The occurrence of OHSS-associated hospitalizations increases the economic burden and affects patient mental wellbeing after IVF-ET [25]. However, different races, different regions, hospitals or research methods may affect the impact of OHSS on pregnancy outcomes, such as baseline characteristics or severity of OHSS confounders patient may affect the interpretation of results during the course of clinical research. The pregnancy outcomes of pregnancies effected by OHSS has not yet been investigated thoroughly and further studies are needed[8, 12].
We found the incidence of OHSS was significantly higher in the multiple than that in the singleton pregnancy, which is consistent with previous findings [14]. The results of our data in the OHSS group and the unmatched control group showed that the rates of multiple live birth delivery and LBW were significantly higher in the OHSS group.
After eliminating the impacts of multiple pregnancies and nine baseline characteristics on perinatal complications using propensity score matching. Furthermore, the results of our data in the OHSS group and the matched control group showed that the incidence rates of obstetric complications and neonatal complications were significantly higher in the OHSS group than those in the control group, including the incidence of GDM, VT, congenital disorders and neonatal NICU hospitalization. No significant between-group differences with respect to the rates of preterm delivery, miscarriage, early miscarriage.
A previous case-control study reported that the hospitalization duration of OHSS patients was positively related to the increase in the rate of miscarriage, and OHSS hospitalization was not conducive to pregnancy or continued pregnancy in patients who underwent IVF [18]. All the patients in two groups were included in the clinical pregnancy, the abortion rate of the unmatched control group was higher than the OHSS group, but there was no statistical difference (12.2% vs. 15.4%, P = 0.098). There was no difference in the abortion rate between the two groups after matching. 12.2% vs. 13.6%, P = 0.481). It is possible that the occurrence and treatment of OHSS does not affect the abortion rate.
In our study, obstetric complications were significantly higher in the OHSS group than those in the control group, but the incidence rates of PP, PIH, and ICP were not increased after OHSS, and the rates were consistent with previously reported post-IVF rates [25, 26]. Our results were similar to several previous reports that assessed this outcome [12, 14]. A previous symposium by Raziel et al. in 2009 and a previous case-control study indicated that the pregnancy rate is increased in OHSS patients and that the incidence rates of multiple pregnancy, GDM, premature birth, and LBW infants are significantly higher in OHSS [8]. We observed thrombosis only appear in the OHSS group. These results are somewhat inconsistent with previous findings because the obstetric complications examined here were not evaluated in previous studies[8, 13, 14].
A previous study model suggested that outpatient treatment of moderate-to-severe OHSS with early intervention using paracentesis is the most cost-effective management option [27]. Furthermore, a previous study indicated that repeated abdominal paracentesis has no adverse effects on pregnancy outcomes in severe OHSS[28]. Patients who undergo paracentesis are not at risk for obstetric complications. The observed increased prevalence of obstetric complications (11.6%) in our study is consistent with findings from previous studies [29].
At admission, HCT and WBC values were positively correlated with the degree of OHSS and patient symptoms and were associated with an increased rate of surgical treatment. The number of hospital stays in the severe-critical group increased compared with that in the moderate group, and obstetric complications decreased; however, neonatal complications increased, as shown in Table 3. The severity of OHSS increased the incidence rates of obstetrical complications and preterm delivery but had no effect on neonatal complications.