Table 1 Baseline characteristics of included pregnancies (N = 3027)
Variables | Â |
|---|---|
Maternal age | 30.8 ± 4.6 (range: 17–52) |
Nulliparity | 2034 (67.2) |
ART conceived pregnancies | 1981 (65.4) |
Monochorionic twins | 542 (17.9) |
Fetal sex | Â |
Male-male | 1053 (34.8) |
Female-female | 874 (28.9) |
Male-female | 1100 (36.3) |
Preexisting diabetes mellitus | 29 (1.0) |
Preexisting hypertension | 24 (0.8) |
Syphilis | 8 (0.3) |
Hepatitis B | 234 (7.7) |
Hypertensive disorders of pregnancy | 342 (11.3) |
Gestational diabetes mellitus | 615 (20.3) |
Idiopathic jaundice of pregnancy | 81 (2.7) |
Caesarean section | 2974 (98.3) |
Gestational age at delivery | 35.8 ± 1.8 |
Classification of twin birth weight | Â |
Singleton standards | Â |
Small for gestational age | 2002 (33.1) |
Appropriate for gestational age | 4036 (66.7) |
Large for gestational age | 16 (0.3) |
Twin standards | Â |
Small for gestational age | 443 (7.3) |
Appropriate for gestational age | 5322 (87.9) |
Large for gestational age | 289 (4.8) |