Oligohydramnios

Oligohydramnios is the condition of having too little amniotic fluid. About 8 per cent of all pregnant women are found to have low amniotic fluid at some point, usually in their third trimester. Among those still pregnant two weeks past their due date, 12 per cent have this condition. Amniotic fluid provides the fetus with fluid and nutrients, protects the fetus from trauma, has antibacterial properties and is necessary for the development of a healthy fetus. Studies have suggested that dramatic changes in amniotic fluid volumes can be a reflection of abnormalities in maternal or fetal status increasing the risk of perinatal morbidity and mortality.

The volume of amniotic fluid is ultimately determined by the volume of fluid flowing into and out of the amniotic sac. Fetal urination, lung fluid, and swallowing all make important contributions to fluid movement in late gestation, with minimal contributions from other sources. Fetal disorders that affect any of these processes.

What causes oligohydramnios?

Birth defects – Problems with the development of the kidneys or urinary tract which could cause little urine production, leading to low levels of amniotic fluid.

Placental problems – If the placenta is not providing enough blood and nutrients to the baby, then the baby may stop recycling fluid.

Leaking or rupture of membranes – This may be a gush of fluid or a slow constant trickle of fluid. This is due to a tear in the membrane. Premature rupture of membranes (PROM) can also result in low amniotic fluid levels.

Post Date Pregnancy - A post date pregnancy (one that goes over 42 weeks) can have low levels of amniotic fluid, which could be a result of declining placental function.

Maternal Complications - Factors such as maternal dehydration, hypertension, preeclampsia, diabetes, and chronic hypoxia can have an effect on amniotic fluid levels.

Medications - Certain drugs may cause oligohydramnios. Some drugs are used for management of high blood pressure, should be avoided in pregnancy as they affect the baby's kidney function. Certain drugs used to postpone premature labour such as indomethacin or even ibuprofen may also affect the kidney function of the baby. Talk to your doctor if you need to use these medications during your pregnancy.

An unusually large number of diagnoses seem to be made that "there is not enough amniotic fluid." It is important for parents to know that this is likely an inaccurate assessment. The diagnosis is confirmed by ultrasounds. An ultrasound examination during the second and/or third trimester of a pregnancy is a good tool to help detect the presence of oligohydramnios but it should not dictate to mothers that it is the only way. Ultrasound evaluations of amniotic fluid volumes are becoming a standard part of antepartum assessment of fetal well-being with variances in fluid levels leading to interventions that can increase the risk to both mother and baby. So, here's the point. If your doctor says, "Your fluid is low, we need to induce," don't blink blindly and say, "OK." The problem is that it is very often hard to determine "oligo" with certainty.

This measurement is commonly taken by using an ultrasound to determine the Amniotic Fluid Index (AFI). The AFI was introduced in 1987 to replace the 2 cm “pocket technique” of fluid assessment, and studies continue to question to what extent the AFI reflects actual amniotic fluid volume. The most recent studies say that the AFI is not a great predictor of the Amniotic fluid volume (actual amount of fluid. Doctors want to know the results of a Biophysical Profile to see what is going on. A biophysical profile is a simple, painless test that's performed during pregnancy to assess a foetus's well-being – specifically, whether he's getting enough oxygen inside the uterus or not.

The following criteria are assessed during a biophysical profile:

• Amniotic fluid index (AFI) – four pockets of fluid are measured; two pockets must measure 2 cm or more for a score of 2
• Fetal breathing – fetuses "practice breathing" by contracting and relaxing the diaphragm muscle; a score of 2 is assigned for fetal breathing lasting 30 seconds or more
• Fetal tone – the full extension and flexion of a limb such as opening and closing a hand
• Gross body movements – two or three episodes of movement such as squirming or kicking.

Pregnant women should ask questions such as can I get some fluids (IV, etc.) and retest? Here's some additional good info on AFI here esp relevant to "post-dates" pregnancy.

I have been seeing so many women who say their doctor wants to do a repeat ultrasound or just go ahead and induce on a certain day because it looks like the amniotic fluid is  low. These test can be sometimes so innaccurate and midwives should make people aware of this unnecessary intervention. Women should think twice before agreeing to the an induction. They should ask questions and every question posted should be answered by midwives and OB/GYN.


What I have found is most often, a woman will refuse induction on or around her due date. The doctor, for fear of liability, will order her to come in once or twice a week for non-stress tests (NST or CTG), in which they measure her amniotic fluid. These doctors will then tell the pregnant woman her fluid level is low, and they now have a medical reason to induce, and will promptly send her to the hospital. This tactic seems to be a way to convince a woman to do what the doctor tells her to by scaring her with medical jargon.

What treatment options are available for women with oligohydramnios?

A Cochrane systematic review by Hofmeyr and Gulmezoglu concluded that maternal hydration appears to increase amniotic fluid and may be beneficial in management of oligohydramnios. The amount of fluids a woman drinks daily directly influences the amount of fluid in your uterus. A 2009 study in the "Journal of Obstetrics and Gynaecology Research" demonstrated that pregnant women who had low amounts of amniotic fluid were able to increase the amount of amniotic fluid through oral hydration.

Since low amniotic fluid levels are more common during the summer, pregnant women should be advised careful to drink at least 10 cups of fluids daily, according to the Institute of Medicine. The majority of your fluids should be water, although you can also get fluids from decaffeinated tea, soup and fruit juices. Midwives should advise pregnant women to stay hydrated and monitor the baby's movements. Pregant women should take responsibility for the life they're carrying inside of them and should drink more water though I feel it is an effort for most of them.

Also, to improve the Amniotic fluid level Glucose, coconut water, water, fresh juices, etc should be consumed. Drinking tender coconut water in morning and evening will increase weight of baby also. Watermelon is also a good item to consumed during summer time when the water level in pregnant women decreases. Drink 1 glass of water every half an hour and pass urine at least once in a hour. Fluids will help with hydration. The body can't make fluid without it. Water is an important part of pregnancy. The fluid acts as the body's transportation system, and carries nutrients through the blood to the baby. This will help in preventing urinary infection also.

References
Boyd, R.L. & Carter, B.S. (2002). Polyhydramnios and Oligohydramnios. e Medicine.
Retrieved from http://www.emedicine.com/

Hofmeyr, G. J., Gulmezoglu, A. M. (2002). Maternal hydration for increasing amniotic fluid volume in oligohydramnios and normal amniotic fluid volume. In: The Cochrane Library, Issue 1,  Oxford: Updated Software.

Mozurkewich, E., Chilimigras, J., Koepke, E. et al. (2009).  Indications for induction of labour: a best-evidence review. BJOG. 116(5):626-36.

Phelan, J. P., Smith, C. V., Broussard, P., Small, M. (1987). Amniotic fluid volume assessment with the four-quadrant technique at 36–42weeks’ gestation. J Reprod Med. 32:540–542.

Polyhydramnios

Polyhydramnious or hydramnious is as an abnormally large volume of amniotic fluid. There is a range of 'normal' fluid volumes and an abnormally large volume may raise suspicion of a problem with the pregnancy. Greater deviations from the norm are more strongly associated with abnormality. The definition of "too much" is generally considered to be more than 2 liters; the average amount is about 1 liter, see  "Assessment of amniotic fluid volume".). Most cases of polyhydramnios are mild and involve less than 3 liters of amniotic fluid. So, in many cases, a diagnosis of polyhydramnios means that you're on the high side of normal for amount of amniotic fluid and presents only minor secondary concerns.

Polyhydramnios occurs in about 1 pregnancy out of 100; 95% of those are considered mild to moderate. The symptoms of hydramnios can include rapid growth of the uterus, discomfort in the abdomen, and possibly uterine contractions, but more often than not, there are no symptoms at all.

Pathogenesis

Physiologically, the volume of fluid increases with gestation to a maximum of 800-1,000 ml at 36-37 weeks. It has a number of purposes, including protecting the fetus from trauma and infection, allowing lung development and facilitating the development and movement of the limb and other skeletal parts. Fetal swallowing causes a reduction in the volume of fluid and absence of swallowing or a blockage of the fetal gastrointestinal tract may lead to polyhydramnios. Polyhydramnios is therefore linked to fetal abnormality.

Most women diagnosed with the condition deliver healthy babies. Most of the time, a little extra amniotic fluid is nothing to be concerned about. Such extra fluid is likely to be reabsorbed without any treatment. But when fluid accumulation is severe, it may signal a problem with the baby such as a central nervous system or gastrointestinal defect, kidney or bladder malfunction, or a problem with the baby's ability to swallow.

What causes polyhydramnios?

The causes of polyhydramnios are not completely understood. In many cases it's difficult to say what causes polyhydramnios but there are a few circumstances that make the condition more likely:

■Multiple / twin pregnancies - you're more likely to have abnormal amniotic fluid levels if you're carrying twins or other multiples. The cause of this is often twin-to-twin transfusion syndrome, where one twin has too little amniotic fluid and the other has too much.

 ■Gestational diabetes - greatly increases the likelihood of polyhydramnios. Around one in ten pregnant women with diabetes will develop some degree of excess amniotic fluid. If diabetes is uncontrolled or poorly controlled in pregnancy, there is a much higher incidence of polyhydramnios and the excessive amount of amniotic fluid is a direct result of the unstable diabetes.

 ■Infection - certain infections such as rubella, toxoplasmosis and syphilis may lead to polyhydramnios. These can be checked for with blood tests.

 ■Fetal abnormalities - in about a fifth of cases, excess amniotic fluid may build up when the baby has difficulties swallowing or digesting the amniotic fluid, preventing the fluid from being recycled. This could be caused by an obstruction in the baby's throat (such as cleft lip or palate) or gastrointestinal tract, or by a neurological problem. Polyhydramnios is also associated with problems with the baby's heart, kidneys and with chromosomal abnormalities.

Risk factors

In addition, too much amniotic fluid can put your pregnancy at risk for premature rupture of your membranes, premature labour, placental abruption, breech baby presentation, postpartum haemorrhage or umbilical cord prolapse.

Polyhydramnios increases the risk of postpartum haemorrhage simply because the uterus has been distended more than is usual for a singleton pregnancy.

Polyhydramnios increases the risk of placental abruption because of the mechanical forces at work in separating the placenta from the uterus. Polyhydramnios increases the risk of cord prolapse for several reasons. First, because the baby's presentation is unpredictable, the baby may be in an unfavorable position when the membranes rupture, and the presenting part may not fit into the pelvis well enough to keep the cord from falling out below. Second, because there is so much fluid, there is more pressure on the movable umbilical cord to move it out past the presenting part. If your waters do break before the start of labour you will be advised to lie down and stay reasonably still before going to hospital to reduce the likelihood of a prolapsed umbilical cord.

Growth restriction (IUGR) resulting in skeletal malformations

Stillbirth occurs in about 4 in 1000 pregnancies that suffer from polyhydramnios vs. about 2 in1000 pregnancies with normal fluid levels.

Signs and symptoms

Women might complain of abdominal girth, shortness of breath, oedema of ankles, tense abdomen.  The woman might be restless, abdominal skin might look shiny, difficult to palpate, malpresentation and abnormal lie of the foetus

Management

The first step is to identify any underlying cause. Mild polyhydramnios can be simply monitored and treated conservatively. Pre-term labour is common due to overdistension of the uterus, and measures should be taken to minimise this complication. This includes regular antenatal checks and inspection of the uterus, and bed rest towards the latter stages. Polyhydramnios during pregnancy does not have a harmful effect on the development of the baby or on the woman after delivery, and there is no evidence to suggest that it will recur in a subsequent pregnancy. Bedrest is needed.

Mbilu, J. N. K. (2002). Essentials of Obstetrics and Gynaecology for Clinical Officers and Midwives. Volume 1. Writers Club Press. Lincoln. NE.

Beloosesky, R., Ross, M. G. (2010). Polyhydramnios. UpToDate.

Yeast J. (2006). Polyhydramnios: etiology, diagnosis and management. Neoreviews. 7: 6 e300

Meconium

Meconium comes from the Greek word "meconi" which means poppi juice or opium. Meconuim is composed of all the substances that have built up in the baby’s gut during pregnancy. Meconuim is a sterile compound and is mostly water (70-80% and a number of other interesting ingredients: small bile pigment, bile acids, residue of intestinal secretions, mucus glycoprotein’s, lips and proteases etc. About 15% of babies are born with meconuim stained liquor (MAS).

Meconuim stained liquor occurs when the baby inhales meconuim during labour, birth or immediately following birth. You can see a simple explanation of MAS in utero here. Many theories have been proposed to explain the passage of meconium in utero; however, the precise mechanisms remain unclear. The fetal bowel has little peristaltic action and the anal sphincter is contracted. It is thought that hypoxia and academia cause the anal sphincter to relax, whilst at the same time increasing the production of motilin, which promotes peristalsis.

Risk factors that may cause stress on the baby before birth include:

• Aging" of the placenta if the pregnancy goes far past the due date
• Decreased oxygen to the infant while in the uterus
• Diabetes in the pregnant mother
• Difficult delivery or long labour
• High blood pressure in the pregnant mother
• Smoking
• Direct pushing
• Lack of antenatal care
• Cord involvement
• Natural therapies
• Rupture of membranes early

Induction of labour is a strong risk factor. We know that we see more meconium in induced babies. A logical guess may be that we see more meconium in postdates babies simply because postdates babies are far more likely to be induced than are 40 week.

A careful review of the recent literature indicates clearly that a policy of non-suctioning is as safe as routine suctioning at the perineum for infants born with meconium-stained amniotic fluid. Risks of intrapartum suctioning include causing the fetus to “gasp,” and causing vagal stimulation and postnatal fetal depression and / or bradycardia. Instead, the baby should be transferred quickly to the neonatal team, who will initiate  management of the neonatal airways as indicated. Evidence of the effectiveness of intrapartum suctioning comes from the results of a single retrospective cohort study indicating a non-significant trend towards improved outcomes. The results of that study have been subsequently contradicted by two other studies showing equivalent outcomes with no intrapartum suctioning.

If meconium is present during labour and birth, the pregnant should be watched more closely for signs of fetal distress. Alone, meconium staining of the amniotic fluid does not mean that a baby is suffering from fetal distress. However, since it is one sign, the labour and birth team will look for others signs and continue with the pregnancy as normal as possible without causing any discomfort.

Unsworth, J., Vause, S. (2010). Meconuim in Labour. Obstetrics, Gynaecology & Reproductive Medicine, Volume 20, Issue 10, October 2010, Pages 289-294

Amniotic Fluid

Amniotic fluid is the fluid that surrounds the fetus. Amniotic fluid is 98% water and 2% salts and cells from the baby. A pregnant woman carries about 500-1000 ml of amniotic fluid. Until the fetal kidneys started working during month four, amniotic fluid is made by the mother’s body. But after month 4, the foetus started to make his/her contribution to the amniotic fluid by urinating into it. Successful pregnancy requires the accumulation of significant amounts of water, both to support fetal growth and to allow for maternal physiologic changes.

So let’s say amniotic fluid is to be found in the amniotic cavity. It completely surrounds the embryo after the 4th week of pregnancy. In this way it insures:

• Freedom of movement for the embryo.
• Space for development of the respiratory, digestive and musculoskeletal systems.
• Absorbs blows against the mother's abdomen.
• It has antibacterial properties that provide some protection from infection.
• Serves as a back up of nutrients and fluids for the baby.
• Protect the foetus from heat loss by helping to regulate the correct foetal body temperature.
• Keeps the embryo from sticking to the placenta. Towards the outside, the amniotic cavity is delimited by the amniotic epithelium, the chorionic leave and the deciduas’ capsularis.

The amniotic fluid is a clear, watery fluid that is filtered out of the maternal blood via the amniotic epithelium into the amniotic cavity. A large portion stems also from the fetus itself (from the skin, the umbilical cord, the lungs and the kidneys). The makeup of the amniotic fluid is thus quite complex, with many maternal and fetal constituents. The main constituents are water and electrolytes (99%) together with glucose, lipids from the fetal lungs, proteins with bactericide properties and flaked-off fetal epithelium cells (they make a prenatal diagnosis of the infantile karyotype possible). Its quantity changes over the course of the pregnancy (20 ml in the 7th week, 600 ml in the 25th week, 1000 ml in the 30th to 34th week and 800 ml at birth). From the 5th month the fetus also begins to drink amniotic fluid (400 ml/day). Close to the end of the pregnancy the amniotic fluid is replaced all 3 hours, stressing the importance of this exchange between the amniotic fluid and the maternal compartment.

Amniotic fluid is also important for the health of the mother. This fluid fills the whole womb, so as the foetus grows and gains weight, no pressure is exerted on the womb itself. If this fluid were not present, the growing foetus would weigh the uterus down and the counter-pressure exerted by the uterine walls would make the normal development of the foetus impossible.

If there is a single problem with the production of this fluid, with its continuous purification or the adjustment of its volume, the natural development of the foetus is impaired. For example, if the amount of amniotic fluid is less than required, or if it is not present at all, a series of abnormalities begins to appear. Limbs wither and become deformed, joints fuse, skin loosens and, because of pressure, the face is deformed. The most serious problem is that the development of the lungs is impeded and the baby dies immediately after birth.

 

Related Video
In this pregnancy video section a whole range of videos are provided to watch which cover a whole range of subjects, from general pregnancy, complications, newborn care and even beauty.

Lowermilk, D., Perry, S. (2007). Maternity & Women's Health Care. 9th Edition. Mosby/Elsevier: St Louis, Missouri.
Underwood, M. A., Gilbert, Sherman M. P. (2005). Amniotic Fluid: Not Just Fetal Urine Anymore. Journal of Perinatology. 25, 341–348. http://www.nature.com/jp/journal/v25/n5/full/7211290a.html

Artificial Rupture of Amniotic Fluid

Amniotic fluid is a clear, slightly yellowish liquid that surrounds the foetus during pregnancy. It  is contained in the amniotic sac. The purpose of the amniotic sac is to protect the foetus from infection to cushion the foetus in the womb, a medium for foetus to grow in and thrive by maintaining a constant temperature, allowing movement to aid muscle development, protecting against infection – the membranes provide a barrier- the fluid contains antimicrobial peptides, assisting lung development, baby breathes fluid in and out of the lungs, and also plays an important part in developing many of the baby's vital internal organs, such as the lungs, kidneys and gut.

At full term, there is between 500-1000 ml of amniotic fluid. This is mostly made up of amniotic fluid secreted by the amniotic sac (the membranes). The baby also contributes urine and respiratory tract secretions into the fluid. The amniotic fluid is constantly being produced and renewed – Baby swallows the fluid; it is passed through the gut into the baby’s circulation; then sent out through the placenta. This process continues even if the amniotic membranes have broken. The amniotic fluid contains substances such as albumin, urea, uric acid, creatinine, lecithin, sphingomyelin, bilirubin, fat, fructose, leukocytes, proteins, epithelial cells, enzymes, vernix and lanugo.

Unfortunately artificial rupture of membranes (AROM)has become "routine practice". It is useful if there is delay in progress. But it really has no place in normally progressing labour. Very often the membranes will rupture just before birth. In the animal kingdom the offspring are very often born in their amniotic sacs. The research indicated that it does not shorten labour by any significant amount. It is a method of inducing labour but that is another story.  In my experience, AROM usually benefits the midwife or obstetrician. It speeds things up for them, and also gives them peace of mind as they can see whether or not there is meconium in the liquor so they can get a paediatrician ready to be present at delivery. There is no indication for it in normal labour.

I was at a workshop many years ago where a midwife was giving a talk about home birth and leaving the membranes intact. After the lecture, one of the attendees was horrified that a midwife would not perform AROM as it was so dangerous not to know if there was meconium! She definitely needed a chat! Then there was the OB/GYN who commented on labour ward protocols: " there is no reason to keep membranes intact even in a labour that is going "normally," all membranes should be ruptured because they serve no pupose at all." Of course the fact that most women report more pain is neither here nor there, because there's probably no randomised control trial that proves it! That means mother nature has got it horribly wrong for the last 100,000 years and you've managed to figured it out completely in the last 100 years!

But it is not only the providers that can be the problem, birthing mothers can be just as uninformed. I  have frequently had multiparous women request AROM for relief of pressure and I often find they tend to progress very quickly post AROM - tends to bring the head down onto the cervix and enhance uterine contractions. However, a cochrane review of the available research states that “the evidence showed no shortening of the length of first stage of labour and a possible increase in caesarean section. Routine amniotomy is not recommended for normally progressing labours or in labours which have become prolonged.”

Gabbe, S. G., Simpson, J. L,  Niebyl, J. R. Galan, H., Goetzl, L. Jauniaux, E. R. M. Landon, M.  (2007). Obstetrics: Normal and Problem Pregnancies. 5th ed. Philadelphia, PA: Elsevier Churchill Livingstone. 

Smyth, R., Alldred, S. K., Markham, C. (2007). Amniotomy for shortening spontaneous labour. Cochrane Database of Systematic Reviews. Issue 4. Art. No.: CD006167.

Private or Independent Midwives in South Africa

A Registered Midwife in South Africa is someone with a diploma or degree in  nursing. Nurse midwives work in public hospitals or clinics while others work in private hosptials as obstetrics nurses not as midiwves because all births are in the hands of obstetricians. It is so sad that when deciding whether to go public or private,  a pregnant woman need to weigh up what she want out of the birthing experience, as well as what you can afford and if their medical aid cover will absorb the costs of going private.

In South Africa, there seems to be a demand for a less technological medicalised birth. There is an increase in women who are express a preference for a birth with a private midwife. In South Africa the trend back towards delivering with a private midwife is relatively recent and the field of private practicing (independent) midwives a growing one. Midwives offer the same care as any obstetrician or general practitioner who delivers babies.

It was not so long ago when the previous government forced out all private midwives out of practice. Before 1976 all black women gave birth at home in the comfort of a midwife. Unfortunately some people still frown when I tell them to plan to have their baby born naturally and at home. It would be nice if natural home birth becomes the normality, like it used to be before medicalization of birth and the takeover of birth by men. Natural birth makes you think and I don’t think many people want to think. We have to unlearn to what was normal before and to do this will take time, determination and lots of education.

As mentioned most mothers prefer to be with a private midwife, than giving birth with an obstetrician/gynecologist. The problem is there are not enough of them. We are facing a dilemma of hospital births with an expert such as an obstetrician/gynecologist or overworked, and underpaid, nurse midwives in South Africa in poor resourced facilities. We wish for more nurses to go into private practice and support the thousands of South African women, black or white who demand good care and in the comfort of their homes.

There are no statistics available of the number of babies delivered by private midwives and no register exists of the names and numbers of private midwives available. These private midwives need to be registered with the South African Nursing Council every year as a professional Midwife.  She also needs to be registered as a Private Nurse Practitioner with a practice number.

A nurse practitioner in South Africa is a nurse who has been trained in general nursing and midwifery and who has additional skills gained from additional course work. These nurses are usually experienced in a certain field in which they practice. They must be registered with the Board of Healthcare Funders of SA as a Practitioner or Agency and pay a fee  after which they will be given a practice number, which must appear, on all your stationary. This is recommended but not obligatory.

Their address:

P O Box 2324, Parklands 2121

Telephone: 011 880 8900

Indemnity insurance, although not compulsory, is a basic essential for any practitioner. The most cost effective and efficient insurance available in South Africa at present is that afforded to members of DENOSA and HOSPERSA. In addition one can take out additional insurance cover through DENOSA should you be practicing in a high-risk area such as home deliveries? Indemnity insurance is also available to members of the Occupational Health Nurses through the organisation.  

 HOSPERSA:

P O Box 12266 Queens wood 0121

Telephone 012 333 6252

DENOSA:

P O Box 1280, Pretoria 0001

Telephone: 012 343 2315 

 Licensing to prescribe and store medications are available on a limited basis through the Department of Health but there is a delay at present, while midwives planning to do home deliveries are required to register with the Local Authority for a permit. Current legislation, s38A, does not apply to nurses working in the private sector. Should South Africa consider state funding for home births as an alternative to hospital-based delivery? Midwifery services should be fully funded by the government of South Africa. This might be the answer to our overcrowded understaffed maternity units and high maternal mortality rates.

A midwife typically meets an expectant mother early in her pregnancy and sees her regularly throughout. Once labour begins, the midwife often goes to the home of the mother-to-be to check whether active labour is in progress or can also meet her patient at the hospital. The midwife attends the woman continuously during labour and delivery at the hospital. Barring any complications, the new mother can then choose to stay in the hospital or go home with her baby within hours of the birth. The midwife visits the mother and baby at home on days one, three and five and sees them at a clinic two, four and six weeks after birth. This is what birth should be like, not be controlled by surgeons, they should only take care of complications during chilbirth.

Caesarian Sections aren't always best for preterm babies

 

Doctors have long assumed that Caesarean sections might be the best choice for babies that will be born preterm. But a new study shows that C-sections are no safer than vaginal delivery for the most fragile of infants, those who are born early and who are small for their age. In fact, C-sections might actually lead to a greater risk of respiratory problems and other complications in these infants, according to a report presented at the annual meeting of the Society for Maternal-Fetal Medicine.

The new results suggest that doctors need to re-think how they look at C-sections, said the study’s lead author Dr. Erika Werner, an assistant professor of gynecology and obstetrics at the Johns Hopkins School of Medicine. “You shouldn’t assume there’s no downside to the baby with a C-section,” Werner said.

This kind of information becomes increasingly important as Caesarean deliveries become more and more common. The Centers for Disease Control and Prevention found that C-section rates rose 33 percent from 2000 to 2007, with women under the age of 25 experiencing the greatest increase at 57 percent.

“The rates of C-section are going up in the US and every other country. According to Dr Nancy of ABC “One reason may be in vitro fertilization and multiple births. One part of it, though is women trying to put delivery on their own schedules. And, you’ve heard this before: ‘too posh to push.’”

The most recent data – from 2009 – show that 45.6 percent of premature babies were delivered by Cesarean section, as compared to 35.1 percent of those born at 37-38 weeks.

Part of the explanation for the especially high rate among preemies may lie in the assumption that vaginal births might be too traumatic – and dangerous - for fragile infants who are underweight and preterm, said Dr. Diane Ashton, deputy director at the national office of the March of Dimes.

“When I was in my obstetric residency training in the late '80s, we were taught that it would be protective to do Caesarean deliveries on preterm babies because vaginal birth might put them at risk for internal hemorrhages and other complications,” Ashton said.

The push for C-sections was especially strong when it came to infants who weren’t growing fast enough in the uterus, Snyderman told TODAY’S Ann Curry Thursday. “The conventional wisdom has been to get those babies out and we’ll treat them in an ICU,” Snyderman said.

For the new study, Werner and her colleagues scrutinized the medical records of 2,560 babies born preterm between 1995 and 2003 in New York City. More than half -- 54 percent -- of the babies had been delivered through Caesarean section

Babies born vaginally were no more likely to have developed subdural hemorrhages, seizures, or sepsis than those delivered by C-section. Instead, the researchers found that babies born by C-section were 30 percent more likely to develop respiratory distress syndrome. And this may have long term fallout for the babies, Snyderman said.

“The breathing problems can turn into asthma later in life,” she explained. “In the last few weeks of pregnancy, that’s when the lungs and the brain are developing. So developmental problems, cerebral palsy, learning disability – all those things become compounded if a baby is taken out prematurely.”

One thing the researchers don’t know is why doctors chose to deliver the babies in the study via C-section. It’s possible, Werner allowed, that in some cases C-sections were chosen to speed delivery because the baby’s or the mother’s lives were at risk.

But in cases where there is no imminent danger to the baby or the mom, doctors should lean towards vaginal delivery, both Werner and Ashton said. And that’s probably true for full-term babies too, Werner said.

“I think there’s a chance that full term infants might also have lower rates of respiratory distress,” Werner said. “That’s speculation at this point. But it’s another reason for doctors to think a lot about the benefits of vaginal delivery.”

NBC's Dr. Nancy Snyderman