Humans say it is a human right not to be excluded from medical procedures based on sex. Not allowing women access to medical procedures is discrimination.
Science says when a fetus is viable based on the study of human developmental biology.
There are many abortions performed when the fetus would have been able to survive if it had been delivered rather than aborted. These abortions are the most clearly wrong. With advancements in medical technology, viability outside the womb has become increasingly earlier in pregnancy over time.
Restrictions on abortion are not prohibiting women from receiving abortions based on their sex.
Abortions until viability is a decision only the mother should be taking. Science tells us that viability is around 22-24 weeks.
If you want to be on the side of caution, make the laws allowing all abortions until 16 weeks, or thereabouts.
Restrictions on abortions implicitly discriminate against women.
Imagine if states had different laws against receiving cancer treatments based on the size of your prostate. Some states would allow treatments as soon as the cancer is detected, others will say that your prostate has to be larger than 4 inches. Most men with prostate cancer will be prevented from receiving their treatment in that state. The laws would discriminate against them without explicitly stating that men are prevented from receiving cancer treatment.