PCSK9 and neural tube defect: Similarly, compared with the control group, the serum level of PCSK9 in the NTD group was significantly lower at a gestational age of 23–27 weeks (240.56 ± 56.39 ng/ml vs. 333.23 ± 66.40 ng/ml, p < 0.01) and at a gestational age of 37–40 weeks (322.50 ± 80.39 ng/ml vs. 456.03 ± 58.70 ng/ml, p < 0.01; Fig. 6b).