Table 2.

Pregnancy weight gain for gestational age among normal weight women with twin pregnancies at Magee-Womens Hospital, Pittsburgh PA, 1998–2013.

Normal weight women (Pre-pregnancy BMI 18.5–24.9)
Gestational age (week)	Weight observations (N)	Weight gain (kg)
		p3	p10	p50	p90	p97	Log mean	Log SD
5	20	−3.8	−2.9	−0.4	3.4	5.9	1.97	0.336
6	34	−3.5	−2.7	−0.1	3.8	6.3	2.015	0.329
7	77	−3.3	−2.4	0.3	4.3	6.8	2.06	0.321
8	139	−3	−2.1	0.6	4.7	7.2	2.105	0.315
9	140	−2.8	−1.8	1	5.1	7.7	2.15	0.308
10	140	−2.5	−1.5	1.4	5.6	8.2	2.195	0.301
11	128	−2.2	−1.2	1.8	6.1	8.8	2.24	0.295
12	135	−1.9	−0.8	2.2	6.6	9.3	2.285	0.289
13	151	−1.5	−0.4	2.7	7.2	9.9	2.33	0.283
14	137	−1.2	0	3.2	7.8	10.5	2.376	0.277
15	142	−0.8	0.4	3.7	8.4	11.2	2.423	0.271
16	141	−0.4	0.8	4.2	9	11.9	2.47	0.266
17	139	0	1.3	4.8	9.7	12.7	2.518	0.261
18	151	0.5	1.8	5.4	10.5	13.5	2.567	0.256
19	145	0.9	2.3	6.1	11.3	14.4	2.617	0.252
20	165	1.5	2.9	6.8	12.2	15.4	2.668	0.248
21	148	2	3.5	7.6	13.2	16.4	2.72	0.244
22	165	2.6	4.2	8.4	14.2	17.6	2.773	0.241
23	173	3.2	4.8	9.3	15.3	18.8	2.825	0.237
24	190	3.8	5.5	10.2	16.4	20	2.876	0.235
25	205	4.4	6.2	11.1	17.5	21.3	2.925	0.233
26	214	5.1	6.9	11.9	18.6	22.5	2.971	0.231
27	209	5.6	7.6	12.8	19.7	23.7	3.013	0.229
28	275	6.2	8.2	13.5	20.7	24.8	3.05	0.228
29	260	6.6	8.7	14.2	21.6	25.8	3.081	0.227
30	330	7	9.1	14.8	22.4	26.7	3.108	0.227
31	285	7.4	9.5	15.3	23.1	27.6	3.133	0.228
32	379	7.7	10	15.9	23.9	28.5	3.157	0.228
33	334	8.1	10.4	16.5	24.8	29.5	3.183	0.229
34	434	8.5	10.9	17.2	25.8	30.7	3.212	0.231
35	403	9	11.4	18	26.9	32.1	3.244	0.233
36	295	9.4	12	18.9	28.2	33.6	3.277	0.235
37	190	9.9	12.6	19.8	29.6	35.3	3.311	0.238
38	94	10.4	13.3	20.8	31	37	3.346	0.241
39	20	11	13.9	21.8	32.6	38.9	3.38	0.244