Table 1.
Treatment, Parental, and Infant Characteristics for term, live-born, autologous, fresh and frozen/thawed embryo transfer infants born in the U.S. between 2007 and 2014, National ART Surveillance System (NASS).
| All Fresh or Frozen/Thawed Embryo Transfers | Fresh Embryo Transfers | Frozen/Thawed Embryo Transfers | |
|---|---|---|---|
|
| |||
| (N=180,184) | (N=124,286) | (N=55,898) | |
|
|
|||
| Treatment Characteristics | |||
| Blastocyst Transfer | 67,257 (37.33) | 67,257 (54.11) | NAa |
| Single Embryo Transfer | 49,496 (27.47) | 26,695 (21.48) | 22,801 (40.79) |
| Number of Embryos Transferred (Mean (SD)) | 1.94 (0.75) | 2.04 (0.74) | 1.72 (0.71) |
| Number of Oocytes Retrieved | 13.54 (7.54) | 13.50 (7.51) | NAa |
| ICSI Used | 94,605 (52.50) | 92,372 (74.32) | NAa |
| Preimplantation Genetics Testing/Screening Performed | 5,886 (3.27) | 5886 (4.75) | NAa |
| Assisted Hatching Used | 68,587 (38.06) | 40,696 (32.74) | 27,891 (49.90) |
| Maternal Demographics | |||
| Maternal Age (years) | 33.86 (4.17) | 33.72 (4.18) | 34.18 (4.11) |
| Maternal Weight | |||
| Normal or Underweight (BMI <= 25 kg/m2) | 87,869 (62.54) | 60,034 (61.62) | 27,835 (64.60) |
| Overweight (BMI > 25 and < 30 kg/m2) | 31,664 (22.53) | 22,239 (22.83) | 9,425 (21.87) |
| Obese (BMI > 30 kg/m2) | 20,987 (14.94) | 15,158 (15.56) | 5,829 (13.53) |
| Missing | 39,664 | ||
| Year of Cycle Initiation | |||
| 2007 | 18,204 (10.10) | 14,555 (11.71) | 3,649 (6.53) |
| 2008 | 19,708 (10.94) | 15,557 (12.52) | 4,151 (7.43) |
| 2009 | 20,100 (11.16) | 15,867 (12.77) | 4,233 (7.57) |
| 2010 | 20,934 (11.62) | 15,831 (12.74) | 5,103 (9.13) |
| 2011 | 21,877 (12.14) | 15,754 (12.68) | 6,123 (10.95) |
| 2012 | 24,167 (13.41) | 16,214 (13.05) | 7,953 (14.23) |
| 2013 | 26,123 (14.50) | 15,570 (12.53) | 10,553 (18.88) |
| 2014 | 29,071 (16.13) | 14,938 (12.02) | 14,133 (25.28) |
| Smoked >100 cigarettes in lifetime | 8,276 (4.59) | 5990 (4.82) | 2,286 (4.09) |
| Missing | 27,438 | ||
| Smoked during 3 months prior to cycled | 3,493 (2.31) | 2,524 (2.43) | 969 (2.05) |
| Missing | 173,651 | ||
| Infertility Diagnosis (nonexclusive) | |||
| Male Factor | 72,637 (40.31) | 50,699 (40.79) | 21,938 (39.25) |
| Diminished Ovarian Reserve | 26,124 (14.50) | 18,949 (15.25) | 7,175 (12.85) |
| Uterine Factor | 6,889 (3.82) | 4,457 (3.59) | 2,432 (4.35) |
| Endometriosis | 19,573 (10.86) | 13,761 (11.07) | 5,812 (10.40) |
| Ovulatory Disorder or Polycystic Ovaries | 32,446 (18.01) | 20,753 (16.70) | 11,693 (20.92) |
| Tubal Factor | 26,106 (14.49) | 18,280 (14.71) | 7,826 (14.00) |
| Hydrosalpinx c | 2,295 (1.27) | 1,584 (1.27) | 711 (1.27) |
| Tubal Ligation | 3,284 (1.82) | 2,479 (1.99) | 805 (1.44) |
| Other Tubal Cause c | 20,901 (11.60) | 14,462 (11.64) | 6,439 (11.52) |
| Other Cause | 23,273 (12.92) | 14,188 (11.42) | 9,085 (16.25) |
| Unexplained | 27,534 (15.28) | 19,757 (15.90) | 7,777 (13.91) |
| Maternal Pregnancy History | |||
| Number of Previous ART Cycles | |||
| No previous cycles | 82,836 (45.97) | 79,491 (63.96) | 3,345 (5.98) |
| 1–2 cycles | 72,699 (40.35) | 33,373 (26.85) | 39,326 (70.35) |
| 3 or more cycles | 24,649 (13.67) | 11,422 (9.19) | 13,227 (23.66) |
| One or More Previous Premature Birth(s) | 7,493 (4.17) | 3,331 (2.69) | 4,163 (7.46) |
| One or More Previous Miscarriage(s) | 51,972 (28.82) | 33,259 (26.76) | 18,713 (33.48) |
| Parity | |||
| One to two previous births | 56,286 (31.24) | 32,195 (25.90) | 24,091 (43.10) |
| No previous births | 120,071 (66.64) | 89,531 (72.04) | 30,540 (54.64) |
| 3 or more previous births | 3,827 (2.13) | 2,560 (2.06) | 1,267 (2.27) |
| Infant Variables | |||
| Birthweight (grams) | 3399.87 (472.37) | ||
| Low Birthweight (<2500 grams)) | 4,741 (2.63) | 3,855 (3.10) | 886 (1.59) |
| Normal Birthweight (2500–4000 grams)) | 157,721 (87.53) | 110,491 (88.90) | 47,230 (84.49) |
| Macrosomic (>4000 grams) | 17,722 (9.84) | 9,940 (8.00) | 7,782 (13.92) |
| Gestational Age (weeks) | 39.30 (1.08) | 39.35 (1.08) | 39.20 (1.06) |
| Female Sex | 89,007 (49.40) | 61,672 (49.62) | 27,335 (48.90) |
| Maternal Ethnicityb | |||
| Non-Hispanic White | 86,425 (74.43) | 60,329 (75.33) | 26,096 (72.42) |
| Non-Hispanic Black | 5,807 (5.00) | 3,937 (4.92) | 1,870 (5.19) |
| Asian or Pacific Islander | 14,631 (12.60) | 9,262 (11.57) | 5,369 (14.90) |
| Hispanic | 9,024 (7.77) | 6,389 (7.98) | 2,635 (7.31) |
| Other | 232 (0.20) | 169 (0.21) | 63 (0.17) |
| Missing | 64,065 | ||
| Paternal Ethnicityb | |||
| Non-Hispanic White | 81,703 (76.33) | 56,935 (77.11) | 24,768 (74.60) |
| Non-Hispanic Black | 5,732 (5.36) | 3,934 (5.33) | 1,798 (5.42) |
| Asian or Pacific Islander | 11,682 (10.91) | 7,333 (9.93) | 4,349 (13.10) |
| Hispanic | 7,724 (7.22) | 5,496 (7.44) | 2,228 (6.71) |
| Other | 193 (0.18) | 135 (0.18) | 58 (0.17) |
| Missing | 73,150 | ||
All data are presented as number (percent) of participants except where otherwise specified; SD = Standard Deviation
a
Data were not available for some treatment variables for infants conceived using frozen/thawed embryo transfers.
b
Missing maternal and paternal race data were imputed
c
No significant differences between the frozen/thawed embryo and fresh embryo groups for these two variables. All other variables were significantly different between the groups.
d
Question was only asked of those who reported having smoked >100 cigarettes in their lifetime