Management of Obesity in Pregnancy : RCOG Updated Guideline

Royal College of Gynaecology, RCOG has released its updated guideline on Care of Women with Obesity in Pregnancy which has appeared in British Journal of Gynaecology. This is the second edition of this guideline. The first edition was published in 2010 as a joint guideline with the Centre of Maternal and Child Enquiries under the title ‘Management of Women with Obesity in Pregnancy’.

Obesity is becoming increasingly prevalent globally and has become one of the most commonly occurring risk factors in obstetric practice, with 21.3% of the antenatal population being obese and fewer than one‐half of pregnant women (47.3%) having a body mass index (BMI) within the normal range.

Following are the major recommendations:

Prepregnancy care

• Primary care services should ensure that all women of childbearing age have the opportunity to optimize their weight before pregnancy. Advice on weight and lifestyle should be given during preconception counselling or contraceptive consultations. Weight and BMI should be measured to encourage women to optimize their weight before pregnancy.


• Women of childbearing age with a BMI 30 kg/m² or greater should receive information and advice about the risks of obesity during pregnancy and childbirth and be supported to lose weight before conception and between pregnancies in line with National Institute for Health and Care Excellence (NICE) Clinical guideline (CG) 189.


• Women should be informed that weight loss between pregnancies reduces the risk of stillbirth, hypertensive complications and fetal macrosomia. Weight loss increases the chances of successful vaginal birth after cesarean (VBAC) section.


• Women with a BMI 30 kg/m² or greater wishing to become pregnant should be advised to take 5 mg folic acid supplementation daily, starting at least 1 month before conception and continuing during the first trimester of pregnancy.


• Obese women are at high risk of vitamin D deficiency. However, although vitamin D supplementation may ensure that women are vitamin D replete, the evidence on whether routine vitamin D should be given to improve maternal and offspring outcomes remains uncertain.

Provision of antenatal care

• Care of women with obesity in pregnancy can be integrated into all antenatal clinics, with clear local policies and guidelines for care available.


• All maternity units should have a documented environmental risk assessment regarding the availability of facilities to care for pregnant women with a booking BMI 30 kg/m² or greater. This risk assessment should address the following issues: circulation space, accessibility, including doorway widths and thresholds,safe working loads of equipment and floors, appropriate theatre gowns, equipment storage, transportation, staffing levels

• availability of, and procurement process for, specific equipment, including large blood pressure cuffs, appropriately sized compression stockings and pneumatic compression devices, sit‐on weighing scale, large chairs without arms, large wheelchairs, ultrasound scan couches, ward and delivery beds, mattresses, theatre trolleys, operating theatre tables and lifting and lateral transfer equipment.


• Maternity units should have a central list of all facilities and equipment required to provide safe care to pregnant women with a booking BMI 30 kg/m² or greater. The list should include details of safe working loads, product dimensions, as well as where specific equipment is located and how to access it.


• Women with a booking BMI 40 kg/m² for whom moving and handling are likely to prove unusually difficult should have a moving and handling risk assessment carried out in the third trimester of pregnancy to determine any requirements for labor and birth. Clear communication of manual handling requirements should occur between the labor and theatre suites when women are in early labor.


• Some women with a booking BMI less than 40 kg/m² or greater may also benefit from assessment of moving and handling requirements in the third trimester. This should be decided on an individual basis.

• All pregnant women should have their weight and height measured using appropriate equipment, and their BMI calculated at the antenatal booking visit. Measurements should be recorded in the handheld notes and electronic patient information system.


• For women with obesity in pregnancy, consideration should be given to reweighing women during the third trimester to allow appropriate plans to be made for equipment and personnel required during labour and birth.


• There is a lack of consensus on optimal gestational weight gain. Until further evidence is available, a focus on a healthy diet may be more applicable than prescribed weight gain targets.

• All pregnant women with a booking BMI 30 kg/m² or greater should be provided with accurate and accessible information about the risks associated with obesity in pregnancy and how they may be minimized. Women should be given the opportunity to discuss this information.


• Dietetic advice by an appropriately trained professional should be provided early in the pregnancy where possible in line with NICE Public Health Guideline 27.


• Anti‐obesity or weight loss drugs are not recommended for use in pregnancy.

Risk assessment during pregnancy in women with obesity

• Pregnant women with a booking BMI 40 kg/m² or greater should be referred to an obstetric anaesthetist for consideration of antenatal assessment.


• Difficulties with venous access and regional and general anaesthesia should be assessed. In addition, an anaesthetic management plan for labour and birth should be discussed and documented. Multidisciplinary discussion and planning should occur where significant potential difficulties are identified.


• Women with a booking BMI 40 kg/m² or greater should have a documented risk assessment in the third trimester of pregnancy by an appropriately qualified professional to consider tissue viability issues. This should involve the use of a validated scale to support clinical judgement.

• All pregnant women with a booking BMI 30 kg/m² or greater should be screened for gestational diabetes according to NICE or Scottish Intercollegiate Guidelines Network guidelines.


• An appropriate size of cuff should be used for blood pressure measurements taken at the booking visit and all subsequent antenatal consultations. The cuff size used should be documented in the medical records.


• Clinicians should be aware that women with class II obesity and greater have an increased risk of pre‐eclampsia compared with those with a normal BMI.


• Women with more than one moderate risk factor (BMI of 35 kg/m² or greater, first pregnancy, maternal age of more than 40 years, family history of pre‐eclampsia and multiple pregnancy) may benefit from taking 150 mg aspirin daily from 12 weeks of gestation until birth of the baby.


• Women who develop hypertensive complications should be managed according to the NICE CG107.


• Clinicians should be aware that women with a BMI 30 kg/m² or greater, prepregnancy or at booking, have a pre‐existing risk factor for developing venous thromboembolism (VTE) during pregnancy.


• Risk assessment should be individually discussed, assessed and documented at the first antenatal visit, during pregnancy (if admitted or develop intercurrent problems), intrapartum and postpartum. Antenatal and post‐birth thromboprophylaxis should be considered in accordance with the RCOG GTG No. 37a.


• Acute VTE in pregnant women with obesity should be treated according to RCOG GTG No. 37b.


• Women with BMI 30 kg/m² or greater are at increased risk of mental health problems and should therefore be screened for these in pregnancy.


• There is insufficient evidence to recommend a specific lifestyle intervention to prevent depression and anxiety in obese pregnant women.

Antenatal screening

• All women should be offered antenatal screening for chromosomal anomalies. Women should be counselled, however, that some forms of screening for chromosomal anomalies are slightly less effective with a raised BMI.


• Consider the use of transvaginal ultrasound in women in whom it is difficult to obtain nuchal translucency measurements transabdominally.


• Screening and diagnostic tests for structural anomalies, despite their limitations in the obese population, should be offered. However, women should be counselled that all forms of screening for structural anomalies are more limited in obese pregnant women.

Fetal surveillance

• As recommended by RCOG GTG No. 31, serial measurement of symphysis fundal height (SFH) is recommended at each antenatal appointment from 24 weeks of gestation as this improves the prediction of a small‐for‐gestational‐age fetus.


• Women with a BMI greater than 35 kg/m² are more likely to have inaccurate SFH measurements and should be referred for serial assessment of fetal size using ultrasound.


• Where external palpation is technically difficult or impossible to assess fetal presentation, ultrasound can be considered as an alternative or complementary method.


• In the absence of good‐quality evidence, intrapartum fetal monitoring for obese women in labour should be provided in accordance with NICE CG190 recommendations.


• There is a lack of definitive data to recommend routine monitoring of postdates pregnancy. However, obese pregnant women should be made aware that they are at increased risk of stillbirth.

• Women with maternal obesity should have an informed discussion with their obstetrician and anaesthetist (if clinically indicated) about a plan for labour and birth which should be documented in their antenatal notes.


• Women who are multiparous and otherwise low risk can be offered a choice of setting for planning their birth in midwifery‐led units (MLUs), with clear referral pathways for early recourse to consultant‐led units (CLUs) if complications arise.


• Active management of the third stage should be recommended to reduce the risk of postpartum haemorrhage (PPH).


• Elective induction of labour at term in obese women may reduce the chance of caesarean birth without increasing the risk of adverse outcomes; the option of induction should be discussed with each woman on an individual basis.


• The decision for a woman with maternal obesity to give birth by planned caesarean section should involve a multidisciplinary approach, taking into consideration the individual woman's comorbidities, antenatal complications and wishes.


• Where macrosomia is suspected, induction of labour may be considered. Parents should have a discussion about the options of induction of labour and expectant management.


• Women with a booking BMI 30 kg/m² or greater should have an individualised decision for VBAC following informed discussion and consideration of all relevant clinical factors.

• Class I and II maternal obesity is not a reason in itself for advising birth within a CLU, but indicates that further consideration of birth setting may be required.


• The additional intrapartum risks of maternal obesity and the additional care that can be provided in a CLU should be discussed with the woman so that she can make an informed choice about planned place of birth.


• The on‐duty anaesthetist covering the labour ward should be informed of all women with class III obesity admitted to the labour ward for birth. This communication should be documented by the attending midwife in the notes.


• Women with class III obesity who are in established labour should receive continuous midwifery care, with consideration of additional measures to prevent pressure sores and monitor the fetal condition.


• In the absence of current evidence, intrapartum care should be provided in accordance with NICE CG190.


• Women with a BMI 40 kg/m² or greater should have venous access established early in labour and consideration should be given to the siting of a second cannula.


• Although active management of the third stage of labour is advised for all women, the increased risk of PPH in those with a BMI greater than 30 kg/m² makes this even more important.


• Women with class 1 obesity or greater having a caesarean section are at increased risk of wound infection and should receive prophylactic antibiotics at the time of surgery.


• Women undergoing caesarean section who have more than 2 cm subcutaneous fat should have suturing of the subcutaneous tissue space in order to reduce the risk of wound infection and wound separation.


• There is a lack of good‐quality evidence to recommend the routine use of negative pressure dressing therapy, barrier retractors and insertion of subcutaneous drains to reduce the risk of wound infection in obese women requiring caesarean sections.

Postnatal care and follow‐up after pregnancy

• Obesity is associated with low breastfeeding initiation and maintenance rates. Women with a booking BMI 30 kg/m² or greater should receive appropriate specialist advice and support antenatally and postnatally regarding the benefits, initiation and maintenance of breastfeeding.


• Maternal obesity should be considered when making the decision regarding the most appropriate form of postnatal contraception


• Refer to NICE CG189. Women with class I obesity or greater at booking should continue to be offered nutritional advice following childbirth from an appropriately trained professional, with a view to weight reduction in line with NICE Public Health Guideline 27.


• Women who have been diagnosed with gestational diabetes should have a postnatal follow‐up in line with NICE Guideline 3.


• Women should be supported to lose weight postpartum and offered referral to weight management services where these are available.

Management of pregnancy following bariatric surgery

• A minimum waiting period of 12–18 months after bariatric surgery is recommended before attempting pregnancy to allow stabilisation of body weight and to allow the correct identification and treatment of any possible nutritional deficiencies that may not be evident during the first months.


• Women with previous bariatric surgery have high‐risk pregnancies and should have consultant‐led antenatal care.


• Women with previous bariatric surgery should have nutritional surveillance and screening for deficiencies during pregnancy.


• Woman with previous bariatric surgery should be referred to a dietician for advice with regard to their specialised nutritional needs.