Figure 1 Meanandrespective95%confidenceintervalsforplacentalweightaccording to fetal gender for each GA.

Figure 2 Mean and respective 95% confidence intervals, for the birth weight according to the fetal gender for each GA.

Legend: CI, confidence interval; g, grams; GA, gestational age; F, female; M, male.

Figure 3Placental weight percentile curves by gestational age, Nogueira R, et al., Portugal, Porto, Embryofetal Pathology Laboratory.

Figure 4Birthweight percentile curves by gestational age, Nogueira R, et al. Portugal, Porto, Embryofetal PathologyLaboratory.

Figure 5Birth/placental weight ratio percentile curves by gestational age, Nogueira R, et al., Portugal, Porto, Embryofetal Pathology Laboratory.

Figure 6Placental/birth weight ratio (PW-R) percentile curves by gestational age, Nogueira R, et al., Portugal, Porto, Embryofetal Pathology Laboratory.

Figure 7Relation between placental measures.

Legend: g, grams; Diameter >, largest placental diameter; Diameter <, smallest placental diameter.

	Valid (N)	Mean	SD	Median	Min	Max
MA (y)	1947	31.8	6.1	32.1	15.1	48.2
GA (w)	1951	27	9	26	12	41
PW (g)	1951	233.25	159.25	195.00	6.00	995
PD (cm)	1949	13.5	5.0	13.0	1.7	32.0
PT (cm)	1947	2.11	.70	2.00	.30	5.50
FW (g)	1951	1248.70	1153.93	766.00	5.40	4880

Table 1. Summary statistics for some important fetal, placental and maternal quantitative variables

Legend: SD, standard deviation; Min, minimum; Max, maximum; MA, maternal age; GA, gestational age; PW, placental weight; PD, placental diameter; PT, placental thickness; FW, fetal weight; y, years; w, weeks; g, grams; cm, centimeters.

		N	Percent
Mother Parity	1	820	45.2%
	2	595	32.8%
	3+	400	22.0%
	Total	1815	100.0%
Fetal Gender	F	818	47.7%
	M	884	51.5%
	A	13	.8%
	Total	1715	100.0%
Placental Shape	Normal	1731	88.7%
	Bilobed	113	5.8%
	Circumvallate	104	5.3%
	Membranacea	3	.2%
	Total	1951	100,0%

Table 2. Summary statistics for some important fetal, placental and maternal qualitative variables

Legend: F, female; M, male; A, ambiguous.

Percentile							Placental weight (g)
GA	3rd	10th	50th	90th	97th	Number	Mean	SD
12	10	13	33	67.3	96	53	36.72	23.93
13	10	21	38	60	74	61	40.79	17.29
14	20.6	30	49.5	75	88	68	51.22	17.96
15	16	36	58	90	108	72	60.03	23.53
16	23.8	43	71	100	108	72	71.36	25.04
17	44	57	89	126	160	69	95.39	38.05
18	51.3	60	95	132	149	73	95	32.49
19	41	68	114	160	169	72	113.39	35.67
20	57	83	120	166	190	69	126.69	45.79
21	68	103	143.3	184	200	71	141.89	35.44
22	74	104	141	191	220	71	145.28	39.37
23	88	123	174	223	243	72	172.19	44.78
24	97	107	153.5	241	260	68	170.6	55.81
25	74	82	184	270	330	48	181.94	69.42
26	88	100	190	288	319	43	190.67	71.35
27	76	131	238.65	289	291	35	220.3	73.23
28	96	123	202	307	351	61	203.38	67.66
29	134	154	240	365	434	43	254.84	89.83
30	99.6	151	247	345	423	47	249.1	77
31	114	145	293.5	405	462	56	280.46	90.97
32	182	203	307	471	512	67	314.61	89.16
33	190	222	334.5	442	515	72	336.67	88.37
34	195	253	344	448	496	72	341.94	84.01
35	200	237	356	546	654	75	374.79	123.68
36	237	267	350	490	515	77	361.16	80.6
37	242	275.3	364.5	507	593	72	380.02	91.21
38	273	296	405	590	755	72	433.61	136.89
39	259	312	444	610	678	71	450.38	128.09
40	335	378	459	580	632	77	475.44	90.66
41	327	353	470	615	690	72	478.18	105.99

Table 3. Percentiles, number of observations, the mean and standard deviation for placental weight in the function of GA

Legend: GA, gestational age; g, grams; SD, standard deviation. Nogueira R, et al.,Portugal, Porto, Embryofetal Pathology Laboratory.

Percentile							Birthweight (g)
GA	3rd	10th	50th	90th	97th	Number	Mean	SD
12	5.7	9.3	16	29	111	53	23.83	38.99
13	6.7	16	27	41	46	61	28.22	20.96
14	16	24	46	70	77	68	44.72	17.3
15	15	24	70.5	100	120	72	67.86	32.27
16	25	44	99.35	164	185	72	99.8	44.33
17	75	89	166	226	266	69	165.63	51.58
18	66.5	122	209	261	309	73	201.52	56.84
19	56	127	261	333	402	72	253.83	86.96
20	141	242	325	430	455	69	330.38	81.85
21	190	296	409	497	535	71	400.56	86.21
22	241	353	495	589	648	71	486.48	141.64
23	325	411	565.5	700	772	72	560.09	109.35
24	343	444	642.5	786	854	68	637.79	143.32
25	179	280	731	870	1175	48	678.61	332.26
26	364	460	640	925	1670	43	710.84	293.23
27	488	620	958	1150	1200	35	911.78	192.51
28	300	549	960	1240	1400	61	928.62	270.84
29	497	638	1075	1720	2160	43	1203.65	488.27
30	660	845	1275	1730	1860	47	1267.34	349.7
31	796	920	1469.5	1930	2180	56	1479.11	358.7
32	937	1219	1750	2250	2500	67	1759.27	487.78
33	1177	1500	1960	2360	2490	72	1931.08	391.98
34	1331	1515	2095	2690	2860	72	2136.57	443.36
35	1530	1720	2270	2850	3640	75	2337.69	561.11
36	1640	1860	2440	3175	3390	77	2454.43	457.96
37	2000	2140	2450	2995	3690	72	2570.04	513.11
38	2090	2200	2737.5	3580	4120	72	2846.26	587.45
39	1930	2230	2780	3660	3840	71	2882.54	590.53
40	2400	2580	3230	3860	3940	77	3253.27	477.65
41	2500	2600	3312.5	3900	4210	72	3308.19	507.44

Table 4. Percentiles, number of observations, the mean and standard deviation for birthweight in the function of GA

Legend: GA, gestational age; g, grams; SD, standard deviation. Nogueira R, et al., Portugal, Porto, Embryofetal Pathology Laboratory.

Percentile							BPW-R
GA	3rd	10th	50th	90th	97th	Number	Mean	SD
12	.21	.28	.51	1.22	1.97	53	.68	.47
13	.32	.41	.63	1.06	2.5	61	.76	.46
14	.35	.51	.94	1.32	1.38	68	.92	.32
15	.34	.53	1.1	1.92	2.48	72	1.19	.55
16	.54	.68	1.41	2.11	2.32	72	1.43	.52
17	.83	1	1.78	2.71	3.16	69	1.86	.68
18	1	1.37	2.18	3.04	3.66	73	2.25	.76
19	.93	1.47	2.28	3.06	3.77	72	2.28	.69
20	1.41	1.92	2.59	4	4.39	69	2.78	.81
21	1.6	2.13	2.84	3.99	4.5	71	2.95	.82
22	1.97	2.34	3.41	4.5	5.57	71	3.45	.88
23	2.12	2.38	3.36	4.69	5.21	72	3.43	.91
24	2.35	2.67	3.82	5.15	6.1	68	3.94	1
25	1.82	2.23	3.56	5.22	7	48	3.83	1.57
26	2.16	2.55	3.9	5.14	6.44	43	3.93	1.19
27	2.66	3.39	4.09	6.42	7.08	35	4.45	1.2
28	2.45	3.09	4.82	6.45	7.7	61	4.77	1.35
29	2.91	3.19	4.63	6.27	7.74	43	4.85	1.49
30	3.52	3.73	5.42	6.74	7.68	47	5.28	1.16
31	3.58	4.17	5.42	6.99	8.07	56	5.54	1.17
32	3.78	4.12	5.67	7.53	7.95	67	5.74	1.28
33	3.82	4.33	5.96	7.37	8.63	72	5.96	1.26
34	4.59	4.91	6.45	7.98	8.91	72	6.49	1.78
35	4.73	5.04	6.45	8.1	8.53	75	6.48	1.18
36	4.58	5.3	6.93	8.89	9.77	77	6.96	1.31
37	4.96	5.46	6.76	8.89	9.69	72	6.95	1.27
38	4.64	5.29	6.93	8.56	9.51	72	6.86	1.38
39	3.96	4.96	6.53	8.5	8.88	71	6.65	1.34
40	4.82	5.68	6.92	8.57	8.98	77	6.97	1.07
41	5.35	5.95	7	8	9.16	72	7.07	.94

Table 5. Percentiles, number of observations, the mean and standard deviation for birth/placental weight ratio (BPW-R) in the function of GA

Legend: GA, gestational age; SD, standard deviation. Nogueira R, et al., Portugal, Porto, Embryofetal Pathology Laboratory.

Percentile							PW-R
GA	3rd	10th	50th	90th	97th	Number	Mean	SD
12	.51	.82	1.96	3.55	4.84	53	2.22	1.77
13	.40	.94	1.59	2.45	3.10	61	1.63	.67
14	.72	.76	1.07	1.96	2.83	68	1.27	.60
15	.40	.52	.91	1.89	2.90	72	1.08	.72
16	.43	.47	.71	1.47	1.86	72	.84	.47
17	.32	.37	.56	1.00	1.20	69	.62	.26
18	.27	.33	.46	.73	1.00	73	.50	.20
19	.27	.33	.44	.68	1.07	72	.50	.28
20	.23	.25	.39	.52	.71	69	.40	.15
21	.22	.25	.35	.47	.63	71	.37	.10
22	.18	.22	.29	.43	.51	71	.31	.08
23	.19	.21	.30	.42	.47	72	.31	.08
24	.16	.19	.26	.37	.43	68	.27	.07
25	.14	.19	.28	.45	.55	48	.29	.10
26	.16	.19	.26	.39	.46	43	.28	.09
27	.14	.16	.24	.30	.38	35	.24	.07
28	.13	.16	.21	.32	.41	61	.23	.07
29	.13	.16	.22	.31	.34	43	.22	.06
30	.13	.15	.18	.27	.28	47	.20	.05
31	.12	.14	.18	.24	.28	56	.19	.04
32	.13	.13	.18	.24	.26	67	.19	.07
33	.12	.14	.17	.23	.26	72	.18	.05
34	.11	.13	.15	.20	.22	72	.16	.03
35	.12	.12	.16	.20	.21	75	.16	.03
36	.10	.11	.14	.19	.22	77	.15	.03
37	.10	.11	.15	.18	.20	72	.15	.03
38	.11	.12	.14	.19	.22	72	.15	.03
39	.11	.12	.15	.20	.25	71	.16	.04
40	.11	.12	.14	.18	.21	77	.15	.02
41	.11	.13	.14	.17	.19	72	.14	.02

Table 6. Percentiles, number of observations, mean and standard deviation for placental weight ratio (PW-R) in function of GA

Legend: GA, gestational age; SD, standard deviation. Nogueira R, et al., Portugal, Porto, Embryofetal Pathology Laboratory.

Correlations

Placental Weight (g)			Placental Volume	Largest Placental Diameter	Smallest Placental Diameter	Placental Thickness
Placental Weight (g)	Pearson Correlation	1	,883**	,826**	,829**	,619**
	Sig. (2-tailed)		,000	,000	,000	,000
	N	1951	1944	1949	1948	1947
Placental Volume	Pearson Correlation	,883**	1	,883**	,877**	,621**
	Sig. (2-tailed)	,000		,000	,000	,000
	N	1944	1944	1944	1944	1944
Largest Placental Diameter	Pearson Correlation	,826**	,883**	1	,918**	,396**
	Sig. (2-tailed)	,000	,000		,000	,000
	N	1949	1944	1949	1948	1945
Smallest Placental Diameter	Pearson Correlation	,829**	,877**	,918**	1	,398**
	Sig. (2-tailed)	,000	,000	,000		,000
	N	1948	1944	1948	1948	1944
Placental Thickness	Pearson Correlation	,619**	,621**	,396**	,398**	1
	Sig. (2-tailed)	,000	,000	,000	,000
	N	1947	1944	1945	1944	1947

Table 7. Correlation between placental measures, placental weight and placental volume

**. Correlation is significant at the 0.01 level (2-tailed). Nogueira R, et al., Portugal, Porto, Embryofetal Pathology Laboratory