Impact on birth weight and child growth of Participatory Learning and Action women’s groups with and without transfers of food or cash during pregnancy: Findings of the low birth weight South Asia cluster-randomised controlled trial (LBWSAT) in Nepal

Background
Undernutrition during pregnancy leads to low birthweight, poor growth and inter-generational undernutrition. We did a non-blinded cluster-randomised controlled trial in the plains districts of Dhanusha and Mahottari, Nepal to assess the impact on birthweight and weight-for-age z-scores among children aged 0–16 months of community-based participatory learning and action (PLA) women’s groups, with and without food or cash transfers to pregnant women.
Methods
We randomly allocated 20 clusters per arm to four arms (average population/cluster = 6150). All consenting married women aged 10–49 years, who had not had tubal ligation and whose husbands had not had vasectomy, were monitored for missed menses. Between 29 Dec 2013 and 28 Feb 2015 we recruited 25,092 pregnant women to surveillance and interventions: PLA alone (n = 5626); PLA plus food (10 kg/month of fortified wheat-soya ‘Super Cereal’, n = 6884); PLA plus cash (NPR750≈US$7.5/month, n = 7272); control (existing government programmes, n = 5310). 539 PLA groups discussed and implemented strategies to improve low birthweight, nutrition in pregnancy and hand washing. Primary outcomes were birthweight within 72 hours of delivery and weight-for-age z-scores at endline (age 0–16 months). Only children born to permanent residents between 4 June 2014 and 20 June 2015 were eligible for intention to treat analyses (n = 10936), while in-migrating women and children born before interventions had been running for 16 weeks were excluded. Trial status: completed.
Results
In PLA plus food/cash arms, 94–97% of pregnant women attended groups and received a mean of four transfers over their pregnancies. In the PLA only arm, 49% of pregnant women attended groups. Due to unrest, the response rate for birthweight was low at 22% (n = 2087), but response rate for endline nutritional and dietary measures exceeded 83% (n = 9242). Compared to the control arm (n = 464), mean birthweight was significantly higher in the PLA plus food arm by 78·0 g (95% CI 13·9, 142·0; n = 626) and not significantly higher in PLA only and PLA plus cash arms by 28·9 g (95% CI -37·7, 95·4; n = 488) and 50·5 g (95% CI -15·0, 116·1; n = 509) respectively. Mean weight-for-age z-scores of children aged 0–16 months (average age 9 months) sampled cross-sectionally at endpoint, were not significantly different from those in the control arm (n = 2091). Differences in weight for-age z-score were as follows: PLA only -0·026 (95% CI -0·117, 0·065; n = 2095); PLA plus cash -0·045 (95% CI -0·133, 0·044; n = 2545); PLA plus food -0·033 (95% CI -0·121, 0·056; n = 2507). Amongst many secondary outcomes tested, compared with control, more institutional deliveries (OR: 1.46 95% CI 1.03, 2.06; n = 2651) and less colostrum discarding (OR:0.71 95% CI 0.54, 0.93; n = 2548) were found in the PLA plus food arm but not in PLA alone or in PLA plus cash arms.
Interpretation
Food supplements in pregnancy with PLA women’s groups increased birthweight more than PLA plus cash or PLA alone but differences were not sustained. Nutrition interventions throughout the thousand-day period are recommended.
Trial registration
ISRCTN75964374.

研究背景
妊娠期营养不良可导致低出生体重、生长发育不良以及代际营养不良。本研究在尼泊尔达努沙（Dhanusha）和马奥塔里（Mahottari）平原地区开展一项非盲整群随机对照试验，旨在评估基于社区的参与式学习与行动（Participatory Learning and Action，PLA）妇女小组联合/不联合向孕妇提供食物或现金补助，对0~16月龄儿童出生体重及年龄别体重z评分的影响。

研究方法
本研究按研究组随机分配20个整群至4个研究组（每个整群平均人口数为6150）。对所有签署知情同意、年龄10~49岁的已婚女性（未接受输卵管结扎且其丈夫未接受输精管结扎）进行月经逾期监测。2013年12月29日至2015年2月28日期间，本研究共招募25092名孕妇纳入监测与干预：仅PLA组（n=5626）；PLA联合食物补助组（每月给予10kg强化小麦大豆“超级谷物”，n=6884）；PLA联合现金补助组（每月750尼泊尔卢比，约合7.5美元，n=7272）；对照组（沿用现有政府项目，n=5310）。共组建539个PLA小组，讨论并实施改善低出生体重、妊娠期营养及手卫生的相关策略。本研究的主要结局指标为分娩后72小时内的出生体重，以及终点随访时（儿童年龄0~16月龄）的年龄别体重z评分。仅纳入2014年6月4日至2015年6月20日期间常住居民所生育的儿童进行意向治疗分析（n=10936），迁入的孕妇以及干预实施16周前出生的儿童均被排除。本试验已完成。

研究结果
在PLA联合食物/现金补助组中，94%~97%的孕妇参与了小组活动，且妊娠期间平均获得4次补助。仅PLA组中，49%的孕妇参与了小组活动。受动乱影响，出生体重数据的应答率较低，仅为22%（n=2087），但终点随访时营养与膳食指标的应答率超过83%（n=9242）。与对照组（n=464）相比，PLA联合食物补助组的平均出生体重显著升高78.0g（95%CI：13.9~142.0；n=626）；仅PLA组与PLA联合现金补助组的平均出生体重无显著升高，分别增加28.9g（95%CI：-37.7~95.4；n=488）与50.5g（95%CI：-15.0~116.1；n=509）。在终点横断面抽样的0~16月龄儿童（平均年龄9月龄）中，其平均年龄别体重z评分与对照组（n=2091）无显著差异。各研究组的年龄别体重z评分差异如下：仅PLA组为-0.026（95%CI：-0.117~0.065；n=2095）；PLA联合现金补助组为-0.045（95%CI：-0.133~0.044；n=2545）；PLA联合食物补助组为-0.033（95%CI：-0.121~0.056；n=2507）。在多项检测的次要结局指标中，与对照组相比，PLA联合食物补助组的住院分娩率更高（优势比OR=1.46，95%CI：1.03~2.06；n=2651），初乳丢弃率更低（OR=0.71，95%CI：0.54~0.93；n=2548），而仅PLA组与PLA联合现金补助组未出现此类差异。

研究解读
与仅PLA组或PLA联合现金补助组相比，妊娠期联合PLA妇女小组与食物补充剂可更显著提升儿童出生体重，但该差异未持续存在。本研究建议在生命最初1000天全程开展营养干预。

试验注册
ISRCTN75964374。