A vaginal birth after caesarean (known as a VBAC) is when a woman who has had a caesarean has a vaginal birth down the track.

In Australia, about 12% of women have a vaginal birth for a subsequent baby after a caesarean. A VBAC is much more common in some other countries, including in several Scandinavian ones, where 45-55% of women have one.

So what’s involved? What are the risks? And who’s most likely to give birth vaginally the next time round?

What happens? What are the risks?

When a woman chooses a VBAC she is cared for much like she would during a planned vaginal birth.

However, an induction of labour is avoided as much as possible, due to the slightly increased risk of the caesarean scar opening up (known as uterine rupture). This is because the medication used in inductions can stimulate strong contractions that put a greater strain on the scar.

In fact, one of the main reasons women may be recommended to have a repeat caesarean over a vaginal birth is due to an increased chance of her caesarean scar rupturing.

This is when layers of the uterus (womb) separate and an emergency caesarean is needed to deliver the baby and repair the uterus.

Uterine rupture is rare. It occurs in about 0.2-0.7% of women with a history of a previous caesarean. A uterine rupture can also happen without a previous caesarean, but this is even rarer.

However, uterine rupture is a medical emergency. A large European study found 13% of babies died after a uterine rupture and 10% of women needed to have their uterus removed.

The risk of uterine rupture increases if women have what’s known as complicated or classical caesarean scars, and for women who have had more than two previous caesareans.

Most care providers recommend you avoid getting pregnant again for around 12 months after a caesarean, to allow full healing of the scar and to reduce the risk of the scar rupturing.

National guidelines recommend women attempt a VBAC in hospital in case emergency care is needed after uterine rupture.

During a VBAC, recommendations are for closer monitoring of the baby’s heart rate and vigilance for abnormal pain that could indicate a rupture is happening.

If labour is not progressing, a caesarean would then usually be advised.

Why avoid multiple caesareans?

There are also risks with repeat caesareans. These include slower recovery, increased risks of the placenta growing abnormally in subsequent pregnancies (placenta accreta), or low in front of the cervix (placenta praevia), and being readmitted to hospital for infection.

Women reported birth trauma and post-traumatic stress more commonly after a caesarean than a vaginal birth, especially if the caesarean was not planned.

Women who had a traumatic caesarean or disrespectful care in their previous birth may choose a VBAC to prevent re-traumatisation and to try to regain control over their birth.

We looked at what happened to women

The most common reason for a caesarean section in Australia is a repeat caesarean. Our new research looked at what this means for VBAC.

We analysed data about 172,000 low-risk women who gave birth for the first time in New South Wales between 2001 and 2016.

We found women who had an initial spontaneous vaginal birth had a 91.3% chance of having subsequent vaginal births. However, if they had a caesarean, their probability of having a VBAC was 4.6% after an elective caesarean and 9% after an emergency one.

We also confirmed what national data and previous studies have shown – there are lower VBAC rates (meaning higher rates of repeat caesareans) in private hospitals compared to public hospitals.

We found the probability of subsequent elective caesarean births was higher in private hospitals (84.9%) compared to public hospitals (76.9%).

Our study did not specifically address why this might be the case. However, we know that in private hospitals women access private obstetric care and experience higher caesarean rates overall.

What increases the chance of success?

When women plan a VBAC there is a 60-80% chance of having a vaginal birth in the next birth.

The success rates are higher for women who are younger, have a lower body mass index, have had a previous vaginal birth, give birth in a home-like environment or with midwife-led care.

For instance, an Australian study found women who accessed continuity of care with a midwife were more likely to have a successful VBAC compared to having no continuity of care and seeing different care providers each time.

An Australian national survey we conducted found having continuity of care with a midwife when planning a VBAC can increase women’s sense of control and confidence, increase their chance to be upright and active in labour and result in a better relationship with their health-care provider.

Why is this important?

With the rise of caesareans globally, including in Australia, it is more important than ever to value vaginal birth and support women to have a VBAC if this is what they choose.

Our research is also a reminder that how a woman gives birth the first time greatly influences how she gives birth after that. For too many women, this can lead to multiple caesareans, not all of them needed.

Hannah Dahlen, Professor of Midwifery, Associate Dean Research and HDR, Midwifery Discipline Leader, Western Sydney University; Hazel Keedle, Senior Lecturer of Midwifery, Western Sydney University, and Lilian Peters, Adjunct Research Fellow, Western Sydney University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Vitamin D is essential for bone health, immune function and overall wellbeing. And it becomes even more crucial as we age.

New guidelines from the international Endocrine Society recommend people aged 75 and over should consider taking vitamin D supplements.

But why is vitamin D so important for older adults? And how much should they take?

Young people get most vitamin D from the sun

In Australia, it is possible for most people under 75 to get enough vitamin D from the sun throughout the year. For those who live in the top half of Australia – and for all of us during summer – we only need to have skin exposed to the sun for a few minutes on most days.

The body can only produce a certain amount of vitamin D at a time. So staying in the sun any longer than needed is not going to help increase your vitamin D levels, while it will increase your risk of skin cancer.

But it’s difficult for people aged over 75 to get enough vitamin D from a few minutes of sunshine, so the Endocrine Society recommends people get 800 IU (international units) of vitamin D a day from food or supplements.

Why you need more as you age

This is higher than the recommendation for younger adults, reflecting the increased needs and reduced ability of older bodies to produce and absorb vitamin D.

Overall, older adults also tend to have less exposure to sunlight, which is the primary source of natural vitamin D production. Older adults may spend more time indoors and wear more clothing when outdoors.

As we age, our skin also becomes less efficient at synthesising vitamin D from sunlight.

The kidneys and the liver, which help convert vitamin D into its active form, also lose some of their efficiency with age. This makes it harder for the body to maintain adequate levels of the vitamin.

All of this combined means older adults need more vitamin D.

Deficiency is common in older adults

Despite their higher needs for vitamin D, people over 75 may not get enough of it.

Studies have shown one in five older adults in Australia have vitamin D deficiency.

In higher-latitude parts of the world, such as the United Kingdom, almost half don’t reach sufficient levels.

This increased risk of deficiency is partly due to lifestyle factors, such as spending less time outdoors and insufficient dietary intakes of vitamin D.

It’s difficult to get enough vitamin D from food alone. Oily fish, eggs and some mushrooms are good sources of vitamin D, but few other foods contain much of the vitamin. While foods can be fortified with the vitamin D (margarine, some milk and cereals), these may not be readily available or be consumed in sufficient amounts to make a difference.

In some countries such as the United States, most of the dietary vitamin D comes from fortified products. However, in Australia, dietary intakes of vitamin D are typically very low because only a few foods are fortified with it.

Why vitamin D is so important as we age

Vitamin D helps the body absorb calcium, which is essential for maintaining bone density and strength. As we age, our bones become more fragile, increasing the risk of fractures and conditions like osteoporosis.

Keeping bones healthy is crucial. Studies have shown older people hospitalised with hip fractures are 3.5 times more likely to die in the next 12 months compared to people who aren’t injured.

Vitamin D may also help lower the risk of respiratory infections, which can be more serious in this age group.

There is also emerging evidence for other potential benefits, including better brain health. However, this requires more research.

According to the society’s systematic review, which summarises evidence from randomised controlled trials of vitamin D supplementation in humans, there is moderate evidence to suggest vitamin D supplementation can lower the risk of premature death.

The society estimates supplements can prevent six deaths per 1,000 people. When considering the uncertainty in the available evidence, the actual number could range from as many as 11 fewer deaths to no benefit at all.

Should we get our vitamin D levels tested?

The Endocrine Society’s guidelines suggest routine blood tests to measure vitamin D levels are not necessary for most healthy people over 75.

There is no clear evidence that regular testing provides significant benefits, unless the person has a specific medical condition that affects vitamin D metabolism, such as kidney disease or certain bone disorders.

Routine testing can also be expensive and inconvenient.

In most cases, the recommended approach to over-75s is to consider a daily supplement, without the need for testing.

You can also try to boost your vitamin D by adding fortified foods to your diet, which might lower the dose you need from supplementation.

Even if you’re getting a few minutes of sunlight a day, a daily vitamin D is still recommended.

Elina Hypponen, Professor of Nutritional and Genetic Epidemiology, University of South Australia and Joshua Sutherland, PhD Candidate – Nutrition and Genetic Epidemiology, University of South Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.