Carlson 2013.

Methods	RCT: NCT00266825 (KUDOS)
Participants	350 women randomised Inclusion criteria: women who were English speaking, between 8 and 20 weeks of gestation, between 16 and 35.99 years of age, and planning to give birth at a hospital in the Kansas City metropolitan area Exclusion criteria: carrying more than 1 fetus, had pre‐existing diabetes mellitus or SBP ≥ 140 mmHg at enrolment, or had any serious health condition likely to affect the prenatal or postnatal growth and development of their offspring, including cancer, lupus, hepatitis, HIV/AIDS, or a diagnosed alcohol or chemical dependency, BMI ≥ 40 (self‐reported); taking DHA supplement 300 mg or more/day Characteristics: baseline DHA status mean 4.3 [1] g/100 g total fatty acids; 42% women enrolled in KUDOS were African‐American which is higher than the national average of 16% Setting: Kansas City metropolitan area, KS, USA. Study conducted from January 2006 and October 2011.
Interventions	SUPPLEMENTATION: omega‐3 (DHA) versus placebo Group 1: 600 mg DHA/day: 3 capsules/day of a marine algae‐oil source of DHA (200 mg DHA/capsule) DHASCO; n = 178 Group 2: placebo: 3 capsules containing half soybean and half corn oil. The placebo capsules did not contain DHA but did contain a‐linolenic acid; n = 172. Timing of supplementation: < 20 weeks (˜14 weeks GA) until birth DHA + EPA dose/day: mid: 600 mg DHA + EPA negligible
Outcomes	Women/birth: adherence; DHA concentrations (maternal and cord blood); DHA concentrations (by FADS genotypes in a subset of 250 women); length of gestation; miscarriage; severe PE; gestational diabetes; caesarean section; maternal adverse effects; PPH; placental abruption; preterm birth < 37 weeks; early preterm birth < 34 weeks; low birthweight; very low birthweight; antenatal hospital admission; PPROM; GWG, costs. Babies/infants/children: birthweight; birth length; head circumference at birth; ponderal index; NICU admissions, length of hospital stay; mortality; congenital anomalies; visual habituation at 4, 6 and 9 months; and at 5 years, fat mass; fat‐free mass; body fat; weight; height, BMI Z‐score
Notes	Adherence: "Capsule compliance was similar for the 2 groups: placebo (76% consumed) and DHA (78% consumed)”. Funding: NIH (R01 HD047315) and the Office of Dietary Supplements; Kansas Intellectual and Developmental Disabilities Research Center (P30 HD02528). DSM Nutritional Products (formerly Martek Biosciences) donated the placebo and DHA capsules. Declarations of interest: "SEC has given talks for several companies, including Martek, Mead Johnson Nutrition, and Nestle on results from our studies and the results of others who study the effects of DHA on infant and child outcomes. She is the President of the International Society for the Study of Fatty Acids and Lipids, which has corporate members who produce sources of DHA. JC consults with several companies on developmental measures to assess cognitive development of infants and children. None of the other authors declared a potential conflict of interest.”
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The study biostatistician generated randomization schedules for 2 maternal age groups (16–25.99 and 26–35.99 y), and each sequence of 8 random numbers included 4 assignments per group to stratify by age and treatment”
Allocation concealment (selection bias)	Low risk	Quote: “The Investigational Pharmacy personnel assigned women to placebo or DHA based on the age shared by the study personnel”
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: “Participants and data collectors were blinded to allocation, as were all investigators until children were 18 mo of age and had completed early cognitive and visual acuity development testing”
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: “Participants and data collectors were blinded to allocation, as were all investigators until children were 18 mo of age and had completed early cognitive and visual acuity development testing”
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	24/178 (13.5%) lost from DHA group: 9 changed hospitals/clinics 4 moved from city 4 miscarried 1 voluntary abortion 1 incarcerated 2 no longer interested 2 illness 1 wanted to take DHA 25/172 (14.5%) lost from placebo group: 7 changed hospitals/clinics 4 moved from city 3 miscarried 5 no longer interested 2 illness 1 wanted to take DHA 3 primary caregivers said no At 5‐year follow‐up, data were available for 88 children in the omega‐3 group and 83 children in the placebo group, equating to 179/350 (51%) lost to follow‐up.
Selective reporting (reporting bias)	Low risk	Most expected outcomes were reported.
Other bias	Low risk	No apparent source of other bias.