Descriptive data by delivery year (5 years increments, after 1999)
| n (%) or median (IQR) | Delivery year | ||||
| 1993–1998* | 1999–2003 | 2004–2008 | 2009–2013 | 2014–2018 | |
| Pregnancies | 10 407 | 8345 | 9518 | 11 483 | 11 602 |
| First time pregnancies | 8651 (83.1) | 5368 (64.3) | 6104 (64.1) | 8039 (70) | 7846 (67.6) |
| Fertility rate | 2.9 (2.9–3.2) | 2.8 (2.5–2.9) | 2.7 (2.6–2.8) | 2.5 (2.4–2.5) | 2.0 (1.9–2.2) |
| Median age | 25.1 (20–31.5) | 24.9 (19.8–31.2) | 24.6 (19.8–30.6) | 24.9 (20.4–30.7) | 25.8 (21.2–31.3) |
| Missing | 47 (0.5) | 0 (0) | 2 (0) | 1 (0) | 6 (0.1) |
| Median antenatal visits | 4 (2–6) | 4 (3–5) | 4 (2–5) | 4 (2–5) | 6 (5–7) |
| 0–3 | 1206 (11.6) | 2967 (35.6) | 3732 (39.2) | 4181 (36.4) | 1369 (11.8) |
| 4–7 | 1825 (17.5) | 4883 (58.5) | 5379 (56.5) | 6710 (58.4) | 6728 (58) |
| 8+ | 217 (2.1) | 484 (5.8) | 364 (3.8) | 535 (4.7) | 2298 (19.8) |
| Missing | 7159 (68.8) | 11 (0.1) | 43 (0.5) | 57 (0.5) | 1207 (10.4) |
| Median years of education | 10 (10–11) | 11 (10–11) | 11 (10–11) | 11 (10–12) | 11 (11–12) |
| No school | 669 (6.4) | 1124 (13.5) | 622 (6.5) | 423 (3.7) | 350 (3) |
| Primary education (1–7 years) | 57 (0.5) | 119 (1.4) | 104 (1.1) | 93 (0.8) | 82 (0.7) |
| Secondary education (8–12 years) | 2158 (20.7) | 6488 (77.7) | 8045 (84.5) | 9997 (87.1) | 10 223 (88.1) |
| Tertiary education (>12 Years) | 156 (1.5) | 495 (5.9) | 421 (4.4) | 574 (5) | 672 (5.8) |
| Missing | 7367 (70.8) | 119 (1.4) | 326 (3.4) | 396 (3.4) | 275 (2.4) |
| Current student | 2660 (25.6) | 1958 (23.5) | 2475 (26) | 2618 (22.8) | 2064 (17.8) |
| Have/intend to return to school | 2047 (19.7) | 1461 (17.5) | 1965 (20.6) | 2208 (19.2) | 1791 (15.4) |
| Unintended pregnancy | 3959 (38) | 4011 (48.1) | 4453 (46.8) | 4961 (43.2) | 5177 (44.6) |
| Modern contraceptive use prior to pregnancy | 2008 (19.3) | 3142 (37.7) | 3393 (35.6) | 3414 (29.7) | 2720 (23.4) |
| None | 7419 (71.3) | 4507 (54) | 4196 (44.1) | 5258 (45.8) | 7220 (62.2) |
| Injectables | 1282 (12.3) | 2304 (27.6) | 2684 (28.2) | 2415 (21) | 1631 (14.1) |
| Pills | 712 (6.8) | 796 (9.5) | 607 (6.4) | 640 (5.6) | 579 (5) |
| Condoms | 6 (0.1) | 13 (0.2) | 90 (0.9) | 328 (2.9) | 487 (4.2) |
| Other | 41 (0.4) | 69 (0.8) | 43 (0.5) | 38 (0.3) | 47 (0.4) |
| Missing | 947 (9.1) | 656 (7.9) | 1898 (19.9) | 2804 (24.4) | 1638 (14.1) |
| Using/intending to use modern postpartum contraception | 3817 (36.7) | 3286 (39.4) | 3934 (41.3) | 5987 (52.1) | 7600 (65.5) |
| None | 5339 (51.3) | 4304 (51.6) | 3564 (37.4) | 2532 (22) | 2180 (18.8) |
| Injectables | 2863 (27.5) | 2889 (34.6) | 3445 (36.2) | 5117 (44.6) | 6520 (56.2) |
| Pills | 618 (5.9) | 324 (3.9) | 338 (3.6) | 401 (3.5) | 627 (5.4) |
| Condoms | 10 (0.1) | 17 (0.2) | 82 (0.9) | 376 (3.3) | 384 (3.3) |
| Emergency contraception | 267 (2.6) | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| Sterilisation | 47 (0.5) | 46 (0.6) | 42 (0.4) | 33 (0.3) | 26 (0.2) |
| Other | 43 (0.4) | 28 (0.3) | 43 (0.5) | 61 (0.5) | 86 (0.7) |
| Missing | 1220 (11.7) | 737 (8.8) | 2004 (21.1) | 2963 (25.8) | 1779 (15.3) |
| Delivery location | |||||
| Hospital | 6596 (63.4) | 5702 (68.3) | 7226 (75.9) | 9527 (83) | 10 132 (87.3) |
| Clinic | 632 (6.1) | 486 (5.8) | 605 (6.4) | 493 (4.3) | 377 (3.2) |
| Health centre | 198 (1.9) | 503 (6) | 561 (5.9) | 653 (5.7) | 612 (5.3) |
| Home | 2799 (26.9) | 1492 (17.9) | 910 (9.6) | 548 (4.8) | 298 (2.6) |
| Other | 105 (1) | 111 (1.3) | 147 (1.5) | 145 (1.3) | 98 (0.8) |
| Missing | 77 (0.7) | 51 (0.6) | 69 (0.7) | 117 (1) | 85 (0.7) |
| Birth attendant | |||||
| Doctor | 813 (7.8) | 838 (10) | 923 (9.7) | 1231 (10.7) | 1176 (10.1) |
| Nurse | 5406 (51.9) | 5802 (69.5) | 7331 (77) | 9143 (79.6) | 9920 (85.5) |
| Family member | 1966 (18.9) | 1018 (12.2) | 682 (7.2) | 397 (3.5) | 190 (1.6) |
| Community member | 330 (3.2) | 212 (2.5) | 86 (0.9) | 78 (0.7) | 43 (0.4) |
| Nobody | 332 (3.2) | 271 (3.2) | 172 (1.8) | 106 (0.9) | 70 (0.6) |
| Other | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 3 (0) |
| Missing | 1538 (14.8) | 185 (2.2) | 295 (3.1) | 502 (4.4) | 189 (1.6) |
| Nationality | |||||
| South African | 6421 (61.7) | 5431 (65.1) | 6367 (66.9) | 7892 (68.7) | 8337 (71.9) |
| Mozambican | 3962 (38.1) | 2913 (34.9) | 3139 (33) | 3557 (31) | 3189 (27.5) |
| Other | 1 (0) | 0 (0) | 8 (0.1) | 32 (0.3) | 64 (0.6) |
| Missing | 23 (0.2) | 1 (0) | 4 (0) | 2 (0) | 12 (0.1) |
| Residency status | |||||
| Permanent resident | 8081 (77.6) | 7436 (89.1) | 7879 (82.8) | 9088 (79.1) | 9297 (80.1) |
| Temporary migrant | 538 (5.2) | 591 (7.1) | 834 (8.8) | 1461 (12.7) | 1635 (14.1) |
| Other | 43 (0.4) | 256 (3.1) | 574 (6) | 660 (5.7) | 522 (4.5) |
| Missing | 1745 (16.8) | 62 (0.7) | 231 (2.4) | 274 (2.4) | 148 (1.3) |
*Table 1 presents aggregate data across 5-year increments across the study period (the first column includes 6 instead of 5 years). This allowed for fewer instances of data aggregation into other categories when sparse data existed. Rows with fewer than five individuals in any group of years have been collapsed into the ‘other’ group in each category to protect participant privacy.