A randomized longitudinal dietary intervention study during pregnancy: effects on fish intake, phospholipids, and body composition

Abstract

Background: Fish and meat intake may affect gestational weight gain, body composition and serum fatty acids. We aimed to determine whether a longitudinal dietary intervention during pregnancy could increase fish intake, affect serum phospholipid fatty acids, gestational weight gain and body composition changes during pregnancy in women of normal weight participating in the Pregnancy Obesity Nutrition and Child Health study. A second aim was to study possible effects in early pregnancy of fish intake and meat intake, respectively, on serum phospholipid fatty acids, gestational weight gain, and body composition changes during pregnancy.

Methods: In this prospective, randomized controlled study, women were allocated to a control group or to a dietary counseling group that focused on increasing fish intake. Fat mass and fat-free mass were measured by air-displacement plethysmography. Reported intake of fish and meat was collected from a baseline population and from a subgroup of women who participated in each trimester of their pregnancies. Serum levels of phospholipid arachidonic acid (s-ARA), eicosapentaenoic acid (s-EPA), and docosahexaenoic acid (s-DHA) were measured during each trimester.

Results: Weekly fish intake increased only in the intervention group (n = 18) from the first to the second trimester (median difference 113 g, p = 0.03) and from the first to the third trimester (median difference 75 g, p = 0.01). In the first trimester, fish intake correlated with s-EPA (r = 0.36, p = 0.002, n = 69) and s-DHA (r = 0.34, p = 0.005, n = 69), and meat intake correlated with s-ARA (r = 0.28, p = 0.02, n = 69). Fat-free mass gain correlated with reported meat intake in the first trimester (r = 0.39, p = 0.01, n = 45).

Conclusions: Dietary counseling throughout pregnancy could help women increase their fish intake. Intake of meat in early pregnancy may increase the gain in fat-free mass during pregnancy.

Figure 1

Pregnancy obesity nutrition and child health study protocol. Recruitment process, randomization and study visit flow in the control and intervention groups. Trimester 1, pregnancy weeks 8–12; trimester 2, pregnancy weeks 24–26; trimester 3, pregnancy weeks 35–37.

Figure 2

Recruitment, randomization, participation, drop-outs, exclusion and final data analysis groups of normal weight women in the pregnancy obesity nutrition and child health study. Flow chart illustrating the number of normal weight women that were recruited, were randomized to intervention or control groups, participated in study visits, and were drop-outs. Women were excluded for miscarriage after trimester 1 (n = 2), intrauterine fetal death (n = 1), duplex pregnancy (n = 1), sudden infant death syndrome (n = 1), abortion (n = 1), and delivery before pregnancy week 34 (n = 1). For data analyses, we defined two populations: a) a pooled “early pregnancy” population at baseline and b) a subpopulation of all women who participated in all 3 trimesters.