Table 2

Pregnancy and offspring characteristics stratified by maternal height in quintiles1
Pregnancy characteristics Maternal height by quintiles(cm)
<163 163-165 166-168 169-172 >173
n=1192 n=930 n=1032 n=1053 n=803 P for trend
Mean age at delivery, years (SE) 30.3(0.2) 30.5(0.2) 30.3(0.2) 30.2(0.2) 30.6(0.17) 0.83
Mean time from baseline to delivery, years (SE) 4.2(0,1) 4.3(0.1) 4.3(0.1) 4.4(0.1) 4.4(0.1) 0.01
Mean pregnancy length, days, LMP-based (SE)2 279.3(0.5) 280.2(0.5) 281.5(0.6) 281.5(0.5) 282.0(0.6) <0.0001
Mean pregnancy length, days, US-based (SE)3 276.7(0.5) 277.9(0.5) 279.2(0.6) 280.1(0.5) 280.9(0.5) <0.0001
Primiparous mother (%)4 327(27) 241(26) 300(29) 309(29) 236(29) 0.06
Mean birth weight, grams (SE)5 3490(20) 3618(21) 3655(22) 3692(20) 3803(25) <0.0001
Male fetal sex (%) 626(52.5) 495(53.2) 531(51.5) 574(54.5) 402(50.1) 0.61
Onset of labour (%)
 Spontaneous 873(73.2) 740(79.6) 835(80.9) 868(82.4) 624(77.7) 0.002
 Medically induced 144(12.1) 111(11.9) 137(13.3) 127(12.1) 114(14.2) 0.26
 CS before labour6 175(14.7) 79(8,5) 60(5.8) 58(5.5) 65(8.1) <0.0001
CS, total number (%)7 302(25) 162(17) 133(13) 100(9.5) 100(12.5) <0.0001
 Acute CS8 154(17.9) 64(6.9) 52(5.0) 48(4.6) 49(6.1) <0.0001
 Elective CS9 148(12.4) 98(10.5) 81(7.9) 52(4.9) 51(6.4) <0.0001
SGA < 2.5 percentile (%)10 41(3.4) 12(1.3) 18(1.8) 13(1.2) 9(1.1) 0.001
Preeclampsia (%) 50(4.2) 27(2.9) 40(3.9) 31(2.9) 30(3.7) 0.52
Stillbirth (%)11 4(0.3) 3(0.3) 4(0.4) 4(0.4) 2(0.3) 0.89

CS = Caesarian section, SE= Standard Error, LMP= last menstrual period, US= ultrasound early second trimester, SGA= small for gestational age.

1Data from 5010 singleton pregnancies of 3497 mothers, registered in the Medical Birth Registry of Norway 1995–2005. 2Missing data on LMP for 164 pregnancies. 3Missing data on US for 972 pregnancies. 4Primiparous=woman with no previous birth. 5Missing data on birth weight for 1 woman. 6Elective and acute caesarian section before labour. 7Elective and acute caesarian sections before and after onset of labour. 8Planned and performed less than 8 hours after decision was made. 9Planned and performed more than 8 hours after decision was made. 10Missing data on SGA for 5 pregnancies. 11Missing data on stillbirth for 1 woman.

Myklestad et al.

Myklestad et al. BMC Pregnancy and Childbirth 2013 13:33   doi:10.1186/1471-2393-13-33

Open Data