Obesity and pregnancy – the new taboo

The staggering increase in prevalence of obesity in the Western world has been mirrored by a similar growth in maternal obesity, making it one of the most important preventable risk factors for pregnancy. In addition, a growing swell of research indicates that maternal obesity may have long-term negative impacts on a child’s development and growth.

A recent study published in the journal Paediatrics found that maternal obesity was associated with delays in fine motor development, while another recent paper determined links between maternal weight and the risk of autism.

Closely linked to social and educational inequalities, experts are in agreement that management of this condition should be standardised, yet addressing this controversial issue in the clinic is understandably difficult due to the sensitivity of the topic.

A recent scientific paper commissioned by the European Board and College of Obstetrics and Gynaecology (EBCOG) looked at the controversies surrounding the management of obese pregnant women across Europe. The paper “Maternal obesity in Europe: Where do we stand and how to move forward?” was published last year in the European Journal of Obstetric, Gynaecologic and Reproductive Biology. It highlighted the disparity in attitudes towards the problem across Europe, and proposed an integrated, cohesive approach to tackling this issue.

According to the authors, most European countries do not systematically report obesity figures in their pregnant population, but estimates show that the prevalence of maternal obesity varies from 7 to 25%. Because  of  this  rising  incidence  of  obesity  among  women,  Euro-Peristat  have  recently  added  the monitoring of mother’s pre-pregnancy BMI [body mass index], categorised as a recommended perinatal health indicator.

“Obesity during pregnancy represents an important preventable risk factor for adverse pregnancy outcomes and is associated with negative long-term health outcomes for both mothers and offspring. These effects are often aggravated by the high incidence of abnormal glucose tolerance and excessive gestational weight gain found in this group,” explained the authors.

The authors state that maternal obesity is a “major public health concern because of the increased risks for both the mother and child”. While the increased risks for the mother of a miscarriage, metabolic and cardiovascular  dysfunctions  presented  as  gestational  diabetes  and  hypertension,  pre-eclampsia, dysfunctional labour and caesarean section have been well-established, these complications are augmented when maternal  obesity is  combined with excessive  gestational  weight gain. For the infant, there is an increased risk of congenital malformations, macrosomia and admission to a neonatal care unit; in addition, the risk of stillbirth is also strongly related to maternal weight.

The authors believe the main controversies around the management of the obese pregnant women are related to (1) the value of repeated weighing during pregnancy, (2) the optimal gestational weight gain to advise and the lifestyle messages to deliver in order to achieve this, (3) the optimal strategy and timing of screening for gestational diabetes (GDM) and (4) the optimal timing and mode of delivery.

Weighing during pregnancy is a sensitive issue. In the UK, routine weighing was phased out on recommendations of the National Institute for Health Care and Excellence (NICE) as it was potentially resulting in increased maternal stress without proven benefit. This attitude was recently supported by an Australian study in which 782 pregnant women were randomly assigned to systematic weighing during pregnancy versus routine care; it was shown that routine weighing at antenatal visits did not reduce total gestational weight gain or excessive gestational weight gain.

Yet, in contrast to this, weighing in pregnancy still forms a routine part of antenatal practice in many 175 European countries like France, Denmark, Germany, Italy and Belgium, say the authors.

From a public health perspective, there are many advantages to routine weighing and recording this in the perinatal databases. In the region of Flanders, Belgium, where patients are weighed routinely, BMI and gestational weight gain have been available for all pregnancies in the region since 2009. “This has led to a better insight in the socio-demographics of gestational weight gain and maternal obesity, the related perinatal outcomes and the effects of weight fluctuation between pregnancies,” state the authors.

The authors have now proposed an agenda for research is proposed with the hope that it will catch the attention of policy-makers and funders and ultimately lead to the development of European-wide evidence-based guidelines for clinicians.

“An  integrated  approach  for  the  management  of  obesity  in  women  of  reproductive  age  who  are planning a pregnancy is crucial. Management should begin before conception and continue through pregnancy and the postpartum period within a multidisciplinary team focusing on mental wellbeing, healthy eating and physical activity including weight management techniques.  Maternal obesity not only implies a personal responsibility but also infers a social, environmental, political and  economic responsibility.”

Also last year, a series of papers were published on this topic by a team of global medics in The Lancet Diabetes and Endocrinology. Maternal obesity is a “worrisome trend in high-risk pregnancies that could impact mother and child”, according to Dr Patrick M. Catalano, Director of the Centre for Reproductive Health at MetroHealth and Director of the Clinical Research Unit of the Case Western Reserve University. He also advocates a comprehensive integrated approach to addressing this growing problem, and this should potentially be personalised to each individual woman.

According to Dr Catalano, the management of obesity in pregnancy begins before, during and after pregnancy.

“There is limited evidence based data on how best to mitigate adverse metabolic effects of obesity on mothers and their offspring once a woman is pregnant. Basic questions as to what is the optimal diet or weight gain during pregnancy need to be addressed. In the interim, until a comprehensive potentially personalized life-course approach is instituted, efforts during pregnancy will by necessity be aimed at recognizing and mitigating the adverse metabolic consequences of maternal obesity during pregnancy on both the mother and her child.

Dr Catalano tells PMI that in places like the United States approximately 60% of women of reproductive age are either overweight or obese.

“Pregnant women who are overweight or obese are at increased risk of multiple problems including early pregnancy miscarriage and congenital anomalies.  Later in pregnancy they are at increased risk for the development of gestational diabetes and preeclampsia. At the time of delivery there is an increased risk of cesarean delivery post cesarean venous thrombophlebitis in overweight and obese women.  Additionally, 50-70% of overweight and obese women gain in excess of Institute of Medicine (IOM) gestational weight guidelines. Gestational weight gain in excess of these IOM guidelines increases the risk of postpartum weight retention,” he says.

Dr Catalano says he personally believes in the value of regular weighing during pregnancy.

“I believe that this is important since many women have a notion that pregnancy is a time for eating for two and that gaining lots of weight in pregnancy is important and good for pregnancy. My personal belief is that having weight gain in pregnancy recorded is important for women to avoid excessive weight gain,” he states, adding that it is also important for those women who are having inadequate weight gain, to help them improve their weight gain through healthy eating.

He bemoans the lack of evidenced-based guidelines, although certain expert groups do have general recommendations about obesity in pregnancy.

Dr Catalano’s team is now beginning a research programme looking at lifestyle intervention prior to a planned pregnancy to improve maternal health and outcomes for the offspring.

“The lifestyle intervention includes healthy eating and increase physical activity for women who are overweight and obese.”

Leave a comment