Question: If a woman aborted a child at an early stage due to family planning, will this affect her rebirth?
Answer: According to the Buddha’s teachings, the moment of conception is the moment there is sentient life already. Actually, true family planning in this case should mean planning not to possibly conceive in the first place, such as by abstinence or use of contraceptives. To conceive and then abort is the lack of family planning. The negative karma created from intentional abortion, especially with clear understanding that a human life is taken is very heavy. The killing of a human life is especially grave as humans are the ones with most potential to learn and practise the Dharma among the six realms of samsaric existence. This might create the result of oneself being born in the lower realms.
Question: How can she overcome the negative karma?
Answer: There must be utmost sincere repentance and remedial action for the rest of this life – until there is true peace of mind or auspicious signs of repentance being complete. Repentance can be practised in many ways, such as the following:
 Regular sincere chanting of the ‘Verse For Repentance’ (https://thedailyenlightenment.com/2011/11/verse-for-repentance-%E5%BF%8F%E6%82%94%E6%96%87) with reverent prostration to Buddha.  Regular sincere Nianfo, which is chanting of Amitabha Buddha’s name ‘Amituofo’ for connection to him, for blessings to help dissolve negative karma. Proper lifelong and deathbed Nianfo practice will prevent a lower rebirth, reaching Pure Land instead.
 Regular sincere proper animal liberation, which creates much positive karma as it is the saving of lives; the opposite of taking life.  Going vegetarian, or ideally vegan, lifelong or as much and regularly as possible, which protects and saves many lives. (Veganism means going meat-free with non-consumption and use of animal by-products as well, such as dairy produce, eggs, honey, leather… which necessitate ongoing exploitation leading to eventual killing of animals these days.)
 Regular sincere signing up the name (or token name) of the aborted child during Dharma ceremonies (法会) for creating guidance and merits to help the consciousness of the deceased to have a better rebirth, if still around. If already reborn, the merits will help alleviate suffering and expedite a better rebirth. The ceremonies are ideally personally participated in too.
 Regular sincere sponsorship of printing of Dharma books to share the Dharma, which the Buddha taught to be the gift that excels all other gifts, as it offers all the path to Buddhahood. As such, this creates immense merits too.  Regular sincere doing of other various good deeds to help others… As much as possible, if not all of the above should be done. All the merits from doing the above should be dedicated to all beings, followed by the deceased.
Should Sick Babies Be Aborted?
Please Be Mindful Of Your Speech, Namo Amituofo!