Maternal weight and the obesogenic environment in Nova Scotia

Sara Kirk, Louise Parker, Trevor Dummer, Linda Dodds, Tarra Penney

“…today’s principal neglected public health problem...” (WHO, 1997)

“…one of the most important medical and public health problems of our time..." (Prof. Philip James, IOTF

Chairman) “…given the prevalence of childhood obesity, and

given its contribution to many diseases, this is the first generation that may not live as long as their parents…” (Dr. Kellie Leitch)

The obesity time bomb

Obesity rates, by province and sex, 2004

Overweight and obesity rates: children and youth, by province, 2004

So, what happened?

www.foresight.gov.uk

Pregnancy and post-partum: an ideal time for intervention

• Obese mothers are at a high risk for many complications

• Children with obese parents are themselves more likely to be obese as adults

• Supportive programming for mothers is key to obesity prevention

• No national surveillance system that routinely measures pregnancy weight in Canada

• Canadian Perinatal Surveillance system (CPSS) collects 27 health outcomes but not BMI of the mother

The pregnant population in Canada

• Provincial level population-based, computerized database with information on pregnancy outcomes

• Maternal/newborn data available for every pregnancy of > 20 weeks gestation, with a birth weight of 500g or more

• Data on self-reported pre-pregnancy weights from 1988

The Atlee Perinatal Database

• To describe the temporal, socio-economic and demographic trends in normal weight and obese pregnant women in Nova Scotia

• Part of a larger study investigating the influence of the obesogenic environment on maternal body weight

Objective

• Self-reported pre-pregnancy weights on women in NS (1988-2006)• 172,373 deliveries (2108 multiple births)• normal weight = 55-75 kg• moderately obese = 90-120 kg• severely obese > 120 kg

• Analyses to look at trends in maternal body weight by: • Time• Age• Parity• SES• Urban/rural

Methods

Non obese

(55-75kg)

n=94,655

Moderately obese

(90-120kg) n=12,882

p Severely Obese (>120kg)

n=1,216

p

Maternal age (yrs, mean, SD)

28.5 (5.4) 28.6 (4.9) <0.001 29.2 (4.8) <0.001

Primiparous (n,%) 42,715 (45.1) 5,359 (41.8) <0.001 500 (41.1) <0.01

Low SES (n,%) 18,653 (20.3) 3,089 (24.8) <0.001 323 (27.2) <0.001

Rural (n,%) 35,193 (37.2) 5271 (41.1) <0.001 502 (41.3) <0.01

Weight gain (kg, mean SD)

15.4 (6.0) 11.5 (6.7) <0.001 9.7 (6.8) <0.001

Subject characteristics

Variation in maternal bodyweight over time, 1988-2006

52.0

54.0

56.0

58.0

60.0

62.0

64.0

66.0

68.0

70.0

72.0

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

Year

Bo

dyw

eig

ht

(kg

)

mean

median

8.6 kg increase

Percentage of women in obese category (>=90 kg)

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

Year

%

Percentage

Number of deliveries to severely obese women, 1988-2006

0

20

40

60

80

100

120

140

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

Year

Num

ber

of d

eliv

erie

s Number of deliveries to women with pre-

pregnancy weight >120kg

Maternal obesity: A provincial problem

Summary of results

• Obese women:• were slightly older• were of lower SES• gained less weight during

pregnancy• were more likely to live in rural

areas

Conclusions

• Maternal weights have increased dramatically over the last 20 years in Nova Scotia

• Deliveries in severely obese women have more than tripled since 1988

• These trends have implications for population health and health care delivery• Maternal and child health• Staffing• Resources

What next?

• In-depth exploration of the influence of the obesogenic environment on maternal body weight

• Investigation of maternal obesity in the context of the child

• Recommendations for family-centred management and prevention

Acknowledgements

• IWK Health Centre funding (Tarra Penney and Trevor Dummer)

• Reproductive Care Program of Nova Scotia (data access)