This procedure involves removal of amniotic fluid periodically throughout the pregnancy under the assumption that the extra fluid in the recipient twin can cause preterm labor, perinatal mortality, or tissue damage. In the case that the fluid does not reaccumulate, the reduction of amniotic fluid stabilizes the pregnancy. Otherwise the treatment is repeated as necessary. There is no standard procedure for how much fluid is removed each time. There is a danger that if too much fluid is removed, the recipient twin could die. This procedure is associated with a 66% survival rate of at least one fetus, with a 15% risk of cerebral palsy and average delivery occurring at 29 weeks gestation.

Turning the baby, technically known as external cephalic version (ECV), is when the baby is turned by gently pressing the mother’s abdomen to push the baby from a bottom first position, to a head first position. ECV does not always work, but it does improve the mother’s chances of giving birth to her baby vaginally and avoiding a cesarean section. The World Health Organisation recommends that women should have a planned cesarean section only if an ECV has been tried and did not work.

Women who have an ECV when they are 36–40 weeks pregnant are more likely to have a vaginal delivery and less likely to have a cesarean section than those who do not have an ECV. Turning the baby before this time makes a head first birth more likely but ECV before the due date can increase the risk of early or premature birth which can cause problems to the baby.

There are treatments that can be used which might affect the success of an ECV. Drugs called beta-stimulant tocolytics help the woman’s muscles to relax so that the pressure during the ECV does not have to be so great. Giving the woman these drugs before the ECV improves the chances of her having a vaginal delivery because the baby is more likely to turn and stay head down. Other treatments such as using sound, pain relief drugs such as epidural, increasing the fluid around the baby and increasing the amount of fluids to the woman before the ECV could all effect its success but there is not enough research to make this clear.

Turning techniques mothers can do at home are referred to Spontaneous Cephalic Version (SCV), this is when the baby can turn without any medical assistance. Some of these techniques include; a knee to chest position, the breech tilt and moxibustion, these can be performed after the mother is 34 weeks pregnant. Although there is not a lot of evidence to support how well these techniques work, it has worked for some mothers.

This procedure involves the tearing of the dividing membrane between fetuses such that the amniotic fluid of both twins mixes under the assumption that pressure is different in either amniotic sac and that its equilibration will ameliorate progression of the disease. It has not been proven that pressures are different in either amniotic sac. Use of this procedure can preclude use of other procedures as well as make difficult the monitoring of disease progression. In addition, tearing the dividing membrane has contributed to cord entanglement and demise of fetuses through physical complications.

When a baby is born bottom first there is more risk that the birth will not be straight forward and that the baby could be harmed. For example, when the baby's head passes through the mother’s pelvis the umbilical cord can be compressed which prevents delivery of oxygenated blood to the baby. Due to this and other risks, babies in breech position are usually born by a planned caesarean section in developed countries.

Caesarean section reduces the risk of harm or death for the baby but does increase risk of harm to the mother compared with a vaginal delivery. It is best if the baby is in a head down position so that they can be born vaginally with less risk of harm to both mother and baby. The next section is looking at External cephalic version or ECV which is a method that can help the baby turn from a breech position to a head down position.

Vaginal birth of a breech baby has its risks but caesarean sections are not always available or possible, a mother might arrive in hospital at a late stage of her labour or may choose not to have a caesarean section. In these cases, it is important that the clinical skills needed to deliver breech babies are not lost so that mothers and babies are as safe as possible. Compared with developed countries, planned caesarean sections have not produced as good results in developing countries - it is suggested that this is due to more breech vaginal deliveries being performed by experienced, skilled practitioners in these settings.

With so few individuals actually surviving until birth, the only treatment option is surgery to try to remove the parasitic twin. Surgery, however, is very dangerous and has been successful only once. The problem with surgical intervention is that the arterial supplies of the head are so intertwined that it is very hard to control the bleeding, and it has been suggested that cutting off the parasitic twin's arterial supply might improve the odds of the developed twin's survival.

If locked twins are diagnosed in early delivery, before either twin is born, both fetuses can be delivered by Caesarean section. If one fetus has been partially born, attempts can be made to disimpact the twins manually, such as by the Zavanelli maneuver, with a view to performing an assisted delivery with ventouse or forceps. If the diagnosis is made only after the first locked twin has died in the birth canal, or if it is not expected to survive, the first twin may be decapitated and its head pushed up to allow safe delivery of the second twin.

At least one case has been reported where hexoprenaline was used to relax the uterine smooth muscle and thereby temporarily inhibit labour so that the fetal heads could be disimpacted.

Since locked twins are often diagnosed in the late stages of delivery, it is often too late to intervene to save the life of the first twin and thus there is a high rate of stillbirth, estimated to be over 50%.

If left untreated, the pump twin will die in 50–75% of cases.

After diagnosis, ultrasound and amniocentesis are used to rule out genetic abnormalities in the pump twin. A procedure may then be performed which will stop the abnormal blood flow. The acardiac twin may be selectively removed. The umbilical cord of the acardiac twin may be surgically cut, separating it from the pump twin, a procedure called fetoscopic cord occlusion. Or a radio-frequency ablation needle may be used to coagulate the blood in the acardiac twin's umbilical cord. This last procedure is the least invasive. These procedures greatly increase the survival chances of the pump twin, to about 80%.

The pump twin will be monitored for signs of heart failure with echocardiograms. If the pump twin's condition deteriorates, the obstetrician may recommend early delivery. Otherwise, the pregnancy continues normally. Vaginal birth is possible unless the fetus is in distress, although it is recommended that the delivery take place at a hospital with NICU capabilities.

The treatment depends on the cause.

Severely anemic fetuses, including those with Rh disease and alpha thalassemia major, can be treated with blood transfusions while still in the womb. This treatment increases the chance that the fetus will survive until birth.

Retrospective data of over 182,000 births, with the statistical power to determine even mild associations, suggest that a single or multiple nuchal cords at the time of delivery is not associated with adverse perinatal outcomes, is associated with higher birthweights and fewer caesarean sections in births. Although some studies have found that a tight nuchal cord is associated with short term morbidity, it is unclear whether such outcomes are actually a result of the presence of the nuchal cord itself, or as a result of clamping and cutting the cord

Management of a presenting nuchal cord should be tailored to prevent umbilical cord compression whenever possible. Techniques to preserve an intact nuchal cord depend on how tightly the cord is wrapped around the infant’s neck. If the cord is loose, it can easily be slipped over the infant’s head. The infant can be delivered normally and placed on maternal abdomen as desired. If the cord is too tight to go over the infant’s head, the provider may be able to slip it over the infant’s shoulders and deliver the body through the cord. The cord can then be unwrapped from around the baby after birth. Finally, if the cord is too tight to slip back over the shoulders, one may use the somersault maneuver to allow the body to be delivered. The birth attendant may also choose to clamp and cut the umbilical cord to allow for vaginal delivery if other methods of nuchal cord management are not feasible.

A vanishing twin, also known as fetal resorption, is a fetus in a multi-gestation pregnancy which dies in utero and is then partially or completely reabsorbed. In some instances, the dead twin will be compressed into a flattened, parchment-like state known as "fetus papyraceus".

Vanishing twins occur in up to one out of every eight multifetus pregnancies and may not even be known in most cases. "High resorption rates, which cannot be explained on the basis of the expected abortion rate...suggest intense fetal competition for space, nutrition, or other factors during early gestation, with frequent loss or resorption of the other twin(s)."

In pregnancies achieved by IVF, "it frequently happens that more than one amniotic sac can be seen in early pregnancy, whereas a few weeks later there is only one to be seen and the other has 'vanished'."

A parasitic twin (also known as an asymmetrical or unequal conjoined twin) is the result of the processes that also produce vanishing twins and conjoined twins, and may represent a continuum between the two. Parasitic twins occur when a twin embryo begins developing in utero, but the pair does not fully separate, and one embryo maintains dominant development at the expense of its twin. Unlike conjoined twins, one ceases development during gestation and is vestigial to a mostly fully formed, otherwise healthy individual twin. The undeveloped twin is defined as parasitic, rather than conjoined, because it is incompletely formed or wholly dependent on the body functions of the complete fetus.

The independent twin is called the autosite.

Craniopagus parasiticus is an extremely rare type of parasitic twinning occurring in about 4 to 6 of 10,000,000 births. In craniopagus parasiticus, a parasitic twin head with an undeveloped body is attached to the head of a developed twin. Fewer than a dozen cases of this type of conjoined twin have been documented in the literature. Most infants with this condition are stillborn, or die shortly after birth.

Twin reversed arterial perfusion sequence—also called TRAP sequence, TRAPS, or acardiac twinning—is a rare complication of monochorionic twin pregnancies. It is a severe variant of twin-to-twin transfusion syndrome (TTTS). The twins' blood systems are connected instead of independent. One twin, called the "acardiac twin" or "TRAP fetus", is severely malformed. The heart is missing or deformed, hence the name acardiac, as are the upper structures of the body . The legs may be partially present or missing, and internal structures of the torso are often poorly formed. The other twin is usually normal in appearance. The normal twin, called the "pump twin", drives blood through both fetuses. It is called "reversed arterial perfusion" because in the acardiac twin the blood flows in a reversed direction.

TRAP sequence occurs in 1% of monochorionic twin pregnancies and in 1 in 35,000 pregnancies overall.

Surgery to separate conjoined twins may range from very easy to very difficult depending on the point of attachment and the internal parts that are shared. Most cases of separation are extremely risky and life-threatening. In many cases, the surgery results in the death of one or both of the twins, particularly if they are joined at the head or share a vital organ. This makes the ethics of surgical separation, where the twins can survive if not separated, contentious. Alice Dreger of Northwestern University found the quality of life of twins who remain conjoined to be higher than is commonly supposed. Lori and George Schappell and Abby and Brittany Hensel are notable examples.

In 1955, neurosurgeon Harold Voris (1902-1980) and his team at Mercy Hospital in Chicago performed the first successful operation to separate Siamese twins conjoined (Craniopagus twins) at the head, which resulted in long-term survival for both. The larger girl was reported in 1963 as developing normally, but the smaller was permanently impaired.

In 1957, Bertram Katz and his surgical team made international medical history performing the world's first successful separation of conjoined twins sharing a vital organ. Omphalopagus twins John Nelson and James Edward Freeman (Johnny and Jimmy) were born to Mr. and Mrs. William Freeman of Youngstown, Ohio, on April 27, 1956. The boys shared a liver but had separate hearts and were successfully separated at North Side Hospital in Youngstown, Ohio by Bertram Katz. The operation was funded by the Ohio Crippled Children's Service Society.

Recent successful separations of conjoined twins include that of the separation of Ganga & Jamuna Shreshta in 2001, who were born in Kathmandu, Nepal, in 2000. The 197-hour surgery on the pair of craniopagus twins was a landmark one which took place in Singapore; the team was led by neurosurgeons Chumpon Chan and Keith Goh. The surgery left Ganga with brain damage and Jamuna unable to walk. Seven years later, Ganga Shrestha died at the Model Hospital in Kathmandu in July 2009, at the age of 8, three days after being admitted for treatment of a severe chest infection.

A case of particular interest was that of infants Rose and Grace ("Mary" and "Jodie") Attard, conjoined twins from Malta who were separated in Great Britain by court order over the religious objections of their parents, Michaelangelo and Rina Attard. The surgery took place in November, 2000, at St Mary's Hospital in Manchester. The operation was controversial because Rose, the weaker twin, would die as a result of the procedure as her heart and lungs were dependent upon Grace's. (The twins were attached at the lower abdomen and spine.) However, if the operation had not taken place, it was certain that both twins would die. Grace survived to enjoy a normal childhood.

In 2003 two 29-year-old women from Iran, Ladan and Laleh Bijani, who were joined at the head but had separate brains (craniopagus) were surgically separated in Singapore, despite surgeons' warnings that the operation could be fatal to one or both. Their complex case was accepted only because high tech graphical imagery and modelling would allow the medical team to plan the risky surgery. Unfortunately, an undetected major vein hidden from the scans was discovered during the operation. The separation was completed but both women died while still in surgery on July 8, 2003.

Surgical treatment should be considered when the patient has a trigger thumb bilaterally and when the patient has a severe trigger thumb. Severe is defined as when the thumb is locked so that the thumb cannot be flexed or extended either passively or actively. Surgical treatment should also be considered when observation and/or splint therapy hasn’t achieved sufficient results after 49 months. Unlike the surgical treatment given for adults, which is unambiguously a surgical release of the A1 pulley of the thumb, the optimum surgical treatment for infants has not yet been discerned. In case of infants, research has shown that only in 15% of the cases A1 pulley release alone is sufficient. In most of the cases there was an additional annular pulley structure distal to the A1 to be released resolving the triggering: the so-called Av pulley or variable pulley. Therefore infants and adults need to be treated differently as the main problem is different.

There are several types of treatment for congenital trigger thumb, conservative and surgical.

Soothing mild cases during pregnancy consists mainly of the application of topical moisturising creams or aqueous/emollient ointments. Class I or II corticosteroid creams and ointments are used in more aggressive cases, and oral (systemic) corticosteroids can be used to treat very severe cases—although the benefits of a pregnant woman's ingesting high-potency corticosteroids must be weighed carefully against possible (and mostly unknown) risks to the developing fetus or fetuses. Rarely, in unusually persistent and distressing cases, some women have had their labor induced as soon as they are considered to be at term (37 weeks).

Antihistamine tablets may be prescribed to provide relief from the itch, although they are generally considered much less effective than corticosteroid treatments, and may act as little more than a sleep aid.

Pine tar soap/body wash can bring relief as can keeping the skin chilled such as through a cold shower or iced cloths.

In the majority of cases, PUPPP resolves spontaneously within a week of delivery. However, a few women continue to experience symptoms long into the postpartum period.

In order to treat a Bochdalek hernia, the baby's physician must take into account multiple factors. First, the diagnosis will vary depending on whether the Bochdalek hernia was found during fetal development or after birth. "The key to survival lies in prompt diagnosis and treatment." Second, the baby's overall health and medical history will be evaluated. Third, the doctor will look at the seriousness of the condition. Fourth, the baby will need to be evaluated at the level of medication, procedure and therapy he or she can handle, and finally, the doctor will take into consideration the opinion and preference of the parents. After these things are all taken into consideration and evaluated, the doctor will determine how to treat the baby. There are three different treatments available. The first treatment includes the baby's admission into the NICU (Neonatal Intensive Care Unit). In most Bochdalek Hernia cases, babies who are admitted in the NICU, are placed on a mechanical ventilator to help breathing. Another treatment involves putting the infants on a temporary heart/lung bypass machine, called an ECMO. This normally pertains to children who have severe problems. ECMO performs the tasks the regularly functioning hearts and lungs do. ECMO allows oxygen to be regulated into the blood and then pumps the blood throughout the entire body. Normally, this machine is used to stabilize the baby's condition. The third option in treatment is surgery.

After the baby is stable and his or her state has improved, the diaphragm can be fixed and the misplaced organs can be relocated to their correct position. Although these are various treatments for Bochdalek Hernias, it does not guarantee the baby will survive. Since the baby must go through some or all of the previous treatments, the baby's hospital stay is usually longer than that of a "normal" newborn. The average infants born with a Bochdalek Hernia stay in the hospital between 23.1 and 26.8 days.

Hydrops fetalis is a condition in the fetus characterized by an accumulation of fluid, or edema, in at least two fetal compartments. By comparison, hydrops allantois or hydrops amnion is an accumulation of excessive fluid in the allantoic or amniotic space, respectively.

Lip pits may be surgically removed either for aesthetic reasons or discomfort due to inflammation caused by bacterial infections or chronic saliva excretion, though spontaneous shrinkage of the lip pits has occurred in some rare cases. Chronic inflammation has also been reported to cause squamous-cell carcinoma. It is essential to completely remove the entire lip pit canal, as mucoid cysts can develop if mucous glands are not removed. A possible side effect of removing the lip pits is a loose lip muscle. Other conditions associated with VWS, including CL, CP, congenital heart defects, etc. are surgically corrected or otherwise treated as they would be if they were non-syndromic.

The girls underwent a six-week period for physical therapy and recovery. Maria and Teresa are now able to walk independently and are starting to form their own individual personalities. The girls were able to return to the Dominican Republic and often return to the United States for follow-up care.

Medical management may involve immunosuppressive drugs such as methotrexate, corticosteroids, cyclophosphamide, and azathioprine. No randomized controlled trials have yet been conducted to evaluate such treatments, so the benefits have not been clearly established.

Craniopagus twins are conjoined twins that are fused at the cranium. This condition occurs in about 10–20 babies in every million births in the United States. Among this small group, cephalic conjoining, or craniopagus twinning, represents the rarest of congenital abnormalities, accounting for 2–6% of all conjoined twins. Additionally, conjoined twins are genetically identical and always share the same sex. The union in craniopagus twins may occur on any portion of the Calvary, but does not include either the face or the foramen magnum. The thorax and abdomen are separate and each twin has its own umbilicus and umbilical cord. The union may involve the entire diameter of the head or only a small portion. This suggests that although there are many different kinds of vulnerabilities already known in the scientific community, there are an infinite number of variations that can occur. Most of these variations are based on the rotation of one twin's skull to the other and the different phenotype sub-groups of craniopagus twins are based on all these rotational conformations. Each of these factors (rotation, spot of union) affects the development of the brain, the vascular system within the brain and overall wellness of life both of the twins have outside the womb. Relatively few craniopagus twins survive the perinatal period – approximately 40% of conjoined twins are stillborn and an additional 33% die within the immediate perinatal period, usually from organ abnormalities and failure. However 25% of craniopagus twins survive and can be considered for a surgical separation and several attempts occur yearly worldwide. In the last-half century, many advances in medicine including brain imaging, neuro-anesthesia and neurosurgical techniques have proven that a successful outcome is possible following separation of total craniopagus twins.

Only a few individuals who did not have fatal kidney and bladder complications are known to have survived beyond birth with this condition.