Care of Women with Obesity in Pregnancy

Abstract

What care should be provided in the primary care setting to women of childbearing age with obesity who wish to become pregnant? Primary care services should ensure that all women of childbearing age have the opportunity to optimise 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 optimise their weight before pregnancy. Grade of recommendation: ✓ 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. Grade of recommendation: D 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 caesarean (VBAC) section. Grade of recommendation: B What nutritional supplements should be recommended to women with obesity who wish to become pregnant? 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. Grade of recommendation: D 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. Grade of recommendation: B How and where should antenatal care be provided? Care of women with obesity in pregnancy can be integrated into all antenatal clinics, with clear local policies and guidelines for care available. Grade of recommendation: D What are the facilities, equipment, and personnel required? 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: 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. Grade of recommendation: ✓ 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 labour and birth. Clear communication of manual handling requirements should occur between the labour and theatre suites when women are in early labour. Grade of recommendation: D 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. Grade of recommendation: ✓ When and how often should maternal weight, height and BMI be measured? 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. Grade of recommendation: D 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. Grade of recommendation: ✓ What is the acceptable gestational weight gain in obese women? 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. Grade of recommendation: ✓ What are the clinical risks of maternal obesity to maternal and fetal health in pregnancy? 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 minimised. Women should be given the opportunity to discuss this information. Grade of recommendation: D What dietetic and exercise advice should be offered in pregnancy? Dietetic advice by an appropriately trained professional should be provided early in the pregnancy where possible in line with NICE Public Health Guideline 27. Grade of recommendation: ✓ What is the role of anti-obesity drugs in pregnancy? Anti-obesity or weight loss drugs are not recommended for use in pregnancy. Grade of recommendation: C What specific risk assessments are required for anaesthetics? Pregnant women with a booking BMI 40 kg/m2 or greater should be referred to an obstetric anaesthetist for consideration of antenatal assessment. Grade of recommendation: D 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. Grade of recommendation: D What specific risk assessments are required for prevention of pressure sores? 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. Grade of recommendation: D What special considerations are recommended for screening, diagnosis and management of gestational diabetes in women with obesity? 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. Grade of recommendation: B What special considerations are recommended for screening, diagnosis and management of hypertensive complications of pregnancy in women with obesity? 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. Grade of recommendation: C 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. Grade of recommendation: B 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. Grade of recommendation: B Women who develop hypertensive complications should be managed according to the NICE CG107. Grade of recommendation: ✓ What special considerations are recommended for prevention, screening, diagnosis and management of venous thromboembolism in women with obesity? 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. Grade of recommendation: B 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. Grade of recommendation: D Acute VTE in pregnant women with obesity should be treated according to RCOG GTG No. 37b . Grade of recommendation: ✓ What special considerations are recommended for screening, diagnosis and management of mental health problems in women with obesity? 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. Grade of recommendation: D There is insufficient evidence to recommend a specific lifestyle intervention to prevent depression and anxiety in obese pregnant women. Grade of recommendation:✓ What special considerations does maternal obesity have for screening for chromosomal anomalies during pregnancy? 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. Grade of recommendation: B Consider the use of transvaginal ultrasound in women in whom it is difficult to obtain nuchal translucency measurements transabdominally. Grade of recommendation: ✓ What special considerations does maternal obesity have for screening for structural anomalies during pregnancy? 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. Grade of recommendation: C How and when should the fetus be monitored antenatally? 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. Grade of recommendation: B 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. Grade of recommendation: ✓ Where external palpation is technically difficult or impossible to assess fetal presentation, ultrasound can be considered as an alternative or complementary method. Grade of recommendation: ✓ How and when should the fetus be monitored during labour? In the absence of good-quality evidence, intrapartum fetal monitoring for obese women in labour should be provided in accordance with NICE CG190 recommendations. Grade of recommendation: ✓ How and when should the fetus be monitored post dates in women with obesity? There is a lack of definitive data to recommend routine monitoring of post dates pregnancy. However, obese pregnant women should be made aware that they are at increased risk of stillbirth. Grade of recommendation: D What should be discussed with women with maternal obesity regarding labour and birth? 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. Grade of recommendation: ✓ Women who are multiparous and otherwise low risk can be offered 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. Grade of recommendation: C Active management of the third stage should be recommended to reduce the risk of postpartum haemorrhage (PPH). Grade of recommendation: A Is maternal obesity an indication for induction of labour? 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. Grade of recommendation: B Is maternal obesity an indication for caesarean section? 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. Grade of recommendation: C Is macrosomia and maternal obesity an indication for induction of labour and/or caesarean section? 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. Grade of recommendation: B What care should women with obesity and a previous caesarean section receive? 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. Grade of recommendation: ✓ Where should obese women give birth? 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. Grade of recommendation: D 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. Grade of recommendation: ✓ What lines of communication are required during labour and birth in women with maternal obesity? 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. Grade of recommendation: ✓ What midwifery support should be available during labour to obese women? 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. Grade of recommendation: ✓ What specific interventions may be required during labour and birth for women with maternal obesity? In the absence of current evidence, intrapartum care should be provided in accordance with NICE CG190. Grade of recommendation: ✓ 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. Grade of recommendation: ✓ 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. Grade of recommendation: B What specific surgical techniques are recommended for performing caesarean section on the obese woman (including incision, closure)? There is a paucity of high-quality evidence to support the use of one surgical approach over another. Surgical approaches should therefore follow NICE CG132 but clinicians may decide alternative approaches are merited depending on individual circumstances. Grade of recommendation: ✓ What postoperative wound care is recommended following caesarean section in women with obesity? 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. Grade of recommendation: A 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. Grade of recommendation: A 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. Grade of recommendation: B How can the initiation and maintenance of breastfeeding in women with maternal obesity be optimised? 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. Grade of recommendation: ✓ What ongoing care, including postnatal contraception advice, should be provided to women with maternal obesity following pregnancy? Maternal obesity should be considered when making the decision regarding the most appropriate form of postnatal contraception. Grade of recommendation: ✓ What information should be given postnatally to obese women about their long-term health risks and those of their children? 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. Grade of recommendation: D Women who have been diagnosed with gestational diabetes should have postnatal follow-up in line with NICE Guideline 3. Grade of recommendation: D What support can be given in the community to ensure minimal interpregnancy weight gain or to minimise risks of a future pregnancy? Women should be supported to lose weight postpartum and offered referral to weight management services where these are available. Grade of recommendation: ✓ What are the clinical risks of previous bariatric surgery to maternal and fetal health during pregnancy? 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. Grade of recommendation: D How should women with previous bariatric surgery be cared for during pregnancy? Women with previous bariatric surgery have high-risk pregnancies and should have consultant-led antenatal care. Grade of recommendation: ✓ Women with previous bariatric surgery should have nutritional surveillance and screening for deficiencies during pregnancy. Grade of recommendation: D Woman with previous bariatric surgery should be referred to a dietician for advice with regard to their specialised nutritional needs. Grade of recommendation: D Obesity is becoming increasingly prevalent in the UK population 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.1 According to World Health Organization criteria,2 adults can be classified according to BMI as shown below in Table 1. While the majority of the recommendations within this guideline pertain to women with a BMI 30 kg/m2 or greater, some recommendations are specific to women in the higher classes of obesity only. Obese women with a BMI below a specified threshold may also benefit from recommendations in a higher BMI group, depending on individual circumstances. However, the chosen BMI cut-offs reflect careful consideration given to the balance of medical intervention versus risk, differences in local prevalence of maternal obesity and resource implications for local healthcare organisations. The recommendations cover interventions prior to conception, and during and after pregnancy. The prevalence of obesity in the general population in the UK has increased markedly since the early 1990s. The prevalence of obesity in pregnancy has also been seen to increase, rising from 9–10% in the early 1990s to 16–19% in the 2000s.3, 4 Pregnant women who are obese are at greater risk of a variety of pregnancy-related complications compared with women of normal BMI, including pre-eclampsia and gestational diabetes. Pregnant women who are obese are also at increased risk of caesarean birth. Maternal size can make the assessment of fetal size, presentation and external monitoring of fetal heart tracing more challenging during pregnancy. Initiation and maintenance of breastfeeding are also more difficult in the women with obesity.1, 5-17 High prepregnancy BMI is associated with a small but statistically significant increase in severe maternal morbidity or mortality, with the adjusted rate difference per 10 000 women compared with normal BMI being 24.9 (95% CI 15.7–34.6) for women with class I obesity, 35.8 (95% CI 23.1–49.5) for women with class II obesity and 61.1 (95% CI 44.8–78.9) for women with class III obesity.18 These US data are supported by the 2015 MBRRACE-UK (Mothers and Babies: Reducing Risk through Audits and Confidential Enquiries across the UK) review into maternal deaths, which reported that 30% of women who died were obese and 22% were overweight.19 In recognition of the excess in deaths and additional risks, the Confidential Enquiry on Maternal and Child Health (CEMACH 2003–5) recommended that women with a BMI 30 kg/m2 or more should be seen for prepregnancy counselling. This guideline was developed using standard methodology for developing RCOG Green-top Guidelines (GTGs). The Cochrane Library (including the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects [DARE] and the Cochrane Central Register of Controlled Trials [CENTRAL]), EMBASE, MEDLINE, and Trip were searched for relevant papers. The search was inclusive of all relevant articles published until May 2016. A top-up literature search was performed in January 2018. The databases were searched using the relevant Medical Subject Headings (MeSH) terms, including all subheadings and synonyms, and this was combined with a keyword search. Search terms included ‘obesity’, ‘bariatric surgery’, ‘anti-obesity agents’, and ‘(prepregnancy or pre-pregnancy or preconception* or pre-conception* or pregestation* or pre-gestation*) adj3 (obes* or weight or bmi)’. The search was limited to studies on humans and papers in the English language. Relevant guidelines were also searched for using the same criteria in the National Guideline Clearinghouse and the National Institute for Health and Care Excellence (NICE) Evidence Search. Where possible, recommendations are based on available evidence. Areas lacking evidence are highlighted and annotated as ‘good practice points’. Further information about the assessment of evidence and the grading of recommendations can be found in Appendix I. Primary care services should ensure that all women of childbearing age have the opportunity to optimise 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 optimise their weight before pregnancy. Grade of recommendation: ✓ 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 NICE Clinical guideline (CG) 189. Grade of recommendation: D 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 caesarean (VBAC) section. Grade of recommendation: B 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. Grade of recommendation: D 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. Grade of recommendation: B The main source of vitamin D is synthesis on exposure of the skin to sunlight. However, in the UK there is limited sunlight of the appropriate wavelength, particularly during winter. A survey in the UK showed that approximately one-quarter of UK women aged between 19 and 24 years, and one-sixth of those aged between 25 and 34 years, are at risk of vitamin D deficiency.51 Maternal skin exposure alone may not always be enough to achieve the optimal vitamin D status needed for pregnancy, and the recommended oral intake of 10 micrograms vitamin D daily for all pregnant and breastfeeding women cannot usually be met from diet alone. Care of women with obesity in pregnancy can be integrated into all antenatal clinics, with clear local policies and guidelines for care available. Grade of recommendation: D 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: Grade of recommendation: ✓ 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. Grade of recommendation: ✓ Women with a booking BMI 40 kg/m2 for whom moving and handling is 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 labour and birth. Clear communication of manual handling requirements should occur between the labour and theatre suites when women are in early labour. Grade of recommendation: D 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. Grade of recommendation: ✓ 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. Grade of recommendation: D 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. Grade of recommendation: ✓ Mandatory height and weight data fields in electronic patient information systems, and functionality allowing the automatic calculation of BMI, may be useful to enable local organisations to achieve 100% compliance with this standard. 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. Grade of recommendation: ✓ 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 minimised. Women should be given the opportunity to discuss this information. Grade of recommendation: D Dietetic advice by an appropriately trained professional should be provided early in the pregnancy where possible in line with NICE Public Health Guideline 27. Grade of recommendation: ✓ Many women and their partners have pre-existing social and cultural beliefs about pregnancy diet and weight gain.67 These views should be considered when discussing the importance of healthy eating and appropriate exercise during pregnancy to prevent excessive weight gain and gestational diabetes.63 Anti-obesity or weight loss drugs are not recommended for use in pregnancy. Grade of recommendation: C Anti-obesity or weight loss drugs are used for the management of obesity in women of reproductive age. Currently, there is a paucity of information about the effect of anti-obesity drugs on the fetus and access to most anti-obesity drugs (with the exception of orlistat) is limited. Topiramate and phentermine are also individually excreted in breast milk and, therefore, the combination of phentermine/topiramate may also be present in breast milk. Treatment with either medication is therefore not recommended during lactation due to unknown risks on the infant. Pregnant women with a booking BMI 40 kg/m2 or greater should be referred to an obstetric anaesthetist for consideration of antenatal assessment. Grade of recommendation: D 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. Grade of recommendation: D 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. Grade of recommendation: D 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 (SIGN) guidelines. Grade of recommendation: B 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. Grade of recommendation: C 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. Grade of recommendation: B Women with more than one moderate risk factor (BMI of 35 kg/m2 or greater, first pregnancy, maternal ag