Table 1.
The Characteristics of Demographics and Obstetrics
| BTCP n = 76,466 |
OTCP n = 77,481 |
UTCP n = 116,931 |
F/χ2 | P value | |
|---|---|---|---|---|---|
| Maternal age (year)a | 27.2 ± 4.6 | 27.7 ± 4.7d1 | 28.7 ± 4.6 d2,d3 | 2708.69 | < 0.01 |
| < 20 yearsb | 1453(1.9) | 1294(1.7) | 1277(1.1) | 5832.92 | < 0.01 |
| 20–24 yearsb | 19,958(26.1) | 16,664(21.5) | 17,486(15.0) | ||
| 25–29 yearsb | 36,188(47.3) | 37,128(47.9) | 55,035(47.1) | ||
| 30–34 yearsb | 14,059(18.4) | 16,056(20.7) | 29,702(25.4) | ||
| ≥ 35 yearsb | 4800(6.3) | 6323(8.2) | 13,405(11.5) | ||
| Unknown | 8(0.0) | 16(0.0) | 26(0.0) | ||
| Delivery modeb | 90.81 | < 0.01 | |||
| Vaginal | 35,616(46.6) | 37,968(49.0)d1 | 57,112(48.8) d2,f3 | ||
| Cesarean | 40,833(53.4) | 39,510(51.0) | 59,814(51.2) | ||
| Unknown | 17(0.0) | 3(0.0) | 5(0.0) | ||
| Gestational age (weeks) a | 38.9 ± 1.9 | 38.9 ± 1.7 f1 | 38.7 ± 1.7 d2,d3 | 117.36 | < 0.01 |
| Parityb | 4824.41 | < 0.01 | |||
| Nulliparous | 45,346(59.3) | 40,944(52.8)d1 | 50,793(43.4) d2,d3 | ||
| Multiparous | 31,120(40.7) | 36,537(47.2) | 66,138(56.6) | ||
| Educationb | 27.57 | < 0.01 | |||
| College and above | 21,564(28.2) | 23,096(29.8)d1 | 43,140(36.9) d2,d3 | ||
| Middle school | 52,462(68.6) | 51,683(66.7) | 69,754(59.7) | ||
| Primary school and below | 1963(2.6) | 1767(2.3) | 2041(1.7) | ||
| Unknown | 477(0.6) | 935(1.2) | 1996(1.7) | ||
| Marital statusb | 3.97 | < 0.05 | |||
| Married | 76,013(99.4) | 77,137(99.6)d1 | 116,430(99.6) d2,f3 | ||
| Single | 438(0.6) | 326(0.4) | 473(0.4) | ||
| Unknown | 15(0.0) | 18(0.0) | 28(0.0) | ||
| Delivery hospitalb | 401.63 | < 0.01 | |||
| Urban | 33,537(43.9) | 35,554(45.9)d1 | 56,678(48.5) d2,d3 | ||
| Rural | 42,928(56.1) | 41,924(54.1) | 60,249(51.5) | ||
| Unknown | 1(0.0) | 3(0.0) | 4(0.0) | ||
| Baby sexb | 13.22 | < 0.01 | |||
| Female | 36,686(48.0) | 37,790(48.8)d1 | 57,133(48.9) d2f3 | ||
| Male | 39,780(52.0) | 39,691(51.2) | 59,798(51.1) | ||
| SRBc, a | 1.084 | 1.050d1 | 1.047 d2,f3 | 15.97 | < 0.01 |
| Birth weight (kg) a | 3.34 ± 0.52 | 3.33 ± 0.52 d1 | 3.34 ± 0.51 f2,d3 | 10.29 | < 0.01 |
| Neonatal deathc | 0.912 | 1.110 | 1.130 | ||
| Male neonatal deathb | 283(44.0) | 253(48.5) d1 | 340(49.7) d2,d3 | 15.29 | < 0.01 |
| Female neonatal deathb | 310(48.2) | 228(43.7) | 301(43.9) | 30.83 | < 0.01 |
| Unknownb | 50(7.8) | 41(7.8) | 44(6.4) | ||
| Deliveries per daye | 141(121, 163) | 116(90, 162) d1 | 154(130, 181) d2,d3 | 47.98 | < 0.01 |
BTCP: Both the husband and wife of one couple were the only child of their parents, the couple were allowed to have Two Children in Policy (January 1, 2013 - May 29, 2014); OTCP: only the husband or wife of one couple was the only child of their parents, the couple were allowed to have Two Children in Policy (May 30, 2014 - December 31, 2015); UTCP: the Universal Two-Child Policy, every couple were allowed to have two children (January 1, 2016 - December 31, 2017). SRB: Sex Ratio at Birth. A analysis of variance test of Post Hoc Multiple Comparisons was used for normally continuous variables, and chi-square test for the categorical variables;
aThe normal distribution continuous data were presented as mean ± standard deviation, the data were compared using independent t test (χ2);
bThe categorical data were presented as numbers (frequencies, %), Chi-square test was used for categorical data (F);
cn (male) / n (female);
eThe non-normal distribution continuous data were presented as median (interquartile range), the data were compared using analysis of variance (F);
d1Statistically significant when BTCP compared to OTCP (P < 0.05);
d2Statistically significant when BTCP compared to UTCP (P < 0.05);
d3Statistically significant when OTCP compared to UTCP (P < 0.05);
f1Not statistically significant when BTCP compared to OTCP (P>0.05);
f2Not statistically significant when BTCP compared to UTCP (P>0.05);
f3Not statistically significant when OTCP compared to UTCP (P>0.05)