A multiple birth is the culmination of one multiple pregnancy, wherein the mother gives birth to two or more babies. A term most applicable to vertebrate species, multiple births occur in most kinds of mammals, with varying frequencies. Such births are often named according to the number of offspring, as in twins and triplets. In non-humans, the whole group may also be referred to as a litter, and multiple births may be more common than single births. Multiple births in humans are the exception and can be exceptionally rare in the largest mammals.
Amniocentesis is a medical procedure used primarily in the prenatal diagnosis of genetic conditions. It has other uses such as in the assessment of infection and fetal lung maturity. Prenatal diagnostic testing, which includes amniocentesis, is necessary to conclusively diagnose the majority of genetic disorders, with amniocentesis being the gold-standard procedure after 15 weeks' gestation.
Obstetric ultrasonography, or prenatal ultrasound, is the use of medical ultrasonography in pregnancy, in which sound waves are used to create real-time visual images of the developing embryo or fetus in the uterus (womb). The procedure is a standard part of prenatal care in many countries, as it can provide a variety of information about the health of the mother, the timing and progress of the pregnancy, and the health and development of the embryo or fetus.
External cephalic version (ECV) is a process by which a breech baby can sometimes be turned from buttocks or foot first to head first. It is a manual procedure that is recommended by national guidelines for breech presentation of a pregnancy with a single baby, in order to enable vaginal delivery. It is usually performed late in pregnancy, that is, after 36 gestational weeks, preferably 37 weeks, and can even be performed in the early stages of childbirth.
Twin-to-twin transfusion syndrome (TTTS), also known as feto-fetal transfusion syndrome (FFTS), twin oligohydramnios-polyhydramnios sequence (TOPS) and stuck twin syndrome, is a complication of monochorionic multiple pregnancies in which there is disproportionate blood supply between the fetuses. This leads to unequal levels of amniotic fluid between each fetus and usually leads to death of the undersupplied twin and, without treatment, usually death or a range of birth defects or disabilities for a surviving twin, such as underdeveloped, damaged or missing limbs, digits or organs, especially cerebral palsy.
A hysterotomy is an incision made in the uterus. This surgical incision is used in several medical procedures, including during termination of pregnancy in the second trimester and delivering the fetus during caesarean section. It is also used to gain access and perform surgery on a fetus during pregnancy to correct birth defects, and it is an option to achieve resuscitation if cardiac arrest occurs during pregnancy and it is necessary to remove the fetus from the uterus.
Placental abruption is when the placenta separates early from the uterus, in other words separates before childbirth. It occurs most commonly around 25 weeks of pregnancy. Symptoms may include vaginal bleeding, lower abdominal pain, and dangerously low blood pressure. Complications for the mother can include disseminated intravascular coagulopathy and kidney failure. Complications for the baby can include fetal distress, low birthweight, preterm delivery, and stillbirth.
Fetoscopy is an endoscopic procedure during pregnancy to allow surgical access to the fetus, the amniotic cavity, the umbilical cord, and the fetal side of the placenta. A small (3–4 mm) incision is made in the abdomen, and an endoscope is inserted through the abdominal wall and uterus into the amniotic cavity. Fetoscopy allows for medical interventions such as a biopsy or a laser occlusion of abnormal blood vessels or the treatment of spina bifida.
Bloody show or show is the passage of a small amount of blood or blood-tinged mucus through the vagina near the end of pregnancy. It is caused by thinning and dilation of the cervix, leading to detachment of the cervical mucus plug that seals the cervix during pregnancy and tearing of small cervical blood vessels, and is one of the signs that labor may be imminent. The bloody show may be expelled from the vagina in pieces or altogether and often appears as a jelly-like piece of mucus stained with blood. Although the bloody show may be alarming at first, it is not a concern of patient health after 37 weeks gestation.
Pregnancy is the time during which one or more offspring develops (gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins.
Prelabor rupture of membranes (PROM), previously known as premature rupture of membranes, is breakage of the amniotic sac before the onset of labour. Women usually experience a painless gush or a steady leakage of fluid from the vagina. Complications in the baby may include premature birth, cord compression, and infection. Complications in the mother may include placental abruption and postpartum endometritis.
Complications of pregnancy are health problems that are related to, or arise during pregnancy. Complications that occur primarily during childbirth are termed obstetric labor complications, and problems that occur primarily after childbirth are termed puerperal disorders. While some complications improve or are fully resolved after pregnancy, some may lead to lasting effects, morbidity, or in the most severe cases, maternal or fetal mortality.
Placenta accreta occurs when all or part of the placenta attaches abnormally to the myometrium. Three grades of abnormal placental attachment are defined according to the depth of attachment and invasion into the muscular layers of the uterus:
- Accreta – chorionic villi attached to the myometrium, rather than being restricted within the decidua basalis.
- Increta – chorionic villi invaded into the myometrium.
- Percreta – chorionic villi invaded through the perimetrium.
Fetal surgery, also known as antenatal surgery or prenatal surgery, is a growing branch of maternal-fetal medicine that covers any of a broad range of surgical techniques that are used to treat congenital abnormalities in fetuses who are still in the pregnant uterus. There are three main types: open fetal surgery, which involves completely opening the uterus to operate on the fetus; minimally invasive fetoscopic surgery, which uses small incisions and is guided by fetoscopy and sonography; and percutaneous fetal therapy, which involves placing a catheter under continuous ultrasound guidance.
Maternal–fetal medicine (MFM), also known as perinatology, is a branch of medicine that focuses on managing health concerns of the mother and fetus prior to, during, and shortly after pregnancy.
Velamentous cord insertion is a complication of pregnancy where the umbilical cord is inserted in the fetal membranes. It is a major cause of antepartum hemorrhage that leads to loss of fetal blood and associated with high perinatal mortality. In normal pregnancies, the umbilical cord inserts into the middle of the placental mass and is completely encased by the amniotic sac. The vessels are hence normally protected by Wharton's jelly, which prevents rupture during pregnancy and labor. In velamentous cord insertion, the vessels of the umbilical cord are improperly inserted in the chorioamniotic membrane, and hence the vessels traverse between the amnion and the chorion towards the placenta. Without Wharton's jelly protecting the vessels, the exposed vessels are susceptible to compression and rupture.
Monoamniotic twins are identical or semi-identical twins that share the same amniotic sac within their mother's uterus. Monoamniotic twins are always monochorionic and are usually termed Monoamniotic-Monochorionic twins. They share the placenta, but have two separate umbilical cords. Monoamniotic twins develop when an embryo does not split until after formation of the amniotic sac, at about 9–13 days after fertilization. Monoamniotic triplets or other monoamniotic multiples are possible, but extremely rare. Other obscure possibilities include multiples sets where monoamniotic twins are part of a larger gestation such as triplets, quadruplets, or more.
Circumvallate placenta is a rare condition affecting about 1-2% of pregnancies, in which the amnion and chorion fetal membranes essentially "double back" on the fetal side around the edges of the placenta. After delivery, a circumvallate placenta has a thick ring of membranes on its fetal surface. Circumvallate placenta is a placental morphological abnormality associated with increased fetal morbidity and mortality due to the restricted availability of nutrients and oxygen to the developing fetus.
Foeticide, or feticide, is the act of killing a fetus, or causing a miscarriage. Definitions differ between legal and medical applications, whereas in law, feticide frequently refers to a criminal offense, in medicine the term generally refers to a part of an abortion procedure in which a provider intentionally induces fetal demise to avoid the chance of an unintended live birth, or as a standalone procedure in the case of selective reduction.
A high-risk pregnancy is a pregnancy where the mother or the fetus has an increased risk of adverse outcomes compared to uncomplicated pregnancies. No concrete guidelines currently exist for distinguishing “high-risk” pregnancies from “low-risk” pregnancies; however, there are certain studied conditions that have been shown to put the mother or fetus at a higher risk of poor outcomes. These conditions can be classified into three main categories: health problems in the mother that occur before she becomes pregnant, health problems in the mother that occur during pregnancy, and certain health conditions with the fetus.
