OBJECTIVE:To investigate whether the addition of embryo biopsy performed during preimplantation genetic testing for monogenic diseases is associated with a higher risk of obstetric and neonatal complications compared with in vitro fertilization (IVF) without preimplantation genetic testing or spontaneously conceived pregnancies.METHODS:This is a cohort study of all pregnancies conceived after preimplantation genetic testing for monogenic diseases (PGT-M group) from 2006 to 2018 at Sheba Medical Center, Israel. The control groups included patients who had conceived spontaneously (spontaneous conception group) or by IVF without preimplantation genetic testing (IVF group) and delivered at Sheba Medical Center. The obstetrics outcomes were compared among the groups. Multivariable regression modeling was performed, focusing on the relationship between preimplantation genetic testing and adverse outcomes.RESULTS:Final analysis included 345 singleton and 76 twin deliveries in the PGT-M group. The spontaneous conception group included 5,290 singleton and 92 twin deliveries. The IVF group included 422 singleton and 101 twin deliveries. Among singleton pregnancies, patients in the PGT-M group had a higher rate of hypertensive disorders (6.9%) compared with those in the spontaneous conception group (2.3%; odds ratio [OR] 3.3; 95% CI 1.9-4.8; adjusted odds ratio [aOR] 14.8; 95% CI 7.4-29.8) and the IVF group (4.7%; OR 1.5; 95% CI 0.8-2.7; aOR 5.9; 95% CI 1.9-18.2). Likewise, patients in the PGT-M group had a higher rate of small-for-gestational age neonates (12.4%) compared with those in the spontaneous conception group (3.9%; OR 3.4; 95% CI 2.4-4.9; aOR 2.3; 95% CI 1.5-3.4) and the IVF group (4.5%; OR 3; 95% CI 1.7-5.2; aOR 2.5; 95% CI 1.7-5.2). Among twin pregnancies, patients in the PGT-M group also had an increased rate of hypertensive disorders compared with those in the spontaneous conception group (4.3%; OR 4.1; 95% CI 1.2-13.3; aOR 10.9; 95% CI 2.3-50) and the IVF group (4%; OR 4.5; 95% CI 1.4-14.7; aOR 3.7; 95% CI 1.1-12.8).CONCLUSION:Pregnancies conceived after preimplantation genetic testing for monogenic disorders were associated with an increased risk of obstetric complications compared with pregnancies conceived spontaneously or by IVF without preimplantation genetic testing.