the developing offspring during the first seven weeks following implantation (i.e. ten weeks' gestational age), after which the term fetus is used until the birth of a baby.

In biology, infertility is the inability of a male and female organism to reproduce. It is usually not the natural state of a healthy organism that has reached sexual maturity, so children who have not undergone puberty, which is the body's start of reproductive capacity, are excluded. It is also a normal state in women after menopause.

In humans, infertility is defined as the inability to become pregnant after at least one year of unprotected and regular sexual intercourse involving a male and female partner. There are many causes of infertility, including some that medical intervention can treat. Estimates from 1997 suggest that worldwide about five percent of all heterosexual couples have an unresolved problem with infertility. That figure has been on the rise, with the World Health Organization (WHO) reporting in 2023 that about 17.5% of people experience infertility during their lifetime, while prevalence at a given time point is 12.6%. Many more couples, however, experience involuntary childlessness for at least one year, with estimates ranging from 12% to 28%.

Stillbirth is typically defined as the death of a fetus at or after 20 or 28 weeks of pregnancy, depending on the source. It results in a baby born without signs of life. A stillbirth can often result in the feeling of guilt or grief in the mother. The term is in contrast to miscarriage, which is an early pregnancy loss, and sudden infant death syndrome, where the baby dies a short time after being born alive.

Often the cause is unknown. Causes may include pregnancy complications such as pre-eclampsia and birth complications, problems with the placenta or umbilical cord, birth defects, infections such as malaria and syphilis, and poor health in the mother. Risk factors include a mother's age over 35, smoking, drug use, use of assisted reproductive technology, and first pregnancy. Stillbirth may be suspected when no fetal movement is felt. Confirmation is by ultrasound.

Artificial insemination is the deliberate introduction of sperm into a female's cervix or uterine cavity for the purpose of achieving a pregnancy through in vivo fertilization by means other than sexual intercourse. It is a fertility treatment for humans, and is a common practice in animal breeding, including cattle (see frozen bovine semen) and pigs.

Artificial insemination may employ assisted reproductive technology, sperm donation and animal husbandry techniques. Artificial insemination techniques available include intracervical insemination (ICI) and intrauterine insemination (IUI). Where gametes from a third party are used, the procedure may be known as 'assisted insemination'.

Ectopic pregnancy is a complication of pregnancy in which the embryo attaches outside the uterus. This complication has also been referred to as an extrauterine pregnancy (a.k.a. EUP). Signs and symptoms classically include abdominal pain and vaginal bleeding, but fewer than 50 percent of affected women have both of these symptoms. The pain may be described as sharp, dull, or crampy. Pain may also spread to the shoulder if bleeding into the abdomen has occurred. Severe bleeding may result in a fast heart rate, fainting, or shock. With very rare exceptions, the fetus is unable to survive.

Overall, ectopic pregnancies annually affect less than 2% of pregnancies worldwide. Risk factors for ectopic pregnancy include pelvic inflammatory disease, often due to chlamydia infection; tobacco smoking; endometriosis; prior tubal surgery; a history of infertility; and the use of assisted reproductive technology. Those who have previously had an ectopic pregnancy are at much higher risk of having another one. Most ectopic pregnancies (90%) occur in the fallopian tube, which are known as tubal pregnancies, but implantation can also occur on the cervix, ovaries, caesarean scar, or within the abdomen. Detection of ectopic pregnancy is typically by blood tests for human chorionic gonadotropin (hCG) and ultrasound. This may require testing on more than one occasion. Other causes of similar symptoms include: miscarriage, ovarian torsion, and acute appendicitis.