Clinical and epidemiological aspects of obesity during pregnancy and the puerperium

Abstract

Objective: To study different aspects of obesity during pregnancy, birth and the puerperium. Paper I is an intervention study of obese pregnant women. Paper II compares fatty acid (FA) patterns in breast milk and neonates ́ plasma phospholipids in normal-weight mothers and an intervention group of obese mothers. Paper III reports the risk of obstetric anal sphincter lacerations in relation to maternal obesity among primiparas. Paper IV compares health care consumption and sick-listing among obese and normal-weight pregnant women.

Methods: Paper I is a pilot clinical study of women with BMI ≥ 30, included during a first-trimester prenatal visit. Twenty-five pregnant women were included in the intervention program, comprising visits to midwife, obstetrician and dietician, as well as weekly water gymnastics. Paper II is a randomized observational study of 41 obese and 41 normal-weight pregnant women. Twenty-nine obese women participating in a weight reduction program were included for comparison. FA were analyzed with capillary gas chromatography of lipids in breast milk collected at three and 10 days and one and two months postnatally, as well as in infants’ plasma sampled three days after birth. Paper III is a nationwide register-based study including 210,678 primiparas who gave vaginal birth to a singleton, identified from the Swedish Medical Birth Register between January 1, 2003 and December 31, 2008. Body Mass Index (BMI) was categorized into four classes, according to World Health Organization (WHO) guidelines. Paper IV is a nationwide register-based study of 108,103 pregnant women, identified from the Swedish Medical Birth Register, the Maternal Health Care Register and the Swedish National Inpatient Register between January 1, 2003 and December 31, 2008. The women were categorized into four BMI classes, according to WHO guidelines.

Results: Paper I. Fourteen (56 %) of the women had a gestational weight gain of ≤ 6 kg (study goal). There were no cases of gestational diabetes. Three (12 %) women had mild hypertension. Three women (12 %) were delivered by emergency cesarean section. All babies were healthy and had normal birth weights. Paper II. The concentrations of omega-3 FA were lower and the omega-6 / omega-3 ratio was higher in neonates and in consecutive samples of breast milk from obese mothers, compared to normal-weight mothers. FA patterns were more similar to those in normal-weight mothers when obese mothers participated in an intervention program with dietary advice and physical activity. Paper III. In multivariate analyses, increasing BMI showed a nearly dose-response-type protective effect against grade III-IV sphincter lacerations. Paper IV. Obese women made more visits to midwives, doctors and the specialized antenatal care unit. They also complained of fear of childbirth more often. They had longer in-hospital stays and were sick-listed more often during pregnancy.

Conclusions: Obese pregnant women use more healthcare recourses during pregnancy. During delivery the risk for anal sphincter lacerations decreases with higher BMI. There might be an effect at eating and exercise habits with intervention and the results suggest the importance of health promoting guidance of obese pregnant women also influencing the early fatty acids pattern of their infants.