Bring overweight or obese during pregnancy can put you at an increased risk of complications. If you are overweight, the best way to protect your health and your baby's well being is to lose weight before you become pregnant. By reaching a healthy weight, you increase your chances of conceiving naturally and reduce your risk of the problems associated with being overweight in pregnancy.

It is important to have a healthy balanced diet and moderate exercise throughout pregnancy. This will help you maintain your weight rather gaining too much. Please read the information in the staying healthy in pregnancy and weight gain section.

Many areas offer free weight management support services before, during and after pregnancy. Please ask your midwife for details in your local area.

The likelihood of you developing diabetes in pregnancy (gestational diabetes) increases with your BMI. Your midwife will arrange a screening test for diabetes for when you are 26 weeks.

Women who have a high BMI are at a higher risk of developing high blood pressure. If you develop high blood pressure in pregnancy, you may also develop a more serious condition called pre-eclampsia,which can affect the health of you and your baby. Your midwife will be assessing your health including your blood pressure at each antenatal visit.

Pregnant women are ten times more likely to develop blood clots (venous thrombosis) than women who are the same age and not pregnant. You are even more likely to develop blood clots if your BMI is above 30 at your booking appointment. You are therefore encouraged to stay well hydrated and active during pregnancy and will be advised to wear support stockings, if you are admitted to hospital.

Your midwife will assess your individual risk of developing blood clots. Women who are most at risk of developing blood clots may be prescribed additional preventative medication.

All women are offered two scans in their pregnancy. These scans check your baby’s major organs and physical characteristics. If you have a high BMI, especially with body fat around your abdomen (tummy), the ultrasound image will not be as clear. This limits your sonographer’s ability to assess your baby’s growth and development.

It is also more difficult to estimate growth or determine your baby’s position using abdominal palpation. A further scan to assess your baby’s growth or position may be necessary later in your pregnancy. Your midwife will discuss this with you.

Studies suggest that having a high BMI is associated with an increased risk of stillbirth. If your BMI is above 35 your risk of stillbirth is twice as high as the general pregnant population (8.6 per 1000 births compared to 3.9 per 1000 births). The risk of stillbirth increases with increasing BMI and the reason for this is largely unknown. It is important to become familiar with your baby’s daily pattern of movements and contact the Maternity Unit if you have any concerns or your baby’s movements are reduced.

While many women with a high BMI have straightforward births, the likelihood of complications is increased. These complications include:

  • induction of labour
  • a longer labour
  • a caesarean section
  • difficulties in hearing the baby’s heartbeat
  • larger babies and difficulties delivering the baby’s shoulders
  • heavy bleeding after the baby is born
  • problems having epidurals and drips inserted
  • less chance of having a successful vaginal birth after a previous caesarean section

Please discuss place of birth with your midwife.

Anaesthetic procedures such as an epidural and general anaesthetic become more difficult with a high BMI, you maybe referred to see an Anaesthetist antenatally to discuss this and other pain relief option for you.

Breastfeeding has many benefits for you and your baby. It can also help you with weight loss. Find out as much as you can about breastfeeding before you have your baby. You will feel more confident when you start breastfeeding your baby if you have prepared beforehand. Your preparations may include:

  • reading the tips for successful breastfeeding in the ‘Off to the Best Start’ booklet which is available to download from the Unicef website by clicking here.