Lack of catch-up in weight gain may intermediate between pregnancies with hyperemesis gravidarum and reduced fetal growth: the Japan Environment and Children’s Study

Table 2 Nausea and vomiting of pregnancy, gestational weight gain, and birth outcomes by weight change in 1^st trimester

	Weight change from pre-pregnancy to 1^st trimester (7 to 14 weeks)
	> + 3%		> 0 to + 3%		> -3 to 0%		> -5 to -3%		≤ -5%
	n	%	n	%	n	%	n	%	n	%	p-value +
Severity of NVP symptoms
No nausea	5746	37%	5648	36%	3533	23%	427	3%	205	1%	< 0.001
Only nausea	11,364	29%	13,668	35%	10,955	28%	2083	5%	1196	3%
Vomiting, but able to eat	6810	26%	8394	32%	8023	30%	1964	7%	1315	5%
Vomiting and unable to eat	1055	11%	1815	18%	3090	31%	1544	15%	2480	25%
	mean	SD	mean	SD	mean	SD	mean	SD	mean	SD	p-value +
Gestational weight gain
Gestational weight gain, kg	12.8	3.8	10.4	3.3	9.2	3.4	7.9	3.7	6.6	4.3	< 0.001
Weight gain up to 7–14 weeks, kg	2.9	1.4	0.8	0.5	-0.6	0.5	-2.1	0.5	-4.0	1.3	< 0.001
―timing, weeks	11.3	1.6	11.0	1.6	10.9	1.6	11.0	1.6	11.2	1.5	< 0.001
Weight gain up to 20–28 weeks, kg	7.7	2.8	5.4	2.2	4.0	2.3	2.6	2.4	1.1	3.1	< 0.001
―timing, weeks	24.6	2.2	24.5	2.2	24.6	2.2	24.6	2.2	24.6	2.2	0.727
Weight gain from 1^st to 2^nd trimester	4.8	2.3	4.6	2.1	4.6	2.2	4.7	2.3	5.1	2.6	0.026
―difference in measurements, weeks	13.3	2.7	13.6	2.7	13.7	2.7	13.5	2.7	13.4	2.7	< 0.001
Birth outcomes
Gestational age at birth, weeks	39.3	1.7	39.3	1.6	39.3	1.6	39.3	1.6	39.2	1.6	0.084
Birth weight, grams	3038	436	3032	432	3024	427	3013	413	2999	417	< 0.001
Birth weight z-score, SD	0.09	1.0	0.07	1.0	0.05	1.0	0.03	1.0	0.01	1.0	< 0.001
Placental weight, grams	561	107	558	108	558	106	554	105	553	105	< 0.001

The following missing values were imputed: gestational weight gain (n = 1,801; 2.0% of the study sample), weight gain at 7–14 weeks (n = 10,840; 11.9%), measurement timing at 7–14 weeks (n = 9,752; 10.7%), weight gain at 20–28 weeks (n = 9,189; 10.1%), measurement timing at 20–28 weeks (n = 9,048; 9.9%), and placental weight (n = 3,562; 3.9%)
+ : test for linear trend
Bold p-values: statistically significant
NVP Nausea and vomiting of pregnancy, SD Standard deviation

ISSN: 1471-2393