A number of medications may be useful to delay delivery including: NSAIDs, calcium channel blockers, beta mimetics, and atosiban. Tocolysis rarely delays delivery beyond 24–48 hours. This delay however may be sufficient to allow the pregnant woman to be transferred to a center specialized for management of preterm deliveries and give administered corticosteroids to reduce neonatal organ immaturity. Meta-analyses indicate that calcium-channel blockers and an oxytocin antagonist can delay delivery by 2–7 days, and β2-agonist drugs delay by 48 hours but carry more side effects. Magnesium sulfate does not appear to be useful and may be harmful when used for this purpose.

Reduction in activity by the mother – pelvic rest, limited work, bed rest – may be recommended although there is no evidence it is useful with some concerns it is harmful. Increasing medical care by more frequent visits and more education has not been shown to reduce preterm birth rates. Use of nutritional supplements such as omega-3 polyunsaturated fatty acids is based on the observation that populations who have a high intake of such agents are at low risk for preterm birth, presumably as these agents inhibit production of proinflammatory cytokines. A randomized trial showed a significant decline in preterm birth rates, and further studies are in the making.

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.

A Cochrane review concluded that "simple maternal hydration appears to increase amniotic fluid volume and may be beneficial in the management of oligohydramnios and prevention of oligohydramnios during labour or prior to external cephalic version."

In severe cases oligohydramnios may be treated with amnioinfusion during labor to prevent umbilical cord compression. There is uncertainty about the procedure's safety and efficacy, and it is recommended that it should only be performed in centres specialising in invasive fetal medicine and in the context of a multidisciplinary team.

In case of congenital lower urinary tract obstruction, fetal surgery seems to improve survival, according to a randomized yet small study.

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.

Fetuses with polyhydramnios are at risk for a number of other problems including cord prolapse, placental abruption, premature birth and perinatal death. At delivery the baby should be checked for congenital abnormalities.

Drugs used during pregnancy can have temporary or permanent effects on the fetus. Anything (including drugs) that can cause permanent deformities in the fetus are labeled as teratogens. In the U.S., drugs were classified into categories A, B, C, D and X based on the Food and Drug Administration (FDA) rating system to provide therapeutic guidance based on potential benefits and fetal risks. Drugs, including some multivitamins, that have demonstrated no fetal risks after controlled studies in humans are classified as Category A. On the other hand, drugs like thalidomide with proven fetal risks that outweigh all benefits are classified as Category X.

The first step in management of uterine atony is uterine massage. The next step is pharmacological therapies, the first of which is oxytocin, used because it initiates rhythmic contractions of the uterus, compressing the spiral arteries which should reduce bleeding. The next step in the pharmacological management is the use of methylergometrine, which is an ergot derivative, much like that use in the abortive treatment of migraines. Its side effect of hypertension means its use should not be used in those with hypertension or pre-eclampsia. In those with hypertension, the use of prostaglandin F is indicated (but beware of its use in patients with asthma).

Another option Carbetocin and Carboprost where Oxytocin and ergometrin is inappropriate.

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.

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.

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.

Polyhydramnios (polyhydramnion, hydramnios, polyhydramnios) is a medical condition describing an excess of amniotic fluid in the amniotic sac. It is seen in about 1% of pregnancies. It is typically diagnosed when the amniotic fluid index (AFI) is greater than 24 cm.

There are two clinical varieties of polyhydramnios:

- Chronic polyhydramnios where excess amniotic fluid accumulates gradually

- Acute polyhydramnios where excess amniotic fluid collects rapidly

The opposite to polyhydramnios is oligohydramnios, a deficiency in amniotic fluid.

Nutrition during pregnancy is important to ensure healthy growth of the fetus. Nutrition during pregnancy is different from the non-pregnant state. There are increased energy requirements and specific micronutrient requirements. Women benefit from education to encourage a balanced energy and protein intake during pregnancy. Some women may need professional medical advice if their diet is affected by medical conditions, food allergies, or specific religious/ ethical beliefs.

Adequate periconceptional (time before and right after conception) folic acid (also called folate or Vitamin B) intake has been shown to decrease the risk of fetal neural tube defects, such as spina bifida. The neural tube develops during the first 28 days of pregnancy, a urine pregnancy test is not usually positive until 14 days post-conception, explaining the necessity to guarantee adequate folate intake before conception. Folate is abundant in green leafy vegetables, legumes, and citrus. In the United States and Canada, most wheat products (flour, noodles) are fortified with folic acid.

DHA omega-3 is a major structural fatty acid in the brain and retina, and is naturally found in breast milk. It is important for the woman to consume adequate amounts of DHA during pregnancy and while nursing to support her well-being and the health of her infant. Developing infants cannot produce DHA efficiently, and must receive this vital nutrient from the woman through the placenta during pregnancy and in breast milk after birth.

Several micronutrients are important for the health of the developing fetus, especially in areas of the world where insufficient nutrition is common. Women living in low and middle income countries are suggested to take multiple micronutrient supplements containing iron and folic acid. These supplements have been shown to improve birth outcomes in developing countries, but do not have an effect on perinatal mortality. Adequate intake of folic acid, and iron is often recommended. In developed areas, such as Western Europe and the United States, certain nutrients such as Vitamin D and calcium, required for bone development, may also require supplementation. Vitamin E supplementation has not been shown to improve birth outcomes. Zinc supplementation has been associated with a decrease in preterm birth, but it is unclear whether it is causative. Daily iron supplementation reduces the risk of maternal anemia. Studies of routine daily iron supplementation for pregnant women found improvement in blood iron levels, without a clear clinical benefit. The nutritional needs for women carrying twins or triplets. are higher than those of women carrying one baby.

Women are counseled to avoid certain foods, because of the possibility of contamination with bacteria or parasites that can cause illness. Careful washing of fruits and raw vegetables may remove these pathogens, as may thoroughly cooking leftovers, meat, or processed meat. Unpasteurized dairy and deli meats may contain "Listeria," which can cause neonatal meningitis, stillbirth and miscarriage. Pregnant women are also more prone to "Salmonella" infections, can be in eggs and poultry, which should be thoroughly cooked. Cat feces and undercooked meats may contain the parasite Toxoplasma gondii and can cause toxoplasmosis. Practicing good hygiene in the kitchen can reduce these risks.

Women are also counseled to eat seafood in moderation and to eliminate seafood known to be high in mercury because of the risk of birth defects. Pregnant women are counseled to consume caffeine in moderation, because large amounts of caffeine are associated with miscarriage. However, the relationship between caffeine, birthweight, and preterm birth is unclear.

Many factors determine the optimal way to deliver a baby. A vertex presentation is the ideal situation for a vaginal birth, however, occiput posterior positions tend to proceed more slowly, often requiring an intervention in the form of forceps, vacuum extraction, or Cesarean section. In a large study, a majority of brow presentations were delivered by Cesarean section, however, because of 'postmaturity', factors other than labour dynamics may have played a role. Most face presentations can be delivered vaginally as long as the chin is anterior; there is no increase in fetal or maternal mortality. Mento-posterior positions cannot be delivered vaginally in most cases (unless rotated) and are candidates for Cesarean section in contemporary management.

Oligohydramnios is a condition in pregnancy characterized by a deficiency of amniotic fluid. It is the opposite of polyhydramnios.

Common risks in LGA babies include shoulder dystocia, hypoglycemia, metatarsus adductus, hip subluxation and talipes calcaneovalgus due to intrauterine deformation.

Shoulder dystocia can result from the anterior shoulder becoming impacted on the maternal symphysis pubis. The doctor or midwife will try to push the baby's anterior shoulder downward to pass through the birth canal and clear the woman's symphysis pubis. This can be difficult if the child is LGA, since the birth canal is 10 cm when fully dilated for most women and there may not be much room to move the baby. If shoulder dystocia occurs, there are various manoeuvres which can be performed by the birth attendant to try to deliver the shoulders. These generally involve trying to turn the shoulders into the oblique, using suprapubic pressure to disimpact the anterior shoulder from above the symphysis pubis, or delivering the posterior arm first. If these do not resolve the situation, the provider may intentionally snap the baby's clavicle (bone that holds shoulder in place) in order to displace the shoulder and allow the child to be delivered. The bone should heal spontaneously, and most babies will make a full recovery from this birth injury.. There is still a risk of temporary or permanent nerve damage to the baby's arm, or other injuries such as humeral fracture.

Although big babies are at higher risk for shoulder dystocia, most cases of shoulder dystocia happen in smaller babies because there are many more small and normal-size babies being born than big babies. Researchers have found that it is impossible to predict who will have shoulder dystocia and who will not.

In non-diabetic women, shoulder dystocia happens 0.65% of the time in babies that weigh less than , 6.7% of the time in babies that weigh to , and 14.5% of the time in babies that weigh more than .

Big babies are at higher risk of hypoglycemia in the neonatal period, independent of whether the mother has diabetes.

The gold standard for treatment of umbilical cord prolapse in the setting of a viable pregnancy typically involves immediate delivery by the quickest and safest route possible. This usually requires cesarean section, especially if the woman is in early labor. Occasionally, vaginal delivery will be attempted if clinical judgment determines that is a safer or quicker method.

Other interventions during management of cord prolapse are typically used to decrease the chance of complications while preparations for delivery are being made. These interventions are focused on reducing pressure on the cord to prevent fetal complications from cord compression. The following maneuvers are among those used in clinical practice:

- manual elevation of the presenting fetal part

- repositioning of the mother to be head down with feet elevated

- filling of the bladder with a foley catheter, or tube through the urethra to elevate the presenting fetal part

- use of tocolytics (medications to suppress labor) have been proposed, usually in addition to bladder filling rather than a standalone intervention

If the mother is far from delivery, funic reduction (manually placing the cord back into the uterine cavity) has been attempted, with successful cases reported.

Available treatments address the symptoms of CCD, not the underlying defect. Early diagnosis and aggressive salt replacement therapy result in normal growth and development, and generally good outcomes. Replacement of NaCl and KCl has been shown to be effective in children.

A potential treatment is butyrate.

There are believed to be links with polyhydramnios (excessive amniotic sac fluid). If one has excessive amniotic fluid, microsomia is more likely, since there is no room for the baby to grow. Preterm labor is also highly likely for polyhydramnios.

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.

Mirror syndrome or triple oedema or Ballantyne syndrome is a rare disorder affecting pregnant women. It describes the unusual association of fetal

and placental hydrops with maternal preeclampsia.

The name "mirror syndrome" refers to the similarity between maternal oedema and fetal hydrops. It was first described in 1892 by John William Ballantyne.

The delivery of the second twin in a transverse lie with a shoulder presentation represents a special situation that may be amenable to a vaginal delivery. As the first twin has just been delivered and the cervix is fully dilated the obstetrician may perform an internal version, that is inserting one hand into the uterus, find the baby’s feet, and then bring the baby into a breech position and deliver the baby as such.

Pregnancy does not have an adverse effect on the course of Behçet's disease and may possibly ameliorate its course. Still, there is a substantial variability in clinical course between patients and even for different pregnancies in the same patient. Also, the other way around, Behçet's disease confers an increased risk of pregnancy complications, miscarriage and Cesarean section.

While a transverse lie prior to labor can be manually versed to a longitudinal lie, once the uterus starts contracting the uterus normally will not allow any version procedure. A shoulder presentation is an indication for a caesarean section. Generally, as it is diagnosed early, the baby is not damaged by the time of delivery. With the rupture of the membranes, there is an increased risk of a cord prolapse as the shoulder may not completely block the birth canal. Thus the caesarean section is ideally performed before the membranes break.

In most cases Ballantyne syndrome causes fetal or neonatal death and in contrast, maternal involvement is limited at the most to preeclampsia.