Improving pregnancy outcomes: 5 key study findings

Research is crucial to making improvements in healthcare during and after a pregnancy. 

It can help women make informed decisions about their pregnancy care. This includes identifying treatments to keep both mother and baby safe from infection. New technology, such as artificial intelligence (AI) also has a role to play in improving pregnancy outcomes. 

Here are 5 key findings from studies funded and supported by the National Institute for Health and Care Research (NIHR):

1. IVF success could be increased using AI tools

Infertility affects 1 in 7 couples in the UK, often leading them to seek in-vitro fertilisation (IVF) treatment to conceive. This involves fertilising eggs with sperm in a lab and transferring the resulting embryos to the uterus. 

During IVF treatment, doctors use ultrasound scans to monitor the size of follicles. These are the small sacs in the ovaries containing eggs. The ultrasound scans of follicles help doctors decide when to give a hormone injection. This prepares the eggs for collection and ensures they are ready to be fertilised. 

The timing of the injection is crucial, as it is less effective if the follicles are too small or too large. 

A study of over 19,000 IVF patients used AI to identify the follicle sizes most likely to result in successful births. 

The study’s findings suggest that the trigger injection should be administered when the majority of follicles are between 13 to 18mm. This differs from current practice, where clinicians administer the injection when just 2 or 3 follicles exceed 17mm. 

Researchers now plan to create an AI tool that will utilise their findings to personalise IVF treatment. The tool could help clinicians improve success rates of fertilisation. 

2. COVID-19 vaccine during pregnancy reduces risks to mother and baby

Pregnant women face a higher risk of severe COVID-19 than non-pregnant women of similar age. 

Research has shown that COVID-19 vaccines reduce death and illness severity. However, most studies excluded pregnant women. Information was therefore lacking on the safety and effectiveness of these vaccines during pregnancy.

Researchers analysed global studies published between 2019 and 2023. They compared outcomes among those who received the vaccine with those who did not.

The babies of vaccinated women were also 8% less likely to be admitted to neonatal intensive care units. 

3. Antibiotics after assisted birth halves the rate of infection

Infections are one of the leading causes of death among pregnant and recently pregnant women. Sepsis is especially common after operative vaginal births (using forceps or suction), affecting up to 16% of women.

The ANODE study looked at whether a single dose of antibiotic after operative vaginal birth could reduce infections in the 6 weeks after giving birth. The study recruited nearly 3,500 women from 27 obstetric hospital units across England and Wales. Participants were given either an antibiotic injection or a dose of saline shortly after delivery, to compare the 2. 

Results showed antibiotic use nearly halved the number of infections. Only 11% developed an infection in the antibiotic group, compared with 19% in the saline group. 

Antibiotics could prevent more than 7,000 UK infections each year. Other benefits include reduced pain, fewer wound breakdowns and fewer visits to health professionals. This would also save the NHS £52.60 per patient. 

4. Water births do not increase risks for mother or baby

The National Institute for Health and Care Excellence (NICE) recommends birthing pools as a pain relief option during labour for women without pregnancy complications. Some women leave the water before birth, others give birth in the pool.

Some healthcare professionals remain reluctant to promote water births due to potential risks. These can include infections, newborn babies inhaling water and perineal tears (from vagina to anus). However, there is little evidence to suggest water births increase these risks. 

Researchers analysed data on 60,402 women who used a birthing pool. 39,627 gave birth in the water and 20,775 gave birth out of the water. 

These findings could reassure women and healthcare professionals about the safety of water births. 

5. Earlier delivery can help women give birth to larger babies safely

At birth, large babies are at risk of shoulder dystocia, a complication where the baby becomes stuck as a shoulder is caught under the mother’s pelvic bone. This can lead to complications for babies, including fractures, nerve damage and brain injuries.

Standard screening for big babies in the UK is an important part of antenatal care. Large babies are defined as those who weigh more than 90% of other babies the same age.

The Big Baby Trial involved 2,893 women in 106 hospitals across Britain. They were randomly allocated to induction of labour up to 10 days early or standard care.

The trial showed that delivery by 7 to 10 days earlier reduced the risk of shoulder dystocia. It also reduced the need for an emergency caesarean section. 

Join a pregnancy study:

Interested in getting involved? Here are just a few studies taking place across the UK. You might be eligible to join if you are, or have recently been, pregnant:

• The POPPY study (Women's Health) (Open until July 2026)
• Improving epilepsy and pregnancy care (open until December 2026)
• Smoking, Nicotine and Pregnancy 3 trial (open until July 2026)
• Cardiometabolic Health in First Time Pregnancy (open until December 2027)
• Black parents' experiences of genetic testing in pregnancy (open until July 2026)
• Study of Ultomiris® (Ravulizumab) Safety in Pregnancy (open until 2034)

Use our study search tool to find a study that interests you.  

How you can get involved with research

Sign up to Be Part of Research to be contacted about a range of health and care research. 

And if taking part in a study doesn’t feel right at the moment, there are other ways to get involved in research.