TABLE 2.

Assisted hatching and cycle outcomes, day-3 embryo transfers, fresh autologous ART cycles, United States, 2000–2010.

Patient groups and cycle outcomes^a	No. and percentage of cycle outcomes				Association between assisted hatching and cycle outcomes
	Used assisted hatching		Did not use assisted hatching
	n	%	n	%	OR (95% CI)	aOR (95% CI)^c
All patients (N = 536,852)
Implantation	136,631	15.8	141,166	22.1	0.66 (0.61, 0.71)	0.72 (0.67, 0.77)
Clinical pregnancy	106,399	36.2	106,257	43.8	0.73 (0.67, 0.79)	0.80 (0.74, 0.86)
Live birth	83,125	28.3	88,521	36.5	0.69 (0.64, 0.74)	0.75 (0.70, 0.81)
Miscarriage	20,017	18.9	14,228	13.5	1.49 (1.40, 1.60)	1.43 (1.34, 1.52)
Multiple gestation
1 embryo transferred	74	2.0	47	1.3	1.59 (1.17, 2.16)	1.77 (1.31, 2.38)
≥2 embryos transferred	31,887	31.1	35,281	34.4	0.86 (0.82, 0.89)	0.90 (0.87, 0.94)
Patients ≥38 y, or ≥2 prior ART cycles and no live birth (N = 227,372)
Implantation	59,452	11.3	28,892	13.5	0.81 (0.76, 0.86)	0.84 (0.79, 0.90)
Clinical pregnancy	47,375	29.5	21,816	32.7	0.86 (0.79, 0.93)	0.89 (0.82, 0.97)
Live birth	33,279	20.7	16,054	24.1	0.82 (0.77, 0.88)	0.86 (0.80, 0.92)
Miscarriage	12,459	26.4	4,924	22.7	1.22 (1.13, 1.32)	1.19 (1.12, 1.28)
Multiple gestation	11,425	24.1	5,680	26.0	0.90 (0.86, 0.95)	0.93 (0.89, 0.98)
Patients <38 y, and <2 prior ART cycles or live birth (N = 297,972)
Implantation	77,035	22.8	112,181	26.5	0.82 (0.76, 0.88)	0.86 (0.80, 0.92)
Clinical pregnancy	56,557	44.6	82,695	48.3	0.86 (0.80, 0.93)	0.91 (0.84, 0.98)
Live birth	47,747	37.7	70,956	41.4	0.85 (0.79, 0.92)	0.90 (0.83, 0.97)
Miscarriage	7,248	12.9	9,122	11.1	1.18 (1.13, 1.24)	1.16 (1.11, 1.22)
Multiple gestation
1 embryo transferred	43	2.2	32	1.1	2.05 (1.34, 3.14)	2.20 (1.45, 3.32)
≥2 embryos transferred	19,587	35.9	28,966	36.3	0.98 (0.94, 1.02)	1.01 (0.96, 1.05)
Poor-prognosis patients (N = 6,511)^b
Implantation	1,142	7.5	230	7.5	1.01 (0.84, 1.21)	0.98 (0.83, 1.17)
Clinical pregnancy	1,125	20.9	222	19.6	1.08 (0.82, 1.43)	1.05 (0.81, 1.35)
Live birth	691	12.9	128	11.3	1.16 (0.90, 1.49)	1.12 (0.89, 1.40)
Miscarriage	391	34.9	85	38.6	0.85 (0.63, 1.15)	0.86 (0.64, 1.17)
Multiple gestation	160	14.2	38	17.1	0.80 (0.56, 1.14)	0.78 (0.55, 1.10)

Note: aOR = adjusted odds ratio; ART = assisted reproductive technology; CI = confidence interval; OR = odds ratio.

Outcomes are not mutually exclusive, and numbers/percentages may not add up due to missing values. Percentages of implantation are calculated per embryo transferred; clinical pregnancy and live birth are calculated per embryo transfer; percentages of miscarriage and multiple gestation are calculated per clinical pregnancy.

Poor-prognosis patients include women who are ≥38 years of age, have had ≥2 prior ART cycles (fresh or frozen) and no prior live birth(s), have FSH ≥10 mIU/mL, have a diagnosis of diminished ovarian reserve, and have no extra embryos available for cryopreservation.

Multivariable analysis considered via reporting year and all patient and treatment characteristics shown in Table 1, excluding race/ethnicity. Final models in the first three patient groups included extra embryos cryopreserved (yes, no), number of oocytes retrieved (0–10, 11–20, 21+) for implantation, and number of embryos transferred (1, 2+) and interaction between assisted hatching and the number of embryos transferred for other outcomes; final models in poor-prognosis group included reporting year and ovulatory dysfunction (yes, no) for implantation, and number of embryos transferred (1, 2+) for other outcomes. In supplemental analyses, magnitude and direction of effect did not change significantly when race/ethnicity was included in the final models.

Kissin. Assisted hatching trends and outcomes. Fertil Steril 2014.